Journal articles: 'Nozzle guide vane'

1

Plante, Robert D. "The Nozzle Guide Vane Problem." Operations Research 36, no. 1 (February 1988): 18–33. http://dx.doi.org/10.1287/opre.36.1.18.

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Yang, Dengfeng, Ce Yang, Dazhong Lao, and Tao Zeng. "A detailed investigation of a variable nozzle turbine with novel forepart rotation guide vane." Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 233, no. 4 (February 25, 2018): 994–1007. http://dx.doi.org/10.1177/0954407018757244.

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One of the disadvantages of a variable nozzle turbine in practical application is the stage performance degradation due to nozzle endwall leakage flow at small nozzle openings. Aiming at restricting the nozzle leakage flow rate to improve turbine stage performance, a novel forepart rotation guide vane has been proposed and numerically studied in present work. First, the numerical results of baseline turbine were validated by experimental data to ensure the accuracy of numerical methods. Then steady and unsteady simulations were performed on both baseline and forepart rotation guide vane turbines to demonstrate the effectiveness of the novel vane and to study the characteristics of nozzle leakage flow, respectively. Results indicate that there is up to 13.5% peak efficiency improvement that has been achieved at 10% nozzle opening with the forepart rotation guide vane design; besides, rotor–stator interaction for forepart rotation guide vane is also mitigated due to the reduced nozzle leakage flow rate, thus the intensity of loading fluctuation on rotor blades is weakened significantly, which is beneficial to improve rotor blade forced response.

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3

Shaikh, Faisal, and Budimir Rosic. "Unsteady phenomena at the combustor-turbine interface." Journal of the Global Power and Propulsion Society 5 (November 23, 2021): 202–15. http://dx.doi.org/10.33737/jgpps/143042.

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The combustor-turbine interface in a gas turbine is characterised by complex, highly unsteady flows. In a combined experimental and large eddy simulation (LES) study including realistic combustor geometry, the standard model of secondary flows in the nozzle guide vanes (NGV) is found to be oversimplified. A swirl core is created in the combustion chamber which convects into the first vane passages. Four main consequences of this are identified: variation in vane loading; unsteady heat transfer on vane surfaces; unsteadiness at the leading edge horseshoe vortex, and variation in the position of the passage vortex. These phenomena occur at relatively low frequencies, from 50–300 Hz. It seems likely that these unsteady phenomena result in non-optimal film cooling, and that by reducing unsteadiness designs with greater cooling efficiency could be achieved. Measurements were performed in a high speed test facility modelling a large industrial gas turbine with can combustors, including nozzle guide vanes and combustion chambers. Vane surfaces and endwalls of a nozzle guide vane were instrumented with 384 high speed thin film heat flux gauges, to measure unsteady heat transfer. The high resolution of measurements was such to allow direct visualisation in time of large scale turbulent structures over the endwalls and vane surfaces. A matching LES simulation was carried out in a domain matching experimental conditions including upstream swirl generators and transition duct. Data reduction allowed time-varying LES data to be recorded for several cycles of the unsteady phenomena observed. The combination of LES and experimental data allows physical explanation and visualisation of flow events.

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Yang, Dengfeng, Kai Wang, Huaiyu Wang, Qian Zhang, Xinguo Lei, and Leon Hu. "An Investigation of the Performance and Internal Flow of Variable Nozzle Turbines with Split Sliding Guide Vanes." Machines 10, no. 11 (November 16, 2022): 1084. http://dx.doi.org/10.3390/machines10111084.

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In order to effectively weaken the leakage flow and shock intensity of traditional “swing” type guide vanes in a variable nozzle turbine, a new flow control device named the “split sliding guide vane” (SSGV) is studied in the present work. Steady and unsteady calculations were carried out on both the SSGV and base model at 10%, 40%, and 100% open positions. The shock test was performed to verify the accuracy of the numerical method. The results showed that at 10%, 40%, and 100% open positions, the leakage flow of the SSGV was 43%, 51%, and 40% of that of the base model, respectively. When 10% open, the turbine efficiency increased by 12%, compared with the base model, since the SSGV could effectively inhibit the clearance leakage flow. Due to the increased distance between the rotor and guide vane, the shock intensity of the SSGV was only 52% of that of the base model when 40% was open. The SSGV could reduce the static pressure loss on the guide vane pressure surface, but for the guide vane suction surface, the static pressure distribution appeared in a “W” shape due to the influence of the vane profile. Finally, the flow in the rotor was studied, which showed that the weakening of the shock and reduction of the clearance leakage flow in the guide vane were also beneficial for the strength of downstream rotor blades.

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5

Balakrishnan, Anantaram, Robert Plante, and Richard Wong. "The nozzle guide vane problem: Partitioning a heterogeneous inventory." European Journal of Operational Research 35, no. 3 (June 1988): 328–38. http://dx.doi.org/10.1016/0377-2217(88)90223-8.

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Pujari, Arun Kumar, B. V. S. S. S. Prasad, and Nekkanti Sitaram. "Conjugate Heat Transfer Analysis on the Interior Surface of Nozzle Guide Vane with Combined Impingement and Film Cooling." International Journal of Turbo & Jet-Engines 37, no. 4 (November 18, 2020): 327–42. http://dx.doi.org/10.1515/tjj-2017-0026.

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AbstractThe effect of conjugate heat transfer is investigated on a first stage nozzle guide vane (NGV) of a high pressure gas turbine which has both impingement and film cooling holes. The study is carried out computationally by considering a linear cascade domain, having two passages formed between the vanes, with a chord length of 228 mm and spacing of 200 mm. The effect of (i) coolant and mainstream Reynolds numbers, (ii) thermal conductivity (iii) temperature difference between the mainstream and coolant at the internal surface of the nozzle guide vane are investigated under conjugate thermal condition. The results show that, with increasing coolant Reynolds number the lower conducting material shows larger percentage decrease in surface temperature as compared to the higher conducting material. However, the internal surface temperature is nearly independent of mainstream Reynolds number variation but shows significant variation for higher conducting material. Further, the temperature gradient within the solid thickness of NGV is higher for the lower conductivity material.

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7

Sargison, J. E., S. M. Guo, M. L. G. Oldfield, G. D. Lock, and A. J. Rawlinson. "A Converging Slot-Hole Film-Cooling Geometry—Part 2: Transonic Nozzle Guide Vane Heat Transfer and Loss." Journal of Turbomachinery 124, no. 3 (July 1, 2002): 461–71. http://dx.doi.org/10.1115/1.1459736.

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This paper presents the first experimental measurements on an engine representative nozzle guide vane, of a new film-cooling hole geometry, a con¯vergings¯lot-hole¯ or console. The patented console geometry is designed to improve the heat transfer and aerodynamic performance of turbine vane and rotor blade cooling systems. These experiments follow the successful validation of the console design in low-speed flat-plate tests described in Part 1 of this paper. Stereolithography was used to manufacture a resin model of a transonic, engine representative nozzle guide vane in which seven rows of previously tested fan-shaped film-cooling holes were replaced by four rows of consoles. This vane was mounted in the annular vane ring of the Oxford cold heat transfer tunnel for testing at engine Reynolds numbers, Mach numbers and coolant to mainstream momentum flux ratios using a heavy gas to simulate the correct coolant to mainstream density ratio. Heat transfer data were measured using wide-band thermochromic liquid crystals and a modified analysis technique. Both surface heat transfer coefficient and the adiabatic cooling effectiveness were derived from computer-video records of hue changes during the transient tunnel run. The cooling performance, quantified by the heat flux at engine temperature levels, of the console vane compares favourably with that of the previously tested vane with fan-shaped holes. The new console film-cooling hole geometry offers advantages to the engine designer due to a superior aerodynamic efficiency over the fan-shaped hole geometry. These efficiency measurements are demonstrated by results from midspan traverses of a four-hole pyramid probe downstream of the nozzle guide vane.

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8

Krishnamoorthy, V., B. R. Pai, and S. P. Sukhatme. "Influence of Upstream Flow Conditions on the Heat Transfer to Nozzle Guide Vanes." Journal of Turbomachinery 110, no. 3 (July 1, 1988): 412–16. http://dx.doi.org/10.1115/1.3262212.

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The influence of a combustor located just upstream of a nozzle guide vane cascade on the heat flux distribution to the nozzle guide vane was experimentally investigated. The surface temperature distribution around the convectively cooled vane of the cascade was obtained by locating the cascade, firstly in a low-turbulence uniform hot gas stream, secondly in a high-turbulence, uniform hot gas stream, and thirdly in a high-turbulence, nonuniform hot gas stream present just downstream of the combustor exit. The results indicate that the increased blade surface temperatures observed for the cascade placed just downstream of the combustor can be accounted for by the prevailing turbulence level measured at cascade inlet in cold-flow conditions and the average gas temperature at the cascade inlet.

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9

Flaszynski, Pawel, Michal Piotrowicz, and Tommaso Bacci. "Clocking and Potential Effects in Combustor–Turbine Stator Interactions." Aerospace 8, no. 10 (October 2, 2021): 285. http://dx.doi.org/10.3390/aerospace8100285.

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Investigations of combustors and turbines separately have been carried out for years by research institutes and aircraft engine companies, but there are still many questions about the interaction effect. In this paper, a prediction of a turbine stator’s potential effect on flow in a combustor and the clocking effect on temperature distribution in a nozzle guide vane are discussed. Numerical simulation results for the combustor simulator and the nozzle guide vane (NGV) of the first turbine stage are presented. The geometry and flow conditions were defined according to measurements carried out on a test section within the framework of the EU FACTOR (full aerothermal combustor–turbine interactions research) project. The numerical model was validated by a comparison of results against experimental data in the plane at a combustor outlet. Two turbulence models were employed: the Spalart–Allmaras and Explicit Algebraic Reynolds Stress models. It was shown that the NGV potential effect on flow distribution at the combustor–turbine interface located at 42.5% of the axial chord is weak. The clocking effect due to the azimuthal position of guide vanes downstream of the swirlers strongly affects the temperature and flow conditions in a stator cascade.

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10

Baines, N. C., M. L. G. Oldfield, J. P. Simons, and J. M. Wright. "The Aerodynamic Development of a Highly Loaded Nozzle Guide Vane." Journal of Turbomachinery 108, no. 2 (October 1, 1986): 261–68. http://dx.doi.org/10.1115/1.3262046.

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A series of high-pressure turbine nozzle guide vanes has been designed for progressively increasing blade loading and reduction in blade solidity without additional loss penalty. Early members of the series achieved this by changes to the suction surface contour, but for the latest design the pressure surface contour was extensively modified to reduce the velocities on this surface substantially. Cascade testing revealed that this vane had a higher loss than its predecessor, and this appears to be largely due to a long region of boundary layer growth on the suction surface and possibly also an unsteady separation. These tests demonstrated the value of a flattened pitot tube held against the blade surface in determining the boundary layer state. By using a pitot probe of only modest frequency response (of order 100 Hz) it was possible to observe significant qualitative differences in the raw signals from laminar, transitional and turbulent boundary layers, which have previously been observed only with much higher frequency instruments. The test results include a comparison of boundary layer measurements on the same cascade test section in two different high-speed wind tunnels. This comparison suggests that freestream turbulence can have a large effect on boundary layer development and growth.

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11

Barringer, M. D., O. T. Richard, J. P. Walter, S. M. Stitzel, and K. A. Thole. "Flow Field Simulations of a Gas Turbine Combustor." Journal of Turbomachinery 124, no. 3 (July 1, 2002): 508–16. http://dx.doi.org/10.1115/1.1475742.

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The flow field exiting the combustor in a gas turbine engine is quite complex considering the presence of large dilution jets and complicated cooling schemes for the combustor liner. For the most part, however, there has been a disconnect between the combustor and turbine when simulating the flow field that enters the nozzle guide vanes. To determine the effects of a representative combustor flow field on the nozzle guide vane, a large-scale wind tunnel section has been developed to simulate the flow conditions of a prototypical combustor. This paper presents experimental results of a combustor simulation with no downstream turbine section as a baseline for comparison to the case with a turbine vane. Results indicate that the dilution jets generate turbulence levels of 15–18% at the exit of the combustor with a length scale that closely matches that of the dilution hole diameter. The total pressure exiting the combustor in the near-wall region neither resembles a turbulent boundary layer nor is it completely uniform putting both of these commonly made assumptions into question.

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12

Harasgama, S. P., and E. T. Wedlake. "Heat Transfer and Aerodynamics of a High Rim Speed Turbine Nozzle Guide Vane Tested in the RAE Isentropic Light Piston Cascade (ILPC)." Journal of Turbomachinery 113, no. 3 (July 1, 1991): 384–91. http://dx.doi.org/10.1115/1.2927887.

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Detailed heat transfer and aerodynamic measurements have been made on an annular cascade of highly loaded nozzle guide vanes. The tests were carried out in an Isentropic Light Piston test facility at engine representative Reynolds number, Mach number, and gas-to-wall temperature ratio. The aerodynamics indicate that the vane has a weak shock at 65–70 percent axial chord (midspan) with a peak Mach number of 1.14. The influence of Reynolds number and Mach number on the Nusselt number distributions on the vane and endwall surfaces are shown to be significant. Computational techniques are used for the interpretation of test data.

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13

Jenkins, Sean, Krishnakumar Varadarajan, and David G. Bogard. "The Effects of High Mainstream Turbulence and Turbine Vane Film Cooling on the Dispersion of a Simulated Hot Streak." Journal of Turbomachinery 126, no. 1 (January 1, 2004): 203–11. http://dx.doi.org/10.1115/1.1643911.

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This paper presents the combined effects of high turbulence and film cooling on the dispersion of a simulated hot streak as it passes over a scaled-up nozzle guide vane. Experimental data demonstrates a considerable decay in the strength of a hot streak due to turbulence effects alone. Film cooling further reduces the peak temperature values resulting in a reduction of the peak temperature in the hot streak on the order of 75% relative to the upstream peak temperature in the hot streak. Comparisons are made between high turbulence Tu=20% and moderate turbulence Tu=3.5% as well as between different blowing conditions for the suction side, showerhead, and pressure side film cooling holes on a simulated nozzle guide vane.

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14

Boletis, E. "Effects of Tip Endwall Contouring on the Three-Dimensional Flow Field in an Annular Turbine Nozzle Guide Vane: Part 1—Experimental Investigation." Journal of Engineering for Gas Turbines and Power 107, no. 4 (October 1, 1985): 983–90. http://dx.doi.org/10.1115/1.3239845.

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Tip endwall contouring is one of the most effective methods to improve the performance of low aspect ratio turbine vanes [1]. In view of the wide variety of geometric parameters, it appears that only the physical understanding of the three-dimensional flow field will allow us to evaluate the probable benefits of a particular endwall contouring. The paper describes the experimental investigation of the three-dimensional flow through a low-speed, low aspect ratio, high-turning annular turbine nozzle guide vane with meridional tip endwall contouring. The full impact of the effects of tip contouring is evaluated by comparison with the results of a previous study in an annular turbine nozzle guide vane of the same blade and cascade geometry with cylindrical endwalls [12]. In parallel, the present experimental study provides a fully three-dimensional test case for comparison with advanced theoretical calculation methods [15]. The flow is explored by means of double-head, four-hole pressure probes in five axial planes from far upstream to downstream of the blade row. The results are presented in the form of contour plots and spanwise pitch-averaged distributions.

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15

Sato, K., and L. He. "Numerical investigation into the effects of a radial gap on hydraulic turbine performance." Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy 215, no. 1 (February 1, 2001): 99–107. http://dx.doi.org/10.1243/0957650011536462.

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The effects of the rotor/stator blade row interaction on the performance of radial turbine stages are investigated numerically. A three-dimensional unsteady incompressible Navier-Stokes method based on the dual-time stepping and the pseudocompressibility method is developed for the performance prediction. A centrifugal pump with a vaned diffuser is calculated for validation purposes, and the predicted unsteady flow results show reasonable agreement with the experimental data. The method is applied to analysis of hydraulic turbine stages. A generic turbine rotor is combined with a row of nozzle guide vanes with three settings of radial gap and numerical flow simulations are conducted for the performance evaluations. The predicted efficiency of the hydraulic turbine stages deteriorates if the radial gap between blade rows is reduced although the difference is very small. The entropy rises along the streamlines suggest that the differences in the stage efficiency level can be largely attributed to the loss generated in the nozzle vane passages.

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16

Sznajder, Janusz. "Simulations of Hot-Gas Flow in Internally Cooled Cascade of Turbine Vanes." Journal of KONES 26, no. 2 (June 1, 2019): 151–58. http://dx.doi.org/10.2478/kones-2019-0044.

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Abstract An experiment in cooling of gas turbine nozzle guide vanes was modelled numerically with a conjugate viscous-flow and solid-material heat conduction solver. The nozzle vanes were arranged in a cascade and operated in high-pressure, hot-temperature conditions, typical for first turbine stage in a flow of controlled-intensity, artificially-generated turbulence. The vane cooling was internal, accomplished by 10 channels in each vane with cooling-air flow. Numerical simulations of the experiment were conducted applying two turbulence models of the k-omega family: k-omega-SST and Transition SST implemented in the ANSYS Fluent solver. Boundary conditions for the simulations were set based on conditions of experiment: total pressures and total temperature on inlet to cascade, static pressure on the outlet of the cascade and heat flux on the surface of cooling channels. The values of heat flux on the surface of cooling channels were evaluated based on Nusselt numbers obtained from experiment and varied in time until steady-state conditions were obtained. Two test cases, one with subcritical outlet flow, and another one, with supercritical outlet flow were simulated. The result of experiment – distributions of pressure, surface temperature, and heat transfer coefficients on the vane external surface were compared to results of numerical simulations. Sensitivity of the vane surface temperatures and heat transfer coefficients to turbulence models and to boundary-condition values of parameters of turbulence models: turbulence energy and specific dissipation of turbulence energy was also studied.

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Sanaye, Sepehr, and Salahadin Hosseini. "Off-design performance improvement of twin-shaft gas turbine by variable geometry turbine and compressor besides fuel control." Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy 234, no. 7 (December 3, 2019): 957–80. http://dx.doi.org/10.1177/0957650919887888.

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A novel procedure for finding the optimum values of design parameters of industrial twin-shaft gas turbines at various ambient temperatures is presented here. This paper focuses on being off design due to various ambient temperatures. The gas turbine modeling is performed by applying compressor and turbine characteristic maps and using thermodynamic matching method. The gas turbine power output is selected as an objective function in optimization procedure with genetic algorithm. Design parameters are compressor inlet guide vane angle, turbine exit temperature, and power turbine inlet nozzle guide vane angle. The novel constrains in optimization are compressor surge margin and turbine blade life cycle. A trained neural network is used for life cycle estimation of high pressure (gas generator) turbine blades. Results for optimum values for nozzle guide vane/inlet guide vane (23°/27°–27°/6°) in ambient temperature range of 25–45 ℃ provided higher net power output (3–4.3%) and more secured compressor surge margin in comparison with that for gas turbines control by turbine exit temperature. Gas turbines thermal efficiency also increased from 0.09 to 0.34% (while the gas generator turbine first rotor blade creep life cycle was kept almost constant about 40,000 h). Meanwhile, the averaged values for turbine exit temperature/turbine inlet temperature changed from 831.2/1475 to 823/1471°K, respectively, which shows about 1% decrease in turbine exit temperature and 0.3% decrease in turbine inlet temperature.

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18

Duan, Franklin Li, Ziyi Xie, Zhonglin Ji, and Haotian Weng. "Robust Thin-Film Temperature Sensors Embedded on Nozzle Guide Vane Surface." AIAA Journal 58, no. 4 (April 2020): 1441–45. http://dx.doi.org/10.2514/1.j058854.

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19

Zheng, Xin-qian, Tao Du, and Yang-jun Zhang. "Prediction of thermal fatigue life of a turbine nozzle guide vane." Journal of Zhejiang University-SCIENCE A 12, no. 3 (March 2011): 214–22. http://dx.doi.org/10.1631/jzus.a1000233.

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20

Wedlake, E. T., A. J. Brooks, and S. P. Harasgama. "Aerodynamic and Heat Transfer Measurements on a Transonic Nozzle Guide Vane." Journal of Turbomachinery 111, no. 1 (January 1, 1989): 36–42. http://dx.doi.org/10.1115/1.3262234.

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Experimental determination of heat transfer rates to gas turbine blading plays an important part in the improvement of both the validation of existing design methods and the development of improved design codes. This paper describes a series of tests on an annular cascade of nozzle guide vanes designed for a high-work-capacity single-stage transonic turbine. The tests were carried out in the Isentropic Light Piston Cascade at the Royal Aerospace Establishment, Pyestock, and a brief description of this new test facility is included. Measurements of local heat transfer rates and aerodynamic data around the blade surface and on the end walls are described.

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21

Harvey, N. W., M. G. Rose, J. Coupland, and T. V. Jones. "Measurement and Calculation of Nozzle Guide Vane End Wall Heat Transfer." Journal of Turbomachinery 121, no. 2 (April 1, 1999): 184–90. http://dx.doi.org/10.1115/1.2841300.

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A three-dimensional steady viscous finite volume pressure correction method for the solution of the Reynolds-averaged Navier–Stokes equations has been used to calculate the heat transfer rates on the end walls of a modern High Pressure Turbine first-stage stator. Surface heat transfer rates have been calculated at three conditions and compared with measurements made on a model of the vane tested in annular cascade in the Isentropic Light Piston Facility at DERA, Pyestock. The NGV Mach numbers, Reynolds numbers, and geometry are fully representative of engine conditions. Design condition data have previously been presented by Harvey and Jones (1990). Off-design data are presented here for the first time. In the areas of highest heat transfer, the calculated heat transfer rates are shown to be within 20 percent of the measured values at all three conditions. Particular emphasis is placed on the use of wall functions in the calculations with which relatively coarse grids (of around 140,000 nodes) can be used to keep computational run times sufficiently low for engine design purposes.

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Yavari, Hadi, Ali Khavari, Mohammad Alizadeh, Behrad Kashfi, and Hiwa Khaledi. "Aero-thermal redesign of a high pressure turbine nozzle guide vane." Propulsion and Power Research 8, no. 4 (December 2019): 310–19. http://dx.doi.org/10.1016/j.jppr.2019.01.012.

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23

Wang, Wei, Jianmin Gao, Xiaojun Shi, and Liang Xu. "Cooling performance analysis of steam cooled gas turbine nozzle guide vane." International Journal of Heat and Mass Transfer 62 (July 2013): 668–79. http://dx.doi.org/10.1016/j.ijheatmasstransfer.2013.02.080.

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24

Robak, R., M. Szczepanik, and S. Rulik. "Frequency optimization of nozzle guide vane in the low-pressure turbine system." IOP Conference Series: Materials Science and Engineering 1235, no. 1 (March 1, 2022): 012046. http://dx.doi.org/10.1088/1757-899x/1235/1/012046.

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Abstract The aim of the article is to present the approach for modal optimisation of nozzle guide vane in the low-pressure turbine system of aircraft engine. Described analysis assumption related to the finite element model definition, meta-model estimation and optimisation process itself. Goal function has been determined basing on Campbell diagram. Typical approach to solve modal analysis for mentioned structure is full three-dimensional model that is time consuming. For optimisation purposes employed two dimensional one in order to make the process more robust (element types with support of Fourier series). This approach is reducing degree of freedom quantity and is still capable to consider non-axisymmetric structure behaviour. The article provides relationship between geometrical features of nozzle and frequency change.

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Reddy Kukutla, Pol, and BVSSS Prasad. "Network analysis of a coolant flow performance for the combined impingement and film cooled first-stage of high pressure gas turbine nozzle guide vane." Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering 233, no. 6 (April 16, 2018): 1977–89. http://dx.doi.org/10.1177/0954410018767290.

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The present paper describes a system-level thermo-fluid network analysis for the secondary air system analysis of a typically film-cooled nozzle guide vane with multiple actions of jet impingement. The one-dimensional simulation was done with the help of the commercially available Flownex 2015 software. The system-level thermo-fluid network results were validated with both the computational fluid dynamics results and experimentally available literature. The entire nozzle guide vane geometry was first mapped to a thermo-fluid network model and the pressure conditions at different nodes. The discharge and heat transfer coefficients obtained from the Ansys FLUENT were specified as inputs to the thermo-fluid network model. The results show that the one-dimensional simulation of the coolant mass flow rates and jet Nusselt number values are in good agreement with the three-dimensional computational fluid dynamics results.

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Mustafa, Alaaeldin H. "Failure Analysis of Heavy Industrial Gas Turbine Engine First Stage Nozzel Guide Vane." Advanced Materials Research 445 (January 2012): 1047–52. http://dx.doi.org/10.4028/www.scientific.net/amr.445.1047.

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Failure analysis investigation was conducted on 70 MW set of 1st stage turbine nozzle guide vanes (NGVs) of heavy industrial gas turbine. The failure was investigated using the light optical microscope (LOM), X-ray diffraction analysis (XRD) and energy dispersive X-ray spectroscopy (EDS) in an environmental scanning electron microscope (ESEM). The results of the analysis indicate that the NGVs which were made of Co base superalloy FSX-414 had been operated above the recommended operating hours under different fuel types in addition to inadequate repair process in previous repair removal. The XRD analysis of the fractured areas sample shows presence ofwhich might indicate the prolonged operation at high temperature. Keywords: cobalt-base; nozzle guide vanes, gas turbine.

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Zaidi, Sohail H., and Robin L. Elder. "Flow Studies using Laser Anemometry Technique in a Small Power Unit Radial Inflow Turbine." International Journal of Rotating Machinery 3, no. 2 (1997): 107–15. http://dx.doi.org/10.1155/s1023621x97000110.

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T-100 is a multipurpose small power unit developed by Sundstrand Power Systems (USA). An extensive research programme was launched for the detailed tests of the rig components including inlet protection system, Compressor stage, Combustor and the Turbine stage. Turbomachinery Group at Cranfield was involved in the study of the Turbine unit used in this programme. From the design point of view, detailed aerodynamics in these small units are of great interest especially where high velocities and narrow passages are involved. Experimental study was carried out to investigate the flow in the region between the nozzle guide vanes and the turbine rotor entry. The main concern was to find out how the nozzle guide vane flow was modified by the rotor and how the rotor flow was affected by the nozzle guide vanes. Laser measurements were taken at these positions for various flow conditions. An other area which needs considerable attention is downstream of the turbine rotor where the turning of flow and mixing process make the situation very complicated. Laser studies were undertaken in that region and to gain more confidence on laser results, a Cobra pressure probe was traversed at these stations. This paper describes various steps undertaken to obtain laser results within the machine. At the end typical laser results have been presented and discussed.

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28

Froissart, Marcin, and Tomasz Ochrymiuk. "Thermal-Fluid–Solid Coupling—Parametrical Numerical Analysis of Hot Turbine Nozzle Guide Vane." Materials 14, no. 23 (November 29, 2021): 7313. http://dx.doi.org/10.3390/ma14237313.

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The cooling technology of hot turbine components has been a subject of continuous improvement for decades. In high-pressure turbine blades, the regions most affected by the excessive corrosion are the leading and trailing edges. In addition, high Kt regions at the hot gas path are exposed to cracking due to the low and high cycle fatigue failure modes. Especially in the case of a nozzle guide vane, the ability to predict thermally driven loads is crucial to assess its life and robustness. The difficulties in measuring thermal properties in hot conditions considerably limit the number of experimental results available in the literature. One of the most popular test cases is a NASA C3X vane, but coolant temperature is not explicitly revealed in the test report. As a result of that, numerous scientific works validated against that vane are potentially inconsistent. To address that ambiguity, the presented work was performed on a fully structural and a very fine mesh assuming room inlet temperature on every cooling channel. Special attention was paid to the options of the k−ω SST (shear-stress transport) viscosity model, such as Viscous heating (VH), Curvature correction (CC), Production Kato-Launder (KT), and Production limiter (PL). The strongest impact was from the Viscous heating, as it increases local vane temperature by as much as 40 deg. The significance of turbulent Prandtl number impact was also investigated. The default option used in the commercial CFD code is set to 0.85. Presented study modifies that value using equations proposed by Wassel/Catton and Kays/Crawford. Additionally, the comparison between four, two, and one-equation viscosity models was performed.

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Ames, F. E., M. Argenziano, and C. Wang. "Measurement and Prediction of Heat Transfer Distributions on an Aft-Loaded Vane Subjected to the Influence of Catalytic and Dry Low NOx Combustor Turbulence." Journal of Turbomachinery 126, no. 1 (January 1, 2004): 139–49. http://dx.doi.org/10.1115/1.1645867.

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Aft-loaded vane designs can have an impact on surface heat transfer distributions by accelerating boundary layers for a greater portion of the suction surface. New combustion systems developed for low emissions have produced substantial changes to the characteristics of inlet turbulence entering nozzle guide vanes. This paper documents heat transfer rates on an aft-loaded vane subject to turbulence generated by mock combustion configurations representative of recently developed catalytic and dry low NOx (DLN) combustors. Four different inlet turbulence conditions with levels ranging up to 21% are documented in this study and vane heat transfer rates are acquired at vane exit chord Reynolds numbers ranging from 500,000 to 2,000,000. Heat transfer distributions show the influence of the turbulence conditions on heat transfer augmentation and transition. Cascade aerodynamics are well documented and match pressure distributions predicted by a commercial computational fluid dynamics (CFD) code for this large-scale low-speed facility. The aft-loaded vane pressure distribution exhibits a minimum value at about 50% arc on the suction surface. This comprehensive vane heat transfer data set is expected to represent an excellent test case for vane heat transfer predictive methods. Predictive comparisons are shown based on a two-dimensional boundary layer code using an algebraic turbulence model for augmentation as well as a transition model.

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He, H. B., F. F. Duan, and G. C. Li. "Experimental Study on Overall Cooling Effectiveness of Turbine Nozzle Guide Vane with Impingement-Cutback Structure." Journal of Applied Fluid Mechanics 16, no. 2 (February 1, 2023): 223–31. http://dx.doi.org/10.47176/jafm.16.02.1259.

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The overall cooling performance of turbine nozzle guide vane, with the impingement-cutback structure, is experimentally studied in the actual-scale cascade. The gas with the high temperature is used to achieve the actual dynamic viscosity coefficient and the density ratios. The coolant-to-gas mass flow ratio (KG) varies between 0.034 and 0.050 and the gas-to-coolant temperature ratio (KT) varies between 1.5 and 2.4. The local Overall Cooling Effectiveness (OCE) on the middle cross-section of the vane is obtained. The experimental results reveal that the lowest value of the OCE achieves a 10% relative arc length on the suction side of the vane; however, the highest value appears at 40% relative arc length on the pressure side of the vane. The averaged values of the OCE are respectively enhanced by 19.45%, 24.22%, and 35.57% at temperature ratios equal to 1.7, 1.9, and 2.3, with an increase of the KG from 0.034 to 0.050. Added to that, it was identified that an increase of KT from 1.7 to 2.3 leads to the decrease of the OCE. The comparison results show that this characteristic becomes dramatical while KG is 0.034. The higher KT leads to a greater influence of KG, which is illustrated clearly by the compared results of the OCE.

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Gaur, Ritesh, S. Ganesan, and B. V. S. S. S. Prasad. "Comparative Performance of New Surface Roughness Element and Pin fin in Converging Channel for Gas Turbine Application." Defence Science Journal 71, no. 4 (July 1, 2021): 429–35. http://dx.doi.org/10.14429/dsj.71.15394.

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Thermal performance of a novel surface roughness element, named as Double 45 Dimple (D45D), is compared with pin-fin element in a converging channel with rectangular cross section and presented. The Surface Roughness Element (SRE) is derived by combining protrusion & dimple in a particular fashion such that area available for transfer of heat increases. The objective of this study is to demonstrate the applicability of D45D element channel for trailing edge channel of a typical nozzle guide vane where typically pin-fin element is used. New cooling configuration of Nozzle Guide Vane (NGV) with D45D element is also proposed. All thermal and flow related results are derived using validated CFD approach with EARSM turbulence model for a typical value of Reynolds number. From this investigation, it is found that D45D element provides remarkable improvement in the averaged as well as heat transfer in local region for the corresponding surface which makes it a candidate for trailing edge channel cooling application.

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Liu, Zhi Gang, Xiang Jun Fang, Si Yong Liu, Ping Wang, and Zhao Yin. "Research of Aerodynamic Performance of HP-Turbine with Coolant Injections for Variable Cycle Engine." Applied Mechanics and Materials 110-116 (October 2011): 1047–53. http://dx.doi.org/10.4028/www.scientific.net/amm.110-116.1047.

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A highly loaded high-pressure turbine with a supersonic nozzle guide vane and a transonic rotor for a Variable Cycle Engine (VCE) has been investigated. Film cooling strategies were designed for the whole stage, during which the positions, injection orientations and arrangements of cooling holes were confirmed. Three-dimensional steady numerical simulations have been performed in the two operation modes of low and high bypass ratio with different thermodynamic cycle parameters according to the VCE and the coolant injections have been simulated by means of additional source term method. The influences of coolant injections in the fully cooled turbine stage on aerodynamic performance and flow characteristics have been analyzed. The results indicate that, the supersonic nozzle guide vane, over-expansion degree of main flows, fluctuations of static pressure and intensity of corner vortex are lessened or alleviated. In the transonic rotor, expansion and doing work capabilities in the mixed fluid are strengthened. Proper coolants injections are beneficial to the flow characteristics in the blade passage.

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Qiang, Wang, Guo Zhaoyuan, Zhou Chi, Feng Guotai, and Wang Zhongqi. "Coupled Heat Transfer Simulation of a High-pressure Turbine Nozzle Guide Vane." Chinese Journal of Aeronautics 22, no. 3 (June 2009): 230–36. http://dx.doi.org/10.1016/s1000-9361(08)60092-8.

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Piotrowicz, Michal, Pawel Flaszynski, and Piotr Doerffer. "Effect of Hot Spot Location on Flow Structure in Nozzle Guide Vane." Journal of Physics: Conference Series 1101 (October 2018): 012025. http://dx.doi.org/10.1088/1742-6596/1101/1/012025.

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Ames, Forrest E., Chao Wang, and Pierre A. Barbot. "Measurement and Prediction of the Influence of Catalytic and Dry Low NOx Combustor Turbulence on Vane Surface Heat Transfer." Journal of Turbomachinery 125, no. 2 (April 1, 2003): 221–31. http://dx.doi.org/10.1115/1.1559898.

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New combustion systems developed for low emissions have produced substantial changes to the characteristics of inlet turbulence entering nozzle guide vanes. This paper documents the characteristics of turbulence generated by mock combustion system configurations representative of recently developed catalytic and dry low NOx combustors. Additionally, heat transfer rates are determined on the surface of a vane subjected to inlet turbulence generated by these mock combustor configurations. Six different inlet turbulence conditions with levels ranging up to 14% are documented in this study and vane heat transfer rates are acquired at exit chord Reynolds numbers ranging from 500,000 to 2,000,000. Heat transfer distributions show the influence of turbulence level and scale on heat transfer augmentation and transition. Cascade aerodynamics are well documented and match pressure distributions predicted by a commercial CFD code for this large-scale low-speed facility. The vane pressure distribution could be characterized as a conventional or fully loaded distribution. This comprehensive data set is expected to represent an excellent test case for vane heat transfer predictive methods. Predictive comparisons are shown based on a two-dimensional boundary layer code using an algebraic turbulence model for augmentation as well as a transition model.

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Zhang, Yi, Zhu Ma Yu, Xiao Dong Zheng, and Xuan Du. "Optimization Design on Variable Cycle Engine Performance Based on Genetic Algorithm." Advanced Materials Research 940 (June 2014): 120–23. http://dx.doi.org/10.4028/www.scientific.net/amr.940.120.

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The article have described the optimization of the engine performance problem as nonlinear multi-objective programming, and have analyzed the operation principle of the variable cycle engine, made models of maximum thrust , maximum unit thrust, minimum oil consumption, and then adopts the genetic algorithm to solve the model, gained the guide vane angle of CDFS,the guide vane angle of low-pressure.Turbine and the nozzle throat area when the performance is optimal . It is a problem about multi-objective optimization, obtained a series of satisfactory solution and then selected a set of approximate optimal solution as the final argument. Lastly, The matlab software is used to illustrate the effectiveness of the results.

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Jenkins, Sean C., and David G. Bogard. "Scaling of Guide Vane Coolant Profiles and the Reduction of a Simulated Hot Streak." Journal of Turbomachinery 129, no. 3 (August 8, 2006): 619–27. http://dx.doi.org/10.1115/1.2447803.

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The turbine section of a gas turbine engine is subjected to a nonuniform temperature distribution in the gas flow from the combustor. Regions of elevated temperatures, known as “hot streaks,” subject the turbine airfoil to high heat loads. In this study, the reduction of hot streaks by coolant from a film cooled nozzle guide vane was experimentally evaluated. Experiments were conducted with an approach mainstream turbulence level of 20% to simulate actual turbine conditions. The coolant distributions downstream of the vane were measured for varying blowing ratios and varying coolant density, and scaling methods were found for variations in both parameters. For this study, the hot streak peak was positioned to impact the vane at the stagnation line. Measurements of the hot streak strength with coolant blowing showed as much as a 55% decrease in peak temperature compared with no coolant.

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Yang, Dengfeng, Ce Yang, Leon Hu, J. James Yi, Eric Curtis, and Margaret S. Wooldridge. "Numerical investigation of the split sliding guide vane for a variable nozzle turbine." Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 233, no. 8 (April 23, 2018): 2074–84. http://dx.doi.org/10.1177/0954407018768663.

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Jiang, Leiyong, Xijia Wu, and Zhong Zhang. "Conjugate Heat Transfer of an Internally Air-Cooled Nozzle Guide Vane and Shrouds." Advances in Mechanical Engineering 6 (January 1, 2014): 146523. http://dx.doi.org/10.1155/2014/146523.

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In order to assess the life of gas turbine critical components, it is essential to adequately specify their aerothermodynamic working environments. Steady-state analyses of the flow field and conjugate heat transfer of an internally air-cooled nozzle guide vane (NGV) and shrouds of a gas turbine engine at baseline operating conditions are numerically investigated. A high-fidelity CFD model is generated and the simulations are carried out with properly defined boundary conditions. The features of the complicated flow and temperature fields are revealed. In general, the Mach number is lower and the temperature is higher on the NGV pressure side than those on the suction side. There are two high temperature regions on the pressure side, and the temperature across the middle section is relatively low. These findings are closely related to the locations of the holes and outlets of the cooling flow passage, and consistent with the field observations of damaged NGVs. As a technology demonstration, the results provide required information for the life analysis of the NGV/shrouds assembly and improvement of the cooling flow arrangement.

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Robak, Rafał, Mirosław Szczepanik, and Sebastian Rulik. "Parametric Optimization of Nozzle Turbine Vane Modal Characteristics by Means of Artificial System." Applied Sciences 12, no. 19 (September 27, 2022): 9724. http://dx.doi.org/10.3390/app12199724.

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Modal analysis is a fundamental assessment in the design phase of a nozzle guide vane in a low pressure turbine system. Evaluation is crucial for new concept design but also in case of design modification. The technical requirement is to ensure appropriate durability level (number of flight cycles) and the reliability of the system. An understanding of dynamic behavior is one of the key elements in the high cycle fatigue (HCF) evaluation. Finite element method (FEM) analyses are widely used in new product introduction phases to verify modal characteristics with respect to operating range and engine orders (forcing function, excitation). In the process used 2D representation of the nozzle guide vane approximated by axisymmetric and plane stress with thickness FEM plain elements. The optimization process used geometrical parameters (nozzle outer band and casing shell) and surrogate models to find optimal solutions from a frequency placement perspective. A sensitivity analysis and optimization process revealed casing shell thickness to be a major contribution in the modal response and weight. Excluding casing shell parameters led to a lower frequency shift with respect to the reference configuration. The presented optimization framework is very robust and time effective in completing the optimization task together with a sensitivity analysis for the defined design domain. An FEM model validation of the surrogate model showed consistency in the modal analysis results. A promising solution from the component weight standpoint is the optimization with hook position and leaning only. A future research recommendation is to study an extended parameter range to reduce weight impact for this set.

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Povey, T., K. S. Chana, and T. V. Jones. "Heat transfer measurements on an intermediate-pressure nozzle guide vane tested in a rotating annular turbine facility, and the modifying effects of a non-uniform inlet temperature profile." Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy 217, no. 4 (January 1, 2003): 421–31. http://dx.doi.org/10.1243/095765003322315487.

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In modern gas turbine engines there exist significant temperature gradients in the combustor exit flow. These gradients arise because both fuel and dilution air are introduced within the combustor as discrete jets. The effects of this non-uniform temperature field on the aerodynamics and heat transfer rate distributions of nozzle guide vanes and turbine blades is difficult to predict, although an increased understanding of the effects of temperature gradients would enhance the accuracy of estimates of turbine component life and efficiency. Low-frequency measurements of heat transfer rate have been conducted on an annular transonic intermediate-pressure (IP) nozzle guide vane operating downstream of a high-pressure (HP) rotating turbine stage. Measurements were conducted with both uniform and non-uniform inlet temperature profiles. The non-uniform temperature profile included both radial and circumferential gradients of temperature. Experiments were conducted in the isentropic light piston facility at QinetiQ Pyestock, a short-duration engine-size turbine facility with 1.5 turbine stages, in which Mach number, Reynolds number and gas—wall temperature ratios are correctly modelled. Experimental heat transfer results are compared with predictions performed using boundary layer methods.

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Rowbury, D. A., M. L. G. Oldfield, and G. D. Lock. "A Method for Correlating the Influence of External Crossflow on the Discharge Coefficients of Film Cooling Holes." Journal of Turbomachinery 123, no. 2 (February 1, 2000): 258–65. http://dx.doi.org/10.1115/1.1354137.

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An empirical means of predicting the discharge coefficients of film cooling holes in an operating engine has been developed. The method quantifies the influence of the major dimensionless parameters, namely hole geometry, pressure ratio across the hole, coolant Reynolds number, and the freestream Mach number. The method utilizes discharge coefficient data measured on both a first-stage high-pressure nozzle guide vane from a modern aero-engine and a scale (1.4 times) replica of the vane. The vane has over 300 film cooling holes, arranged in 14 rows. Data was collected for both vanes in the absence of external flow. These noncrossflow experiments were conducted in a pressurized vessel in order to cover the wide range of pressure ratios and coolant Reynolds numbers found in the engine. Regrettably, the proprietary nature of the data collected on the engine vane prevents its publication, although its input to the derived correlation is discussed. Experiments were also conducted using the replica vanes in an annular blowdown cascade which models the external flow patterns found in the engine. The coolant system used a heavy foreign gas (SF6 /Ar mixture) at ambient temperatures which allowed the coolant-to-mainstream density ratio and blowing parameters to be matched to engine values. These experiments matched the mainstream Reynolds and Mach numbers and the coolant Mach number to engine values, but the coolant Reynolds number was not engine representative (Rowbury, D. A., Oldfield, M. L. G., and Lock, G. D., 1997, “Engine-Representative Discharge Coefficients Measured in an Annular Nozzle Guide Vane Cascade,” ASME Paper No. 97-GT-99, International Gas Turbine and Aero-Engine Congress & Exhibition, Orlando, Florida, June 1997; Rowbury, D. A., Oldfield, M. L. G., Lock, G. D., and Dancer, S. N., 1998, “Scaling of Film Cooling Discharge Coefficient Measurements to Engine Conditions,” ASME Paper No. 98-GT-79, International Gas Turbine and Aero-Engine Congress & Exhibition, Stockholm, Sweden, June 1998). A correlation for discharge coefficients in the absence of external crossflow has been derived from this data and other published data. An additive loss coefficient method is subsequently applied to the cascade data in order to assess the effect of the external crossflow. The correlation is used successfully to reconstruct the experimental data. It is further validated by successfully predicting data published by other researchers. The work presented is of considerable value to gas turbine design engineers as it provides an improved means of predicting the discharge coefficients of engine film cooling holes.

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Wang, Zhihui, Chaochen Ma, Zhi Huang, Liyong Huang, Xiang Liu, and Zhihong Wang. "A novel variable geometry turbine achieved by elastically restrained nozzle guide vanes." Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 234, no. 9 (April 8, 2020): 2312–29. http://dx.doi.org/10.1177/0954407020909662.

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Variable geometry turbocharging is one of the most significant matching methods between turbocharger and engine, and has been proven to provide air boost for entire engine speed range as well as to reduce turbo-lag. An elastically constrained device designed for a novel variable geometry turbocharger was presented in this paper. The design of the device is based on the nozzle vane’s self-adaptation under interactions of the elastic force by elastically restrained guide vane and the aerodynamic force from flowing gas. The vane rotation mechanism of the novel variable geometry turbocharger is different from regular commercial variable geometry turbocharger systems, which is achieved by an active control system (e.g. actuator). To predict the aerodynamic performance of the novel variable geometry turbocharger, the flow field of the turbine was simulated using transient computational fluid dynamics software combined with a fluid–structure interaction method. The results show that the function of elastically constrained device has similar effectiveness as the traditional variable geometry turbocharger. In addition, the efficiency of the novel variable geometry turbocharger is improved at most operating conditions. Furthermore, a turbocharged diesel engine was created using the AVL BOOST software to evaluate the benefits of the new variable geometry turbocharger. The proposed novel variable geometry turbocharger can effectively improve the engine performance at mid-high speeds, such that the maximum decrease of brake-specific fuel consumption reaches 17.91% under 100% load and 3600 r/min engine condition. However, the engine power and brake-specific fuel consumption decrease significantly at low engine speed conditions, and the decrease is more than 26% under 1000 r/min.

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Watt, R. M., J. L. Allen, N. C. Baines, J. P. Simons, and M. George. "A Study of the Effects of Thermal Barrier Coating Surface Roughness on the Boundary Layer Characteristics of Gas Turbine Aerofoils." Journal of Turbomachinery 110, no. 1 (January 1, 1988): 88–93. http://dx.doi.org/10.1115/1.3262172.

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The effect of thermal barrier coating surface roughness on the aerodynamic performance of gas turbine aerofoils has been investigated for the case of a profile typical of current first-stage nozzle guide vane design. Cascade tests indicate a potential for significant extra loss, depending on Reynolds number, due to thermal barrier coating in its “as-sprayed” state. In this situation polishing coated vanes is shown to be largely effective in restoring their performance. The measurements also suggest a critical low Reynolds number below which the range of roughness tested has no effect on cascade efficiency. Transition detection involved a novel use of thin-film anemometers painted and fired onto the TBC surfaces.

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Dossena, V., A. Perdichizzi, and M. Savini. "The Influence of Endwall Contouring on the Performance of a Turbine Nozzle Guide Vane." Journal of Turbomachinery 121, no. 2 (April 1, 1999): 200–208. http://dx.doi.org/10.1115/1.2841302.

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The paper presents the results of a detailed investigation of the flow field in a gas turbine linear cascade. A comparison between a contoured and a planar configuration of the same cascade has been performed, and differences in the three-dimensional flow field are here analyzed and discussed. The flow evolution downstream of the trailing edge was surveyed by means of probe traversing while a three-dimensional Navier–Stokes solver was employed to obtain information on flow structures inside the vaned passages. The experimental measurements and the numerical simulation of the three-dimensional flow field have been performed for two cascades; one with planar endwalls, and the other with one planar and one profiled endwall, so as to present a reduction of the nozzle height. The investigation was carried out at an isentropic downstream Mach number of 0.6. Airfoils of both cascades were scaled from the same high-pressure gas turbine inlet guide vane. Measurements of the three-dimensional flow field have been performed on five planes downstream of the cascades by means of a miniaturized five-hole pressure probe. The presence of endwall contouring strongly influences the secondary effects; the vortex generation and their development are inhibited by the stronger acceleration taking place throughout the cascade. The results show that the secondary effects on the contoured side of the passage are confined in the endwall region, while on the flat side the secondary vortices display characteristics similar to the ones occurring downstream of the planar cascade. The spanwise outlet angle distribution presents a linear variation for most of the nozzle height, with quite low values approaching the contoured endwall. The analysis of mass-averaged losses shows a significant performance improvement in the contoured cascade. This can be ascribed not only to lower secondary losses but also to a reduction of the profile losses.

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Ceci, Alessandro, Romain Gojon, and Mihai Mihaescu. "Large Eddy Simulations for Indirect Combustion Noise Assessment in a Nozzle Guide Vane Passage." Flow, Turbulence and Combustion 102, no. 2 (August 21, 2018): 299–311. http://dx.doi.org/10.1007/s10494-018-9964-9.

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Zess, G. A., and K. A. Thole. "Computational Design and Experimental Evaluation of Using a Leading Edge Fillet on a Gas Turbine Vane." Journal of Turbomachinery 124, no. 2 (April 1, 2002): 167–75. http://dx.doi.org/10.1115/1.1460914.

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With the desire for increased power output for a gas turbine engine comes the continual push to achieve higher turbine inlet temperatures. Higher temperatures result in large thermal and mechanical stresses particularly along the nozzle guide vane. One critical region along a vane is the leading edge-endwall juncture. Based on the assumption that the approaching flow to this juncture is similar to a two-dimensional boundary layer, previous studies have shown that a horseshoe vortex forms. This vortex forms because of a radial total pressure gradient from the approaching boundary layer. This paper documents the computational design and experimental validation of a fillet placed at the leading edge-endwall juncture of a guide vane to eliminate the horseshoe vortex. The fillet design effectively accelerated the incoming boundary layer thereby mitigating the effect of the total pressure gradient. To verify the CFD studies used to design the leading edge fillet, flowfield measurements were performed in a large-scale, linear, vane cascade. The flowfield measurements were performed with a laser Doppler velocimeter in four planes orientated orthogonal to the vane. Good agreement between the CFD predictions and the experimental measurements verified the effectiveness of the leading edge fillet at eliminating the horseshoe vortex. The flow-field results showed that the turbulent kinetic energy levels were significantly reduced in the endwall region because of the absence of the unsteady horseshoe vortex.

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Wang, Zhihui, Chaochen Ma, Hang Zhang, and Fei Zhu. "A novel pulse-adaption flow control method for a turbocharger turbine: Elastically restrained guide vane." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 234, no. 13 (March 2, 2020): 2581–94. http://dx.doi.org/10.1177/0954406220908623.

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A turbocharger is a key enabler for energy conservation in an internal combustion engine. The turbine in a turbocharger is fed by highly pulsating gas flow due to the reciprocating engine, resulting in significant deterioration of the turbocharger performance. To solve this problem, a novel pulse-optimized regulation mechanism named ‘elastically restrained guide vane’ for a novel variable geometry turbocharger is proposed in this paper. The new mechanism regulates the instantaneous flow angle at turbine inlet due to guide vane's self-adaptive rotation under interactions of the elastic force by elastically restrained guide vane and the aerodynamic force from flowing gas, which is different from the traditional variable geometry turbocharger that is achieved by an active control system (e.g. actuator). To investigate the effectiveness of the novel method, a double-passage computational fluid dynamics model is built in ANSYS CFX software combined with a fluid-structure interaction method. The results demonstrate that the pulse-adaptive regulation method can effectively adjust the nozzle opening according to the different pulsating pressures at turbine inlet. Subsequently, based on the calibrated models, the numerical simulation concentrates on the potential gain in turbine eventual power output and the exhaust energy recover as well as the corresponding effects on efficiency as a result of operating the turbocharger in its elastically restrained guide vane mode compared to its operation as a conventional variable geometry turbocharger.

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,, Rendi, and Budi Hartadi. "PENGARUH PENAMBAHAN NOZZLE GUIDE VANE PADA ROTOR SAVONIUS MODIFIKASI UNTUK TURBIN AIR." AL-JAZARI JURNAL ILMIAH TEKNIK MESIN 3, no. 1 (August 18, 2018). http://dx.doi.org/10.31602/al-jazari.v3i1.1396.

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Indonesia memiliki potensi tenaga air yang cukup besar tetapi belum termanfaatkan secara maksimal. Pengembangan turbin air arus sungai memiliki kendala karena di indonesia kecepatan air sungai relatif lambat. Turbin arus sungai yang cocok di kembangkan untuk aliran lambat adalah turbin air rotor Savonius. Tetapi turbin air rotor Savonus memiliki kinerja yang buruk karena ada beberapa posisi arah angular rotor yang memiliki torsi statik negatif. Untuk meningkatakn kinerja turbin air rotor savonius diusulkan penambahan nozel guide vane. Karena dengan adanya nozel guide vane menunkinkan aliran air sungai dapat diarahkan langsung ke sudu turbin sehingga runer berputar secara maksimal. Dalam kajian ini, analisa dilakukan dengan metode eksperimen dan simulasi, kemudian hasilnya dibandingkan dengan turbin tampa menggunakan nozel guide vane. Koefesien daya dan koefesien torsi di evaluasi pada jumlah sudu 2 sudu 3 dan sudu 4. Dari analisa tersebut diperoleh bahwa rotor savanius dengan penambahan nozel guide vane lebih baik dalam koefesien daya dan koefesien torsi. Koefesien daya tertinggi ada pada rotor dengan jumlah sudu 3 yaitu Cp = 0.39. Pola aliran air di dalam nozel guide pane bervariasi, kecepatan aliran air diluar nozel guide vane lebih cepat dibandingkan di dalam nozel guide vane. Pada sisi cembung sudu terjadi penurunan kecepatan air yang disebabkan terhalangnya arus air oleh nozel guide vane. Distribusi tekanan juga bervariasi dengan adanya nozel guide vane dapat meningkatkan energi tekanan aliran

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Bojdo, Nicholas, Matthew Ellis, Antonio Filippone, Merren Jones, and Alison Pawley. "Particle-Vane Interaction Probability in Gas Turbine Engines." Journal of Turbomachinery 141, no. 9 (June 18, 2019). http://dx.doi.org/10.1115/1.4043953.

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Abstract Engine durability tests are used by manufacturers to demonstrate engine life and minimum performance when subjected to doses of test dusts, often Arizona Road Dust. Grain size distributions are chosen to replicate what enters the engine; less attention is paid to other properties such as composition and shape. We demonstrate here the differences in the probability of interaction of a particle of a given particle Reynolds number on to a vane if particle shape, vane geometry, and flow Reynolds number are varied and discuss why the traditional definition of Stokes number is inadequate for predicting the likelihood of interaction in these flows. We develop a new generalized Stokes number for nozzle guide vanes and demonstrate its use through application to 2D sections of the General Electric E3 nozzle guide vane. The new Stokes number is used to develop a reduced-order probability curve to predict the interaction efficiency of spherical and nonspherical particles, independent of flow conditions and vane geometry. We show that assuming spherical particles instead of more realistic sphericity of 0.75 can lead to as much as 25% difference in the probability of interaction at Stokes numbers of around unity. Finally, we use a hypothetical size distribution to demonstrate the application of the model to predict the total mass fraction of dust interaction with a nozzle guide vane at design point conditions and highlight the potential difference in the accumulation factor between spherical and nonspherical particles.

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Journal articles on the topic 'Nozzle guide vane'

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