Journal articles: 'Computational Combustion'

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Westbrook, Charles K., Yasuhiro Mizobuchi, Thierry J. Poinsot, Phillip J. Smith, and Jürgen Warnatz. "Computational combustion." Proceedings of the Combustion Institute 30, no. 1 (January 2005): 125–57. http://dx.doi.org/10.1016/j.proci.2004.08.275.

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Brookes, S. J., R. S. Cant, I. D. J. Dupere, and A. P. Dowling. "Computational Modeling of Self-Excited Combustion Instabilities." Journal of Engineering for Gas Turbines and Power 123, no. 2 (January 1, 2001): 322–26. http://dx.doi.org/10.1115/1.1362662.

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It is well known that lean premixed combustion systems potentially offer better emissions performance than conventional non-premixed designs. However, premixed combustion systems are more susceptible to combustion instabilities than non-premixed systems. Combustion instabilities (large-scale oscillations in heat release and pressure) have a deleterious effect on equipment, and also tend to decrease combustion efficiency. Designing out combustion instabilities is a difficult process and, particularly if many large-scale experiments are required, also very costly. Computational fluid dynamics (CFD) is now an established design tool in many areas of gas turbine design. However, its accuracy in the prediction of combustion instabilities is not yet proven. Unsteady heat release will generally be coupled to unsteady flow conditions within the combustor. In principle, computational fluid dynamics should be capable of modeling this coupled process. The present work assesses the ability of CFD to model self-excited combustion instabilities occurring within a model combustor. The accuracy of CFD in predicting both the onset and the nature of the instability is reported.

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Chand, Dharmahinder Singh, Daamanjyot Barara, Gautam Ganesh, and Suraj Anand. "Comparison of Efficiency of Conventional Shaped Circular and Elliptical Shaped Combustor." MATEC Web of Conferences 151 (2018): 02002. http://dx.doi.org/10.1051/matecconf/201815102002.

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There have been concerted efforts towards improving the fuel efficiency of the jet engines in the past, with an aim of reducing the incomplete combustion. The process of combustion in a jet engine takes place in the combustor. A study was conducted for enhancement of air-fuel mixing process by computational analysis of an elliptically shaped combustor for a gas turbine engine. The results of computational analysis of an elliptical shape combustor were compared with a circular shape combustor used in gas turbine engines with a identical cross sectional area. The comparison of the computationally derived parameters of the two combustors i.e. temperature, pressure, and velocity are studied and analyzed. The study intends towards the comparison of the combustion efficiencies of the circular and elliptically shaped combustors. The combustion efficency of elliptical chamber is found to be 98.72% at the same time it was observed 56.26% in case of circular type combustor.

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Zhang, Qun, Hua Sheng Xu, Tao Gui, Shun Li Sun, Yue Wu, and Dong Bo Yan. "Investigation on Reaction Flow Field of Low Emission TAPS Combustors." Applied Mechanics and Materials 694 (November 2014): 45–48. http://dx.doi.org/10.4028/www.scientific.net/amm.694.45.

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A twin annular premixing swirler (TAPS) combustor model of low emissions was developed in this study. And computational studies on combustion process in the combustor model were carried out. Standard k-ε Turbulence Model, PDF non-premixed combustion model, Zeldovich thermal NOx formation model and DPM two-phase model were employed. The distributions of some key performance parameters such as gas temperature, flow velocity, concentrations of NOx and CO emissions were obtained and analyzed. At the same time, combustion mechanics inside the TAPS combustor model were investigated. The computational results indicated that the TAPS combustor employed in this study does a better job of improving key combustion performances such as combustion efficiency, total pressure recovery and outlet temperature distribution factor, and reducing NOx and CO emissions at the same time.

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Hendricks, R. C., D. T. Shouse, W. M. Roquemore, D. L. Burrus, B. S. Duncan, R. C. Ryder, A. Brankovic, N. S. Liu, J. R. Gallagher, and J. A. Hendricks. "Experimental and Computational Study of Trapped Vortex Combustor Sector Rig with High-Speed Diffuser Flow." International Journal of Rotating Machinery 7, no. 6 (2001): 375–85. http://dx.doi.org/10.1155/s1023621x0100032x.

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The Trapped Vortex Combustor (TVC) potentially offers numerous operational advantages over current production gas turbine engine combustors. These include lower weight, lower pollutant emissions, effective flame stabilization, high combustion efficiency, excellent high altitude relight capability, and operation in the lean burn or RQL modes of combustion. The present work describes the operational principles of the TVC, and extends diffuser velocities toward choked flow and provides system performance data. Performance data include EINOx results for various fuel-air ratios and combustor residence times, combustion efficiency as a function of combustor residence time, and combustor lean blow-out (LBO) performance. Computational fluid dynamics (CFD) simulations using liquid spray droplet evaporation and combustion modeling are performed and related to flow structures observed in photographs of the combustor. The CFD results are used to understand the aerodynamics and combustion features under different fueling conditions. Performance data acquired to date are favorable compared to conventional gas turbine combustors. Further testing over a wider range of fuel-air ratios, fuel flow splits, and pressure ratios is in progress to explore the TVC performance. In addition, alternate configurations for the upstream pressure feed, including bi-pass diffusion schemes, as well as variations on the fuel injection patterns, are currently in test and evaluation phases.

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Grimm, Felix, Jürgen Dierke, Roland Ewert, Berthold Noll, and Manfred Aigner. "Modelling of combustion acoustics sources and their dynamics in the PRECCINSTA burner test case." International Journal of Spray and Combustion Dynamics 9, no. 4 (July 7, 2017): 330–48. http://dx.doi.org/10.1177/1756827717717390.

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A stochastic, hybrid computational fluid dynamics/computational combustion acoustics approach for combustion noise prediction is applied to the PRECCINSTA laboratory scale combustor (prediction and control of combustion instabilities in industrial gas turbines). The numerical method is validated for its ability to accurately reproduce broadband combustion noise levels from measurements. The approach is based on averaged flow field and turbulence statistics from computational fluid dynamics simulations. The three-dimensional fast random particle method for combustion noise prediction is employed for the modelling of time-resolved dynamics of sound sources and sound propagation via linearised Euler equations. A comprehensive analysis of simulated sound source dynamics is carried out in order to contribute to the understanding of combustion noise formation mechanisms. Therefrom gained knowledge can further on be incorporated for the investigation of onset of thermoacoustic phenomena. The method-inherent stochastic Langevin ansatz for the realisation of turbulence related source decay is analysed in terms of reproduction ability of local one- and two-point statistical input and therefore its applicability to complex test cases. Furthermore, input turbulence statistics are varied, in order to investigate the impact of turbulence on the resulting sound pressure spectra for a swirl stabilised, technically premixed combustor.

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Yuan, Lei, and Chibing Shen. "Computational investigation on combustion instabilities in a rocket combustor." Acta Astronautica 127 (October 2016): 634–43. http://dx.doi.org/10.1016/j.actaastro.2016.06.015.

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Roga, Sukanta, and Krishna Murari Pandey. "Computational Analysis of Hydrogen-Fueled Scramjet Combustor Using Cavities in Tandem Flame Holder." Applied Mechanics and Materials 772 (July 2015): 130–35. http://dx.doi.org/10.4028/www.scientific.net/amm.772.130.

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This work presents the computational analysis of scramjet combustor using cavities in tandem flame holder by means of 3D. The fuel used by scramjet combustor with cavities in tandem flame holder is hydrogen, the fluid flow and the work is based on the species transport combustion with standard k-ε viscous model. The Mach number at inlet is 2.47 and stagnation temperature and static pressure for vitiated air are 1000K and 100kPa respectively. These computational analysis is mainly aimed to study the flow structure and combustion efficiency. The computational results are compared qualitatively and quantitatively with experimental results and these are agreed as well. Due to the combustion, the recirculation region behind the cavity injector becomes larger as compared to mixing case which acts as a flame holder. From the analysis, the maximum Mach number of 2.33 is observed in the recirculation areas.

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Pries, Michael, Andreas Fiolitakis, and Peter Gerlinger. "Numerical Investigation of a High Momentum Jet Flame at Elevated Pressure: A Quantitative Validation with Detailed Experimental Data." Journal of the Global Power and Propulsion Society 4 (December 18, 2020): 264–73. http://dx.doi.org/10.33737/jgpps/130031.

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The development of efficient low emission combustion systems requires methods for an accurate and reliable prediction of combustion processes. Computational Fluid Dynamics (CFD) in combination with combustion modelling is an important tool to achieve this goal. For an accurate computation adequate boundary conditions are crucial. Especially data for the temperature distribution on the walls of the combustion chamber are usually not available. The present work focuses on numerical simulations of a high momentum jet flame in a single nozzle FLOX® type model combustion chamber at elevated pressure. Alongside the balance equations for the fluid the energy equation for the solid combustor walls is solved. To assess the accuracy of this approach, the temperature distribution on the inner combustion chamber wall resulting from this Conjugate Heat Transfer (CHT) simulation is compared to measured wall temperatures. The simulation results within the combustion chamber are compared to detailed experimental data. This includes a comparison of the flow velocities, temperatures as well as species concentrations. To further assess the benefit of including the solid domain in a CFD simulation the results of the CHT simulation are compared to results of a CFD computation where constant temperatures are assumed for all walls of the combustion chamber.

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10

Paul, P. "Computational Fluid Dynamics in Combustion." Defence Science Journal 60, no. 6 (November 20, 2010): 577–82. http://dx.doi.org/10.14429/dsj.60.600.

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P, Karthikeyan, Madhavan S, and Silambarasan SM. "Computational analysis of hydrocarbon combustion." IARJSET 8, no. 5 (May 30, 2021): 506–11. http://dx.doi.org/10.17148/iarjset.2021.8588.

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12

Colantonio, R. O. "The Applicability of Jet-Shear-Layer Mixing and Effervescent Atomization for Low-NOx Combustors." Journal of Engineering for Gas Turbines and Power 120, no. 1 (January 1, 1998): 17–23. http://dx.doi.org/10.1115/1.2818073.

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An investigation has been conducted to develop appropriate technologies for a low-NOx, liquid-fueled combustor. The combustor incorporates an effervescent atomizer used to inject fuel into a premixing duct. Only a fraction of the combustion air is used in the premixing process. This fuel-rich mixture is introduced into the remaining combustion air by a rapid jet-shear-layer mixing process involving radial fuel–air jets impinging on axial air jets in the primary combustion zone. Computational modeling was used as a tool to facilitate a parametric analysis appropriate to the design of an optimum low-NOx combustor. A number of combustor configurations were studied to assess the key combustor technologies and to validate the three-dimensional modeling code. The results from the experimental testing and computational analysis indicate a low-NOx potential for the jet-shear-layer combustor. Key features found to affect NOx emissions are the primary combustion zone fuel–air ratio, the number of axial and radial jets, the aspect ratio and radial location of the axial air jets, and the radial jet inlet hole diameter. Each of these key parameters exhibits a low-NOx point from which an optimized combustor was developed. Also demonstrated was the feasibility of utilizing an effervescent atomizer for combustor application. Further developments in the jet-shear-layer mixing scheme and effervescent atomizer design promise even lower NOx with high combustion efficiency.

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Aithal, S. M. "Charged Species Concentration in Combusting Mixtures Using Equilibrium Chemistry." Journal of Combustion 2018 (October 4, 2018): 1–11. http://dx.doi.org/10.1155/2018/9047698.

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Ionization in flames is of interest in the design and development of modern combustion devices. The identity and concentration of various charged species in reacting mixtures can play an important role in the diagnostics and control of such devices. Simplified chemistry computations that provide good estimates of ionic species in complex flow-fields can be used to model turbulent reacting flows in various combustion devices, greatly reducing the required computational resources for design and development studies. A critical assessment of the use of the equilibrium chemistry method to compute charged species concentration in combusting mixtures under various temperatures, pressures, and thermal disequilibrium conditions is presented. The use of equilibrium chemistry to compute charged species concentrations in propane-air mixtures performed by Calcote and King has been extended. A more accurate computational methodology that includes the effect of negative ions, chemi-ions (H3O+ and CHO+), and thermal nonequilibrium was investigated to evaluate the suitability of equilibrium computations for estimating charged species concentrations in reacting mixtures. The results show that equilibrium computations which include the effects of H3O+ and elevated electron temperatures can indeed explain the levels of ion concentrations observed in laboratory flame experiments under lean and near-stoichiometric conditions. Furthermore, under engine-like conditions at higher temperatures and pressures, equilibrium computations can be used to obtain useful estimates of charged species concentrations in modern combustion devices.

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14

Lv, Tai, and Shi Ze Zhao. "Numerical Simulation Analysis of the Optimized and Transformed 200MW Pulverized Coal Fired Boiler Burner." Applied Mechanics and Materials 672-674 (October 2014): 1524–27. http://dx.doi.org/10.4028/www.scientific.net/amm.672-674.1524.

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With the use of computational fluid mechanics software – FLUENT, the numerical simulation computation of combustion process inside a certain 200MW corner tangential firing boiler whose combustor is transformed by the multi-grade efficient low-nitrogen combustion technology was conducted, thus the furnace temperature, velocity, mixture and NOx concentration field at rated conditions before and after the transformation were obtained. The calculation results were highly identical with the industrial test results. The results show that after using the multi-grade efficient low-nitrogen combustion technology, the NOx emissions significantly lowered down with the drop of about 40% compared with the emissions before transformation, while the furnace coking and high temperature corrosion were effectively controlled, achieving good economic and social benefits and providing a reference to the design and transformation of the same types of boilers.

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Zhou, Lei, Wanhui Zhao, and Haiqiao Wei. "Effect of improved accelerating method on efficient chemistry calculations in diesel engine." International Journal of Engine Research 19, no. 8 (September 18, 2017): 839–53. http://dx.doi.org/10.1177/1468087417731438.

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With detailed chemical kinetics being employed in combustion simulations, its major computational challenge is the time-intensive nature of chemical kinetics integration due to the large number of chemical species and wide range of chemical timescales involved. In this work, an extended tabulated dynamic chemistry approach with dynamic pruning method is carried out to simulate complex spray combustion for non-premixed combustion process. The thought of extended tabulated dynamic chemistry approach with dynamic pruning is achieved by selecting the optimum acceleration method as well as its error tolerances at different combustion stages depending on combustion characteristics involving the low-temperature combustion. The present method is applied to realistically complex combustion systems involving spray flame of n-heptane fuel and non-premixed combustion engine. Computation efficiency of the proposed method is compared with the results using different accelerating methods, including dynamical adaptive chemistry, in situ adaptive tabulation, and coupled method of tabulated dynamical adaptive chemistry. The results show that transient computational cost will decrease for low-temperature combustion by reducing ambient oxygen concentration clearly in spray flame. Meanwhile, very low computational efficiency is presented once the autoignition occurs, especially at the initial oxygen concentration of 21%. Based on the feature, extended tabulated dynamic chemistry approach with dynamic pruning with different dynamic adaptive chemistry error tolerances is proposed to improve computational efficiency. Extended tabulated dynamic chemistry approach with dynamic pruning with larger error tolerance [Formula: see text] improves around two times for decreased amplitude of transient computational cost at high-temperature combustion stage, and at the same time, the computational accuracy is also improved by comparing the important intermediate species obtained by direct integration. For applications in diesel engine, the results show that extended tabulated dynamic chemistry approach with dynamic pruning can accurately capture the first-stage ignition feature that determines the high-temperature combustion stage. In addition, extended tabulated dynamic chemistry approach with dynamic pruning with the smaller in situ adaptive tabulation error tolerance of 0.001 only used at the high-temperature combustion stage significantly improves the performance on diesel engine simulation with a larger chemistry mechanism. The present method further significantly improves computational efficiency with an overall speedup factor of 10 with high-accuracy compared with result using direct integration.

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Ibrahim, S. "COMPUTATIONAL FLUID DYNAMICS AND COMBUSTION MODELLING." International Conference on Applied Mechanics and Mechanical Engineering 18, no. 18 (April 1, 2018): 1. http://dx.doi.org/10.21608/amme.2018.34990.

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Klose, G., R. Schmehl, R. Meier, G. Maier, R. Koch, S. Wittig, M. Hettel, W. Leuckel, and N. Zarzalis. "Evaluation of Advanced Two-Phase Flow and Combustion Models for Predicting Low Emission Combustors." Journal of Engineering for Gas Turbines and Power 123, no. 4 (October 1, 2000): 817–23. http://dx.doi.org/10.1115/1.1377010.

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The development of low-emission aero-engine combustors strongly depends on the availability of accurate and efficient numerical models. The prediction of the interaction between two-phase flow and chemical combustion is one of the major objectives of the simulation of combustor flows. In this paper, predictions of a swirl stabilized model combustor are compared to experimental data. The computational method is based on an Eulerian two-phase model in conjunction with an eddy dissipation (ED) and a presumed-shape-PDF (JPDF) combustion model. The combination of an Eulerian two-phase model with a JPDF combustion model is a novelty. It was found to give good agreement to the experimental data.

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Pang, Yik Siang, Woon Phui Law, Kang Qin Pung, and Jolius Gimbun. "A Computational Fluid Dynamics Study of Turbulence, Radiation, and Combustion Models for Natural Gas Combustion Burner." Bulletin of Chemical Reaction Engineering & Catalysis 13, no. 1 (April 2, 2018): 155. http://dx.doi.org/10.9767/bcrec.13.1.1395.155-169.

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This paper presents a Computational Fluid Dynamics (CFD) study of a natural gas combustion burner focusing on the effect of combustion, thermal radiation and turbulence models on the temperature and chemical species concentration fields. The combustion was modelled using the finite rate/eddy dissipation (FR/EDM) and partially premixed flame models. Detailed chemistry kinetics CHEMKIN GRI-MECH 3.0 consisting of 325 reactions was employed to model the methane combustion. Discrete ordinates (DO) and spherical harmonics (P1) model were employed to predict the thermal radiation. The gas absorption coefficient dependence on the wavelength is resolved by the weighted-sum-of-gray-gases model (WSGGM). Turbulence flow was simulated using Reynolds-averaged Navier-Stokes (RANS) based models. The findings showed that a combination of partially premixed flame, P1 and standard k-ε (SKE) gave the most accurate prediction with an average deviation of around 7.8% of combustion temperature and 15.5% for reactant composition (methane and oxygen). The results show the multi-step chemistry in the partially premixed model is more accurate than the two-step FR/EDM. Meanwhile, inclusion of thermal radiation has a minor effect on the heat transfer and species concentration. SKE turbulence model yielded better prediction compared to the realizable k-ε (RKE) and renormalized k-ε (RNG). The CFD simulation presented in this work may serve as a useful tool to evaluate a performance of a natural gas combustor. Copyright © 2018 BCREC Group. All rights reservedReceived: 26th July 2017; Revised: 9th October 2017; Accepted: 30th October 2017; Available online: 22nd January 2018; Published regularly: 2nd April 2018How to Cite: Pang, Y.S., Law, W.P., Pung, K.Q., Gimbun, J. (2018). A Computational Fluid Dynamics Study of Turbulence, Radiation, and Combustion Models for Natural Gas Combustion Burner. Bulletin of Chemical Reaction Engineering & Catalysis, 13 (1): 155-169 (doi:10.9767/bcrec.13.1.1395.155-169)

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Serbin, Sergey. "THERMO ACOUSTIC PROCESSES IN LOW EMISSION COMBUSTION CHAMBER OF GAS TURBINE ENGINE CAPACITY 25 MW." Science Journal Innovation Technologies Transfer, no. 2019-2 (May 5, 2019): 86–90. http://dx.doi.org/10.36381/iamsti.2.2019.86-90.

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The appliance of modern tools of the computational fluid dynamics for the investigation of the pulsation processes in the combustion chamber caused by the design features of flame tubes and aerodynamic interaction compressor, combustor and turbine is discussed. The aim of the research is to investigate and forecast the non-stationary processes in the gas turbine combustion chambers. The results of the numerical experiments which were carried out using three-dimensional mathematical models in gaseous fuels combustion chambers reflect sufficiently the physical and chemical processes of the unsteady combustion and can be recommended to optimize the geometrical and operational parameters of the low-emission combustion chamber. The appliance of such mathematical models are reasonable for the development of new samples of combustors which operate at the lean air-fuel mixture as well as for the modernization of the existing chambers with the aim to develop the constructive measures aimed at reducing the probability of the occurrence of the pulsation combustion modes. Keywords: gas turbine engine, combustor, turbulent combustion, pulsation combustion, numerical methods, mathematical simulation.

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Karki, K. C., V. L. Oechsle, and H. C. Mongia. "A Computational Procedure for Diffuser-Combustor Flow Interaction Analysis." Journal of Engineering for Gas Turbines and Power 114, no. 1 (January 1, 1992): 1–7. http://dx.doi.org/10.1115/1.2906301.

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This paper describes a diffuser-combustor flow interaction analysis procedure for gas turbine combustion systems. The method is based on the solution of the Navier–Stokes equations in a generalized nonorthogonal coordinate system. The turbulence effects are modeled via the standard two-equation (k-ε) model. The method has been applied to a practical gas turbine combustor-diffuser system that includes support struts and fuel nozzles. Results have been presented for a three-dimensional simulation, as well as for a simplified axisymmetric simulation. The flow exhibits significant three-dimensional behavior. The axisymmetric simulation is shown to predict the static pressure recovery and the total pressure losses reasonably well.

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21

James, S., M. S. Anand, M. K. Razdan, and S. B. Pope. "In Situ Detailed Chemistry Calculations in Combustor Flow Analyses." Journal of Engineering for Gas Turbines and Power 123, no. 4 (March 1, 1999): 747–56. http://dx.doi.org/10.1115/1.1384878.

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In the numerical simulation of turbulent reacting flows, the high computational cost of integrating the reaction equations precludes the inclusion of detailed chemistry schemes, therefore reduced reaction mechanisms have been the more popular route for describing combustion chemistry, albeit at the loss of generality. The in situ adaptive tabulation scheme (ISAT) has significantly alleviated this problem by facilitating the efficient integration of the reaction equations via a unique combination of direct integration and dynamic creation of a look-up table, thus allowing for the implementation of detailed chemistry schemes in turbulent reacting flow calculations. In the present paper, the probability density function (PDF) method for turbulent combustion modeling is combined with the ISAT in a combustor design system, and calculations of a piloted jet diffusion flame and a low-emissions premixed gas turbine combustor are performed. It is demonstrated that the results are in good agreement with experimental data and computations of practical turbulent reacting flows with detailed chemistry schemes are affordable.

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Vermes, G., L. E. Barta, and J. M. Bee´r. "Low NOx Emission From an Ambient Pressure Diffusion Flame Fired Gas Turbine Cycle (APGC)." Journal of Engineering for Gas Turbines and Power 125, no. 1 (December 27, 2002): 46–50. http://dx.doi.org/10.1115/1.1520160.

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The prospects of reduced NOx emission, improved efficiency, stable, and oscillation-free combustion, and reduced construction costs achieved by an “Inverted Brayton Cycle” applied to midsize (0.5 to 5.0 MWe) power plants are discussed. In this cycle, the combustion products of an atmospheric pressure combustor are expanded in the gas turbine to subatmospheric pressure and following heat extraction are compressed back to slightly above the atmospheric, sufficient to enable a controlled fraction of the exhaust gas to be recirculated to the combustor. Due to the larger volume flow rate of the gas, the polytropic efficiency of both the turbine and compressor of this small machine is increased. Because of the low operating pressure and flue gas recirculation, both of which are instrumental to low NOx formation, the combustor can be operated in the diffusion flame mode; this, on the other hand, assures good flame stability and oscillation-free combustion over wide ranges of the operating variables. For the task of obtaining very low NOx formation, the well-tested multi annular swirl burner (MASB) is chosen. Recent computational and experimental development of the MASB by Siemens-Westinghouse as a topping combustor is discussed. It is shown that the MASB operated in rich-quench-lean mode is capable of single-digit NOx emission. The emissions are further lowered in the APGC by ambient pressure combustion, and by the injection of the recirculated gas in the quench zone of the combustor. Results of a computational optimization study of the ambient pressure gas turbine cycle (APGC) are presented.

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Deng, Xiaowen, Li Xing, Hong Yin, Feng Tian, and Qun Zhang. "Numerical Investigation of Fuel Distribution Effect on Flow and Temperature Field in a Heavy Duty Gas Turbine Combustor." International Journal of Turbo & Jet-Engines 35, no. 1 (March 26, 2018): 71–80. http://dx.doi.org/10.1515/tjj-2016-0021.

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AbstractMultiple-swirlers structure is commonly adopted for combustion design strategy in heavy duty gas turbine. The multiple-swirlers structure might shorten the flame brush length and reduce emissions. In engineering application, small amount of gas fuel is distributed for non-premixed combustion as a pilot flame while most fuel is supplied to main burner for premixed combustion. The effect of fuel distribution on the flow and temperature field related to the combustor performance is a significant issue. This paper investigates the fuel distribution effect on the combustor performance by adjusting the pilot/main burner fuel percentage. Five pilot fuel distribution schemes are considered including 3 %, 5 %, 7 %, 10 % and 13 %. Altogether five pilot fuel distribution schemes are computed and deliberately examined. The flow field and temperature field are compared, especially on the multiple-swirlers flow field. Computational results show that there is the optimum value for the base load of combustion condition. The pilot fuel percentage curve is calculated to optimize the combustion operation. Under the combustor structure and fuel distribution scheme, the combustion achieves high efficiency with acceptable OTDF and low NOXemission. Besides, the CO emission is also presented.

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Costura, D. M., P. B. Lawless, and S. H. Fankel. "A Computational Model for the Study of Gas Turbine Combustor Dynamics." Journal of Engineering for Gas Turbines and Power 121, no. 2 (April 1, 1999): 243–48. http://dx.doi.org/10.1115/1.2817112.

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A dynamic combustor model is developed for inclusion into a one-dimensional full gas turbine engine simulation code. A flux-difference splitting algorithm is used to numerically integrate the quasi-one-dimensional Euler equations, supplemented with species mass conservation equations. The combustion model involves a single-step, global finite-rate chemistry scheme with a temperature-dependent activation energy. Source terms are used to account for mass bleed and mass injection, with additional capabilities to handle momentum and energy sources and sinks. Numerical results for cold and reacting flow for a can-type gas turbine combustor are presented. Comparisons with experimental data from this combustor are also made.

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Dinesh, K. K. J. Ranga, M. P. Kirkpatrick, and A. Odedra. "COMPUTATIONAL FLUID DYNAMICS MODELING TOWARD CLEAN COMBUSTION." Computational Thermal Sciences 4, no. 1 (2012): 49–65. http://dx.doi.org/10.1615/computthermalscien.2012004160.

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Novozhilov, V., B. Moghtaderi, D. F. Fletcher, and J. H. Kent. "Computational fluid dynamics modelling of wood combustion." Fire Safety Journal 27, no. 1 (July 1996): 69–84. http://dx.doi.org/10.1016/s0379-7112(96)00022-7.

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Pope, Stephen B., and Zhuyin Ren. "Efficient Implementation of Chemistry in Computational Combustion." Flow, Turbulence and Combustion 82, no. 4 (April 2, 2008): 437–53. http://dx.doi.org/10.1007/s10494-008-9145-3.

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Jarrahbashi, Dorrin, Sayop Kim, Benjamin W. Knox, and Caroline L. Genzale. "Computational analysis of end-of-injection transients and combustion recession." International Journal of Engine Research 18, no. 10 (April 5, 2017): 1088–110. http://dx.doi.org/10.1177/1468087417701280.

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Mixing and combustion of engine combustion network Spray A after end of injection are modeled using highly resolved multidimensional numerical simulations to explore the physics underlying recent experimental observations of combustion recession. Reacting spray simulations are performed using a traditional Lagrangian–Eulerian coupled formulation for two-phase mixture transport with a Reynolds-averaged Navier–Stokes approach using the open-source computational fluid dynamics code OpenFOAM. Chemical kinetics models for n-dodecane by Cai et al. and Yao et al. are deployed to evaluate the impact of mechanism formulation and low-temperature chemistry on predictions of combustion recession behavior. Simulations with the Cai mechanism show that under standard Spray A conditions, the end-of-injection transient induces second-stage ignition in distinct regions near the nozzle that are initially spatially separated from the lifted diffusion flame, but then rapidly merge with flame. By contrast, the Yao mechanism fails to predict sufficient low-temperature chemistry in mixtures upstream of the diffusion flame during the end-of-injection transient and does not predict combustion recession for the same conditions. The effects of the shape and duration of the end-of-injection transient on the entrainment wave near the nozzle, the likelihood of combustion recession, and the spatiotemporal development of mixing and chemistry in near-nozzle mixtures are also investigated. With a more rapid ramp-down injection profile (ramp-down duration < 400 µs), a weaker combustion recession occurs earlier in time after the start of ramp-down. For extremely fast ramp-down (ramp-down duration = 0), the entrainment flux varies rapidly near the nozzle and over-leaning of the mixture completely suppresses combustion recession. For a slower ramp-down profile with respect to the standard Spray A condition, complete combustion recession back toward the nozzle is observed and combustion recession occurred later in time. Simulations qualitatively agreed with the past experimental and modeling observations of combustion recession with different end-of-injection transients.

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Zian, Norhaslina Mat, Hasril Hasini, and Nur Irmawati Om. "Investigation of Syngas Combustion at Variable Methane Composition in Can Combustor Using CFD." Advanced Materials Research 1016 (August 2014): 592–96. http://dx.doi.org/10.4028/www.scientific.net/amr.1016.592.

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This paper describes the analysis of the fundamental effect of synthetic gas combustion in a can-type combustor using Computational Fluid Dynamic(CFD). Emphasis is given towards the effect of variation of methane to the flame profile, temperature distribution and heat flux in the combustor. In this study, the composition of hydrogen in the syngas was fixed at 30% while methane and carbon monoxide were varied. Results show that the flame temperature and NOxemissions are highly dependent on the composition of methane in the syngas fuel. Nevertheless, the overall NOxemission for all cases is relatively lower than the conventional pure natural gas combustion.

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Zhang, Y. G., Y. G. Bai, X. C. Yu, and Y. F. Liu. "Numerical Analysis of Active Cooling Structure of Engine Combustion Chamber." Advanced Materials Research 629 (December 2012): 564–69. http://dx.doi.org/10.4028/www.scientific.net/amr.629.564.

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With the convective heat transfer theory, numerical analysis of fluid-solid-heat coupling is implemented for the engine combustion chamber cooling structure based on finite element method and computational fluid dynamic method, thus to obtain valuable simulation results. Different components of the mesh generation method used which have different influences on the computational results are thought over during this analysis process, including different grid type, grid density and boundary layer meshes. Moreover, MPI parallel technique is also used to resolve the computation demands. The temperature distributions of the key parts in the cooling structure are investigated, which can be used as a significant reference for the thermal protection design of the engine combustion chamber.

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Pekkan, K., and M. R. Nalim. "Two-Dimensional Flow and NOx Emissions in Deflagrative Internal Combustion Wave Rotor Configurations." Journal of Engineering for Gas Turbines and Power 125, no. 3 (July 1, 2003): 720–33. http://dx.doi.org/10.1115/1.1586315.

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A wave rotor is proposed for use as a constant volume combustor. A novel design feature is investigated as a remedy for hot gas leakage, premature ignition, and pollutant emissions that are possible in this class of unsteady machines. The base geometry involves fuel injection partitions that allow stratification of fuel/oxidizer mixtures in the wave rotor channel radially, enabling pilot ignition of overall lean mixture for low NOx combustion. In this study, available turbulent combustion models are applied to simulate approximately constant volume combustion of propane and resulting transient compressible flow. Thermal NO production histories are predicted by simulations of the STAR-CD code. Passage inlet/outlet/wall boundary conditions are time-dependent, enabling the representation of a typical deflagrative internal combustor wave rotor cycle. Some practical design improvements are anticipated from the computational results. For a large number of derivative design configurations, fuel burn rate, two-dimensional flow and emission levels are evaluated. The sensitivity of channel combustion to initial turbulence levels is evaluated.

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YAN, Y. W., Y. P. Liu, Y. C. Liu, and J. H. Li. "Experimental and computational investigations of flow dynamics in LPP combustor." Aeronautical Journal 121, no. 1240 (May 31, 2017): 790–802. http://dx.doi.org/10.1017/aer.2017.31.

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ABSTRACTA Lean Premixed Prevaporised (LPP) low-emission combustor with a staged lean combustion technology was developed. In order to study cold-flow dynamics in the LPP combustor, both experimental tests using the particle image velocimetry (PIV) to quantify the flow dynamics and numerical simulation using the commercial software (FLUENT) were conducted, respectively. Numerical results were in good agreement with the experimental data. It is shown from the observation of the results that: there is a Primary Recirculation Zone (PRZ), a Corner Recirculation Zone (CRZ) and a Lip Recirculation Zone (LRZ) in the LPP combustor, and the exchanges of mass, momentum and energy between pilot swirling flow and primary swirling flow are contributed by the velocity gradients, and the shear flow is transformed into a mixing layer exhibiting the higher Reynolds stresses, which suggests the mixing process is strictly affected by the Reynolds stresses.

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Andreini, A., C. Bianchini, and A. Innocenti. "Large Eddy Simulation of a Bluff Body Stabilized Lean Premixed Flame." Journal of Combustion 2014 (2014): 1–18. http://dx.doi.org/10.1155/2014/710254.

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The present study is devoted to verify current capabilities of Large Eddy Simulation (LES) methodology in the modeling of lean premixed flames in the typical turbulent combustion regime of Dry LowNOxgas turbine combustors. A relatively simple reactive test case, presenting all main aspects of turbulent combustion interaction and flame stabilization of gas turbine lean premixed combustors, was chosen as an affordable test to evaluate the feasibility of the technique also in more complex test cases. A comparison between LES and RANS modeling approach is performed in order to discuss modeling requirements, possible gains, and computational overloads associated with the former. Such comparison comprehends a sensitivity study to mesh refinement and combustion model characteristic constants, computational costs, and robustness of the approach. In order to expand the overview on different methods simulations were performed with both commercial and open-source codes switching from quasi-2D to fully 3D computations.

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McGuirk, J. J. "The aerodynamic challenges of aeroengine gas-turbine combustion systems." Aeronautical Journal 118, no. 1204 (June 2014): 557–99. http://dx.doi.org/10.1017/s0001924000009386.

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Abstract The components of an aeroengine gas-turbine combustor have to perform multiple tasks – control of external and internal air distribution, fuel injector feed, fuel/air atomisation, evaporation, and mixing, flame stabilisation, wall cooling, etc. The ‘rich-burn’ concept has achieved great success in optimising combustion efficiency, combustor life, and operational stability over the whole engine cycle. This paper first illustrates the crucial role of aerodynamic processes in achieving these performance goals. Next, the extra aerodynamic challenges of the ‘lean-burn’ injectors required to meet the ever more stringent NO x emissions regulations are introduced, demonstrating that a new multi-disciplinary and ‘whole system’ approach is required. For example, high swirl causes complex unsteady injector aerodynamics; the threat of thermo-acoustic instabilities means both aerodynamic and aeroacoustic characteristics of injectors and other air admission features must be considered; and high injector mass flow means potentially strong compressor/combustor and combustor/turbine coupling. The paper illustrates how research at Loughborough University, based on complementary use of advanced experimental and computational methods, and applied to both isolated sub-components and fully annular combustion systems, has improved understanding and identified novel ideas for combustion system design.

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Dawwa, Mahran. "Simulation of Combustion Process in Diesel Engines Based on Eddy Dissipation Model." Applied Mechanics and Materials 823 (January 2016): 315–18. http://dx.doi.org/10.4028/www.scientific.net/amm.823.315.

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The aim of this study is to simulate the combustion process in the combustion chamber of diesel engines by using eddy dissipation model (EDM) and computational fluid dynamics method (CFD). Computational fluid dynamics has been used wieldy in the recent years for simulating the strokes of diesel engines including the combustion process. Eddy dissipation model can be used for simulating non-premixed combustion cases such as the combustion in diesel engines. The simulation steps and the simulation results will be discussed and illustrated. ANSYS program is the software which used for performing this simulation.

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Stitzel, Sarah, and Karen A. Thole. "Flow Field Computations of Combustor-Turbine Interactions Relevant to a Gas Turbine Engine." Journal of Turbomachinery 126, no. 1 (January 1, 2004): 122–29. http://dx.doi.org/10.1115/1.1625691.

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The current demands for high-performance gas turbine engines can be reached by raising combustion temperatures to increase power output. High combustion temperatures create a harsh environment that leads to the consideration of the durability of the combustor and turbine sections. This paper presents a computational study of a flow field that is representative of what occurs in a combustor and how that flow field convects through the first downstream stator vane. The results of this study indicate that the development of the secondary flow field in the turbine is highly dependent on the incoming total pressure profile. The endwall heat transfer is also found to depend strongly on the secondary flow field.

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Debnath, Pinku, and KM Pandey. "Exergetic efficiency analysis of hydrogen–air detonation in pulse detonation combustor using computational fluid dynamics." International Journal of Spray and Combustion Dynamics 9, no. 1 (June 22, 2016): 44–54. http://dx.doi.org/10.1177/1756827716653344.

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Exergy losses during the combustion process, heat transfer, and fuel utilization play a vital role in the analysis of the exergetic efficiency of combustion process. Detonation is thermodynamically more efficient than deflagration mode of combustion. Detonation combustion technology inside the pulse detonation engine using hydrogen as a fuel is energetic propulsion system for next generation. In this study, the main objective of this work is to quantify the exergetic efficiency of hydrogen–air combustion for deflagration and detonation combustion process. Further detonation parameters are calculated using 0.25, 0.35, and 0.55 of [Formula: see text] mass concentrations in the combustion process. The simulations have been performed for converging the solution using commercial computational fluid dynamics package Ansys Fluent solver. The details of combustion physics in chemical reacting flows of hydrogen–air mixture in two control volumes were simulated using species transport model with eddy dissipation turbulence chemistry interaction. From these simulations it was observed that exergy loss in the deflagration combustion process is higher in comparison to the detonation combustion process. The major observation was that pilot fuel economy for the two combustion processes and augmentation of exergetic efficiencies are better in the detonation combustion process. The maximum exergetic efficiency of 55.12%, 53.19%, and 23.43% from deflagration combustion process and from detonation combustion process, 67.55%, 57.49%, and 24.89%, are obtained from aforesaid [Formula: see text] mass fraction. It was also found that for lesser fuel mass fraction higher exergetic efficiency was observed.

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Rozainee, M., S. P. Ngo, Arshad A. Salema, and K. G. Tan. "Computational fluid dynamics modeling of rice husk combustion in a fluidised bed combustor." Powder Technology 203, no. 2 (November 2010): 331–47. http://dx.doi.org/10.1016/j.powtec.2010.05.026.

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Trevisan, B. P., and W. M. C. Dourado. "EXPERIMENTAL STUDY OF THE INLET FLOW IN A NON-PREMIXED COMBUSTION CHAMBER." Revista de Engenharia Térmica 19, no. 1 (September 9, 2020): 72. http://dx.doi.org/10.5380/reterm.v19i1.76437.

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The evaluation, validation and development of the models used in computation fluid dynamics requires the availability of experimental data for which the boundary conditions, especially the conditions of the inlet flow, are well defined. Laser diagnostics techniques provide experimental data used in computational fluid dynamics and are a powerful tool for measurements of the mean properties and fluctuations of the turbulent flow because they are non-intrusive methods, with high repetition rate and high spatial and temporal resolution. Therefore, in the present work an experimental study of the inlet flow (inert and combusting flows) in a non-premixed combustion chamber is presented. The velocity measurements were carried out using a laser Doppler velocimeter at the entrance region of the combustion chamber. An asymmetry on the mean flow and an increase on the total velocity fluctuations with the increase of the equivalence ratio was observed. The major effect on the increase of the equivalence ratio was a presence of a coherent movement on large scales associated to the flame brush dynamics.

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Lee, Sang-Hyeon, In-Seuck Jeung, and Youngbin Yoon. "Computational Investigation of Shock-Enhanced Mixing and Combustion." AIAA Journal 35, no. 12 (December 1997): 1813–20. http://dx.doi.org/10.2514/2.56.

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Laevsky, Yu M., and T. A. Nosova. "A multidimensional computational model of filtration gas combustion." Sibirskii zhurnal industrial'noi matematiki 23, no. 1 (March 6, 2020): 126–42. http://dx.doi.org/10.33048/sibjim.2020.23.111.

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Delprete, Cristiana, Fabio Pregno, and Carlo Rosso. "Internal Combustion Engine Design: a Practical Computational Methodology." SAE International Journal of Engines 2, no. 1 (April 20, 2009): 263–70. http://dx.doi.org/10.4271/2009-01-0477.

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Laevsky, Yu M., and T. A. Nosova. "A Multidimensional Computational Model of Filtration Gas Combustion." Journal of Applied and Industrial Mathematics 14, no. 1 (January 2020): 148–61. http://dx.doi.org/10.1134/s1990478920010147.

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Lee, Sang-Hyeon, In-Seuck Jeung, and Youngbin Yoon. "Computational investigation of shock-enhanced mixing and combustion." AIAA Journal 35 (January 1997): 1813–20. http://dx.doi.org/10.2514/3.13756.

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Prosser, R., and R. S. Cant. "On the Use of Wavelets in Computational Combustion." Journal of Computational Physics 147, no. 2 (December 1998): 337–61. http://dx.doi.org/10.1006/jcph.1998.6092.

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Bi, Xiaojie, Maoyu Xiao, Xinqi Qiao, Chia-Fon Lee, and Liu Yu. "Experimental and computational investigation of temperature effects on soot mechanisms." Journal of the Serbian Chemical Society 79, no. 7 (2014): 881–95. http://dx.doi.org/10.2298/jsc130614125b.

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Effects of initial ambient temperatures on combustion and soot emission characteristics of diesel fuel were investigated through experiment conducted in optical constant volume chamber and simulation using phenomenological soot model. There are four difference initial ambient temperatures adopted in our research: 1000 K, 900 K, 800 K and 700 K. In order to obtain a better prediction of soot behavior, phenomenological soot model was revised to take into account the soot oxidation feedback on soot number density and good agreement was observed in the comparison of soot measurement and prediction. Results indicated that ignition delay prolonged with the decrease of initial ambient temperature. The heat release rate demonstrated the transition from mixing controlled combustion at high ambient temperature to premixed combustion mode at low ambient temperature. At lower ambient temperature, soot formation and oxidation mechanism were both suppressed. But finally soot mass concentration reduced with decreasing initial ambient temperature. Although the drop in ambient temperature did not cool the mean in-cylinder temperature during the combustion, it did shrink the total area of local high equivalence ratio, in which soot usually generated fast. At 700 K initial ambient temperature, soot emissions were almost negligible, which indicates that sootless combustion might be achieved at super low initial temperature operation conditions.

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Ganji, Prabhakara, Rajesh Raju, and Srinivasa Rao. "Computational optimization of biodiesel combustion using response surface methodology." Thermal Science 21, no. 1 Part B (2017): 465–73. http://dx.doi.org/10.2298/tsci161229031g.

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The present work focuses on optimization of biodiesel combustion phenomena through parametric approach using response surface methodology. Physical properties of biodiesel play a vital role for accurate simulations of the fuel spray, atomization, combustion, and emission formation processes. Typically methyl based biodiesel consists of five main types of esters: methyl palmitate, methyl oleate, methyl stearate, methyl linoleate, and methyl linolenate in its composition. Based on the amount of methyl esters present the properties of pongamia bio-diesel and its blends were estimated. CONVERGETM computational fluid dynamics software was used to simulate the fuel spray, turbulence and combustion phenomena. The simulation responses such as indicated specific fuel consumption, NOx, and soot were analyzed using design of experiments. Regression equations were developed for each of these responses. The optimum parameters were found out to be compression ratio ? 16.75, start of injection ? 21.9? before top dead center, and exhaust gas re-circulation ? 10.94%. Results have been compared with baseline case.

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Zhukov, Victor P. "Verification, Validation, and Testing of Kinetic Mechanisms of Hydrogen Combustion in Fluid-Dynamic Computations." ISRN Mechanical Engineering 2012 (August 13, 2012): 1–11. http://dx.doi.org/10.5402/2012/475607.

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A one-step, a two-step, an abridged, a skeletal, and four detailed kinetic schemes of hydrogen oxidation have been tested. A new skeletal kinetic scheme of hydrogen oxidation has been developed. The CFD calculations were carried out using ANSYS CFX software. Ignition delay times and speeds of flames were derived from the computational results. The computational data obtained using ANSYS CFX and CHEMKIN, and experimental data were compared. The precision, reliability, and range of validity of the kinetic schemes in CFD simulations were estimated. The impact of kinetic scheme on the results of computations was discussed. The relationship between grid spacing, time step, accuracy, and computational cost was analyzed.

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Sharma, N. Y., and S. K. Som. "Influence of fuel volatility on combustion and emission characteristics in a gas turbine combustor at different inlet pressures and swirl conditions." Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy 216, no. 3 (May 1, 2002): 257–68. http://dx.doi.org/10.1243/095765002320183577.

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The practical challenges in research in the field of gas turbine combustion mainly centre around a clean emission, a low liner wall temperature and a desirable exit temperature distribution for turboma-chinery applications, along with fuel economy of the combustion process. An attempt has been made in the present paper to develop a computational model based on stochastic separated flow analysis of typical diffusion-controlled spray combustion of liquid fuel in a gas turbine combustor to study the influence of fuel volatility at different combustor pressures and inlet swirls on combustion and emission characteristics. A κ-ɛ model with wall function treatment for the near-wall region has been adopted for the solution of conservation equations in gas phase. The initial spray parameters are specified by a suitable probability distribution function (PDF) size distribution and a given spray cone angle. A radiation model for the gas phase, based on the first-order moment method, has been adopted in consideration of the gas phase as a grey absorbing-emitting medium. The formation of thermal NO x as a post-combustion reaction process is determined from the Zeldovich mechanism. It has been recognized from the present work that an increase in fuel volatility increases combustion efficiency only at higher pressures. For a given fuel, an increase in combustor pressure, at a constant inlet temperature, always reduces the combustion efficiency, while the influence of inlet swirl is found to decrease the combustion efficiency only at higher pressure. The influence of inlet pressure on pattern factor is contrasting in nature for fuels with lower and higher volatilities. For a higher-volatility fuel, a reduction in inlet pressure decreases the value of the pattern factor, while the trend is exactly the opposite in the case of fuels with lower volatilities. The NOx emission level increases with decrease in fuel volatility at all combustor pressures and inlet swirls. For a given fuel, the NOx emission level decreases with a reduction in combustor pressure and an increase in inlet swirl number.

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Reale, Fabrizio, Raffaela Calabria, Fabio Chiariello, Rocco Pagliara, and Patrizio Massoli. "A Micro Gas Turbine Fuelled by Methane-Hydrogen Blends." Applied Mechanics and Materials 232 (November 2012): 792–96. http://dx.doi.org/10.4028/www.scientific.net/amm.232.792.

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The combustion efficiency and the gaseous emission of a 100 kWe MGT, designed for working with natural gas but fuelled with blends containing up to 10% of hydrogen is investigated. A critical comparison between experimental data and results of the CFD analysis of the combustor is discussed. The k-epsilon RANS turbulence model and the Finite Rate – Eddy Dissipation combustion model were used in the numerical computations. The chemical kinetic mechanisms embedded were the 2-step Westbrook and Dryer for methane oxidation, 1-step Westbrook and Dryer for hydrogen oxidation and the Zeldovich mechanism for NO formation. The experimental data and numerical computations are in agreement within the experimental accuracy for NO emissions. Regarding CO, there is a significant deviation between experimental and computational data due to the scarce predictive capability of the simple two steps kinetic mechanism was adopted. From a practical point of view, the possibility of using fuels with a similar Wobbe index was confirmed. In particular the addiction of 10 % of hydrogen to pure methane doesn’t affect the behavior of the micro gas turbine either in terms of NO or CO emissions.

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Journal articles on the topic 'Computational Combustion'

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