Academic literature on the topic 'Turbocharger with variable geometry vanes'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Turbocharger with variable geometry vanes.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Journal articles on the topic "Turbocharger with variable geometry vanes"
1
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.
Full textAbstract:
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.
2
Jiang, P. M., and A. Whitfield. "Investigation of Vaned Diffusers as a Variable Geometry Device for Application to Turbocharger Compressors." Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 206, no. 3 (July 1992): 209–20. http://dx.doi.org/10.1243/pime_proc_1992_206_179_02.
Full textAbstract:
The potential of guide vanes as a variable geometry device, placed in the conventional vaneless diffuser, to extend the operating range of a turbocharger compressor is investigated. Vaned diffusers are not normally employed in turbocharger applications as the consequent reduction in operating range is more damaging than the beneficial improvement in peak efficiency and pressure ratio. The variable geometry concept considered here is primarily one in which the guide vanes are introduced at the near surge flow conditions. The leading edge vane angle is set to accept the highly tangential flow at the near surge conditions, and the vane is then used to guide the fluid towards the radial direction in order to reduce the long flow path through the diffuser. Four types of vane arrangements are considered: (a) 12 and 6 full length vanes, with inlet vane angles of 75° and 80°; (b) 6 short inlet vanes to give a high aspect ratio; (c) 12 and 6 short vanes located in the outer half of the vaneless diffuser passage; and (d) double-row vane rings. It is shown that short vanes deployed at the diffuser outlet not only improve the efficiency and pressure ratio but also extend the high flow operating range. Further, the introduction of short inlet vanes with an inlet angle of 80° improves the peak pressure ratio and efficiency, and extends the near surge operating range.
3
Lei, Jie, Yan Song Wang, and Hong Juan Ren. "CFD Simulation of Volute of Variable Geometry Turbocharger." Advanced Materials Research 532-533 (June 2012): 287–91. http://dx.doi.org/10.4028/www.scientific.net/amr.532-533.287.
Full textAbstract:
To study the Volute of Variable Geometry Turbocharger (VGT) flow field and the possibility of providing the basis theory for control strategy and matching with engine, in this paper, a method is presented. The 3D viscous compressible flow in the model of volute and the vanes is simulated by CFD using FVM (Finite Volume Method). And taking some VGT as an example, the simulation is carried out. The result shows that the method can display the distribution of pressure and velocity in the model clearly. The zone and the reasons resulting in loss will be found after analyzing the results, and then the turbocharger can be optimized and redesigned purposeful to reduce the losses resulted from improper figure. The distribution of pressure and velocity at open and close vanes will be found after analyzing the results, and the basis theory for VGT control strategy and matching with engine can be provided.
4
Cheng, Li, Pavlos Dimitriou, William Wang, Jun Peng, and Abdel Aitouche. "A novel fuzzy logic variable geometry turbocharger and exhaust gas recirculation control scheme for optimizing the performance and emissions of a diesel engine." International Journal of Engine Research 21, no. 8 (October 31, 2018): 1298–313. http://dx.doi.org/10.1177/1468087418809261.
Full textAbstract:
Variable geometry turbocharger and exhaust gas recirculation valves are widely installed on diesel engines to allow optimized control of intake air mass flow and exhaust gas recirculation ratio. The positions of variable geometry turbocharger vanes and exhaust gas recirculation valve are predominantly regulated by dual-loop proportional–integral–derivative controllers to achieve predefined set-points of intake air pressure and exhaust gas recirculation mass flow. The set-points are determined by extensive mapping of the intake air pressure and exhaust gas recirculation mass flow against various engine speeds and loads concerning engine performance and emissions. However, due to the inherent nonlinearities of diesel engines and the strong interferences between variable geometry turbocharger and exhaust gas recirculation, an extensive map of gains for the P, I, and D terms of the proportional–integral–derivative controllers is required to achieve desired control performance. The present simulation study proposes a novel fuzzy logic control scheme to determine appropriate positions of variable geometry turbocharger vanes and exhaust gas recirculation valve in real-time. Once determined, the actual positions of the vanes and valve are regulated by two local proportional–integral–derivative controllers. The fuzzy logic control rules are derived based on an understanding of the interactions among the variable geometry turbocharger, exhaust gas recirculation, and diesel engine. The results obtained from an experimentally validated one-dimensional transient diesel engine model showed that the proposed fuzzy logic control scheme is capable of efficiently optimizing variable geometry turbocharger and exhaust gas recirculation positions under transient engine operating conditions in real-time. Compared to the baseline proportional–integral–derivative controllers approach, both engine’s efficiency and total turbo efficiency have been improved by the proposed fuzzy logic control scheme while NOx and soot emissions have been significantly reduced by 34% and 82%, respectively.
5
Zhang, Zhongjie, Ruilin Liu, Guangmeng Zhou, Chunhao Yang, Surong Dong, Yufei Jiao, and Jiaming Ma. "Influence of varying altitudes on matching characteristics of the Twin-VGT system with a diesel engine and performance based on analysis of available exhaust energy." Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 234, no. 7 (September 18, 2019): 1972–85. http://dx.doi.org/10.1177/0954407019876220.
Full textAbstract:
A variable geometry turbocharger in series with a variable geometry turbocharger (Twin-VGT) system was designed to improve engine power at high altitudes. The influence of altitudes on the performance of the Twin-VGT system was investigated in the perspective of available exhaust energy. The interaction between exhaust flow characteristics of Twin-VGT and openings of Twin-VGT vanes was theoretically analyzed at different altitudes. Meanwhile, a model of a diesel engine matched with the Twin-VGT system was built to study the matching performance of the Twin-VGT system with engine at different altitudes. The optimal opening maps of both high-pressure and low-pressure VGT vanes at high altitudes were obtained to achieve the maximum engine power. The results showed that the optimal openings of high-pressure and low-pressure VGT vanes decreased with increase in altitudes. The operating points of the two-stage compressors located at the high efficiency region and the compressor efficiency region both exceeded 62% at different altitudes. The global expansion ratio increased with increase in altitudes and reached 4.9 at 5500 m. Compared with the VGT in series with a fixed geometry turbocharger on testing bed, exhaust energy of Twin-VGT turbines at low speeds was utilized reasonably and global pressure ratio increased by 0.69–0.94, while brake-specific fuel consumption decreased by 11.24–33.62% under low speeds above altitudes of 2500 m.
6
Kannan, Ramesh, BVSSS Prasad, and Sridhara Koppa. "Transient performance of the mixed flow and radial flow variable geometry turbines for an automotive turbocharger." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 234, no. 19 (April 15, 2020): 3762–75. http://dx.doi.org/10.1177/0954406220916493.
Full textAbstract:
In our previous paper, the steady-state test results of a mixed flow turbine with variable nozzle vanes for a turbocharger are reported. In this paper, the transient response of the same mixed flow turbine along with that of a similarly sized radial flow turbine is presented. The turbine size is suitable for handling the flow capacity of the diesel engines with swept volume up to 1.5 L. The previous experimental test set up is modified by adding a quick-release valve – actuation system before the turbine inlet to obtain a transient response. The radial and mixed flow turbines are tested for different turbine inlet pressures and for various opening positions of the nozzle vanes while matching the turbine mass flow parameters between radial and mixed flow turbines. Typically at nozzle vane openings corresponding to 50% mass flow parameter and 1.5 bar (abs) pressure at the inlet to the turbine, the transient response time for the turbine with mixed flow variable nozzle vanes configuration is about 0.770 s, as compared to 0.858 s for the turbine with radial flow variable nozzle vanes configuration.
7
Ramesh, K., BVSSS Prasad, and K. Sridhara. "A comparative study of the performance of the mixed flow and radial flow variable geometry turbines for an automotive turbocharger." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 233, no. 8 (September 10, 2018): 2696–712. http://dx.doi.org/10.1177/0954406218796043.
Full textAbstract:
A new design of a mixed flow variable geometry turbine is developed for the turbocharger used in diesel engines having the cylinder capacity from 1.0 to 1.5 L. An equivalent size radial flow variable geometry turbine is considered as the reference for the purpose of bench-marking. For both the radial and mixed flow turbines, turbocharger components are manufactured and a test rig is developed with them to carry out performance analysis. Steady-state turbine experiments are conducted with various openings of the nozzle vanes, turbine speeds, and expansion ratios. Typical performance parameters like turbine mass flow parameter, combined turbine efficiency, velocity ratio, and specific speed are compared for both mixed flow variable geometry turbine and radial flow variable geometry turbine. The typical value of combined turbine efficiency (defined as the product of isentropic efficiency and the mechanical efficiency) of the mixed flow variable geometry turbine is found to be about 25% higher than the radial flow variable geometry turbine at the same mass flow parameter of 1425 kg/s √K/bar m2 at an expansion ratio of 1.5. The velocity ratios at which the maximum combined turbine efficiency occurs are 0.78 and 0.825 for the mixed flow variable geometry turbine and radial flow variable geometry turbine, respectively. The values of turbine specific speed for the mixed flow variable geometry turbine and radial flow variable geometry turbine respectively are 0.88 and 0.73.
8
Thomas, Anand Mammen, Jensen Samuel J., Paul Pramod M., A. Ramesh, R. Murugesan, and A. Kumarasamy. "Simulation of a Diesel Engine with Variable Geometry Turbocharger and Parametric Study of Variable Vane Position on Engine Performance." Defence Science Journal 67, no. 4 (June 30, 2017): 375. http://dx.doi.org/10.14429/dsj.67.11451.
Full textAbstract:
Modelling of a turbocharger is of interest to the engine designer as the work developed by the turbine can be used to drive a compressor coupled to it. This positively influences charge air density and engine power to weight ratio. Variable geometry turbocharger (VGT) additionally has a controllable nozzle ring which is normally electro-pneumatically actuated. This additional degree of freedom offers efficient matching of the effective turbine area for a wide range of engine mass flow rates. Closing of the nozzle ring (vanes tangential to rotor) result in more turbine work and deliver higher boost pressure but it also increases the back pressure on the engine induced by reduced turbine effective area. This adversely affects the net engine torque as the pumping work required increases. Hence, the optimum vane position for a given engine operating point is to be found through simulations or experimentation. A thermodynamic simulation model of a 2.2l 4 cylinder diesel engine was developed for investigation of different control strategies. Model features map based performance prediction of the VGT. Performance of the engine was simulated for steady state operation and validated with experimentation. The results of the parametric study of VGT’s vane position on the engine performance are discussed.
9
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.
Full textAbstract:
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.
10
Hatami, M., M. C. M. Cuijpers, and M. D. Boot. "Experimental optimization of the vanes geometry for a variable geometry turbocharger (VGT) using a Design of Experiment (DoE) approach." Energy Conversion and Management 106 (December 2015): 1057–70. http://dx.doi.org/10.1016/j.enconman.2015.10.040.
Full textDissertations / Theses on the topic "Turbocharger with variable geometry vanes"
1
Vertaľ, Peter. "Provoz a údržba vozidel s přeplňovanými motory turbodmychadly." Master's thesis, Vysoké učení technické v Brně. Ústav soudního inženýrství, 2010. http://www.nusl.cz/ntk/nusl-232496.
Full textAbstract:
The goal is to measure the temperature of the turbocharger after engine shutdown.Measurements wants to show the need to keep a car engine to cool after a heavier burden on the idle speed. It would also prevent possible disruptions turbocharger. The paper also deals with the problems, construction and basic principles of operation of the turbocharger
2
Sutton, Anthony James. "Experimental evaluation of compressor variable geometry in a turbocharger compressor." Thesis, University of Bath, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.289813.
Full text
3
Žatko, Miroslav. "Optimization of the Stator Vane Aerodynamic Loading for a Turbocharger with a Variable Nozzle Turbine." Doctoral thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2015. http://www.nusl.cz/ntk/nusl-234359.
Full textAbstract:
Tato práce se zabývá problematikou aerodynamického zatížení statorových lopatek turbodmychadla s variabilní geometrií turbíny a jeho následnou optimalizací. Metody výpočtového modelování tekutin jsou aplikovány s využitím komerčního softwaru ANSYS CFX. Výpočtový model celého turbínového stupně je použit pro analýzu aerodynamického zatížení statorových lopatek v několika polohách a pro různé operační podmínky. Provedená byla detailní analýza vlivu rozložení tlaku v turbínové skříni, úhlu natočení lopatky, jakož i vlivu distančních pinů na aerodynamické zatížení. Následně bylo vyvinuto experimentální zařízení pro přímé měření aerodynamického momentu statorových lopatek s využitím testovacího zařízení s názvem Gas Stand. Toto zařízení spaluje zemní plyn a dokáže vytvořit velmi stabilní podmínky proudění při vysokých teplotách, což umožňuje vyloučit vliv pulzací plynu, vibrací motoru, jakož i vlivu řídící strategie motoru na měřenou veličinu. Výsledky experimentu jsou následně porovnány s vypočtenou hodnotou pomocí CFD modelu a je dosažená velmi dobrá shoda. Validovaný CFD model je následně zredukován s využitím podmínek cyklické symetrie na model jen jednoho segmentu statoru a rotoru. Umožňuje to výrazně zvýšit produktivitu simulací a prozkoumat několik návrhových parametrů statoru v celém rozsahu pohybu statorových lopatek. Provedená analýza citlivosti těchto parametrů položila výborný základ pro jejich následnou optimalizaci a ukázala významný potenciál několika z nich. Na základě analýzy požadavků na aerodynamické zatížení statorových lopatek byla následně vytvořena definice ideálního zatížení, která byla ustavena jako cíl pro jeho optimalizaci. Použitých bylo několik optimalizačních strategií s využitím metody analýzy působících silových vektorů a jejich výsledky byly následně zhodnoceny a porovnány z více aspektů. Výsledné optimalizované řešení bylo následně přepočteno pomocí modelu celého turbínového stupně, čímž se prokázali jeho výborné vlastnosti z hlediska aerodynamického zatížení a zvýšení účinnosti ve spodní části charakteristiky.
4
Wöhr, Michael, Elias Chebli, Markus Müller, Hans Zellbeck, Johannes Leweux, and Andreas Gorbach. "Development of a turbocharger compressor with variable geometry for heavy-duty engines." Sage, 2015. https://tud.qucosa.de/id/qucosa%3A35552.
Full textAbstract:
This article describes the first development phase of a centrifugal compressor with variable geometry which is designed to match the needs of future heavy-duty engines. Requirements of truck engines are analyzed, and their impact on the properties of the compressor map is evaluated in order to identify the most suitable kind of variable geometry. Our approach utilizes the transformation of engine data into pressure ratio and mass flow coordinates that can be displayed and interpreted using compressor maps. One-dimensional and three-dimensional computational fluid dynamics fluid flow calculations are used to identify loss mechanisms and constraints of fixed geometry compressors. Linking engine goals and aerodynamic objectives yields specific recommendations on the implementation of the variable geometry compressor.
5
Wöhr, Michael, Elias Chebli, Markus Müller, Hans Zellbeck, Johannes Leweux, and Andreas Gorbach. "Development of a turbocharger compressor with variable geometry for heavy-duty engines." Sage, 2014. https://publish.fid-move.qucosa.de/id/qucosa%3A38444.
Full textAbstract:
This article describes the first development phase of a centrifugal compressor with variable geometry which is designed to match the needs of future heavy-duty engines. Requirements of truck engines are analyzed, and their impact on the properties of the compressor map is evaluated in order to identify the most suitable kind of variable geometry. Our approach utilizes the transformation of engine data into pressure ratio and mass flow coordinates that can be displayed and interpreted using compressor maps. One-dimensional and three-dimensional computational fluid dynamics fluid flow calculations are used to identify loss mechanisms and constraints of fixed geometry compressors. Linking engine goals and aerodynamic objectives yields specific recommendations on the implementation of the variable geometry compressor.
6
Rajoo, Srithar. "Steady and pulsating performance of a variable geometry mixed flow turbocharger turbine." Thesis, Imperial College London, 2006. http://hdl.handle.net/10044/1/39159.
Full textAbstract:
Variable Geometry Turbochargers (VGT) are widely used to improve engine-turbocharger matching and currently common in diesel engines. VGT has proven to provide air boost for wide engine speed range as well as reduce turbo-lag. This thesis presents the design and experimental evaluation of a variable geometry mixed flow turbocharger turbine. The mixed flow rotor used in this study consists of 12 blades with a constant inlet blade angle of +20°, a cone angle of 50° and a tip diameter of 95.2mm. A variable geometry stator has been designed within this work, consists of 15 vanes fitted into a ring mechanism with a pivoting range between 40° and 80°. A novel nozzle vane was designed to have 40° lean stacking (from the axial direction). This geometrically achieves 3-dimensional match with the mixed flow rotor and aims to improve the turbine stage performance. A conventional straight nozzle vane was also constructed in order to have a comparative design to assess the benefits of the new lean vane. The steady flow performance results are presented for vane angle settings of 40°, 50°, 60°, 65° and 70° over a non-dimensional speed range of 0.833-1.667. The tests have been carried out with a permanent magnet eddy current dynamometer within a velocity ratio range of 0.47 to 1.09. The optimum efficiency of the variable geometry turbine was found to be approximately 5 percentage points higher than the baseline nozzleless unit. The peak efficiency of the variable geometry turbine corresponds to vane angle settings between 60° and 65°, for both the lean and straight vanes. The maximum total-to-static efficiency of the turbine with lean vanes configuration was measured to be 79.8% at a velocity ratio of 0.675. The equivalent value with straight vanes configuration is 80.4% at a velocity ratio of 0.673. The swallowing capacity of the turbine was shown to increase with the lean vanes, as much as 17% at 70° vane angle and pressure ratio of 1.7. The turbine pulsating flow performance is presented for 50% and 80% equivalent speed conditions and a pulse frequency range of 20-80 Hz, these frequencies correspond to an engine speed range of 800-3200 RPM respectively. The turbine was observed to go through a period of choking within a pulse for vane angle settings between 60°-70°. The unsteady efficiency of a nozzled turbine was found to exhibit larger deviation from the quasi-steady curve compared to a nozzlesless turbine, by as much as -19.4 percentage points. This behaviour was found to be more pronounced towards the close nozzle settings, where the blockage effect is dominant. The nozzle ring was also shown to act as a 'restrictor' which shields the turbine rotor from being completely exposed to the unsteadiness of the flow. This coupled with the phase shifting ambiguity was shown to result in the inaccuracy of the point-by-point instantaneous efficiency; where as much as 25% of a cycle exhibits instantaneous efficiency above unity. Finally the turbine was tested by adapting to the pulsating flow (20-60 Hz) by cyclic variation in the opening and closing of the nozzle vanes, called Active Control Turbocharger (A.C.T.). The nozzle vane operating schedules for each pulse period were evaluated experimentally in two general modes; natural oscillating opening/closing of the nozzle vanes due to the pulsating flow and the forced sinusoidal oscillation of the vanes to match the incoming pulsating flow. The spring stiffness was found to be a dominant factor in the effectiveness of the natural oscillation mode. In the best setting, the turbine energy extraction was shown to improve by 6.1% over a cycle for the 20 Hz flow condition. In overall it was demonstrated an optimum A.C.T. operating condition could be achieved by allowing the nozzle ring to oscillate naturally in pulsating flow, against an external spring pre-load, which eliminates the use of complex mechanism and external drive. However, the current result suggest the benefits of A.C.T. are best realised in large low speed engines.
7
Mehmood, Adeel. "Modeling, simulation and robust control of an electro-pneumatic actuator for a variable geometry turbocharger." Phd thesis, Université de Technologie de Belfort-Montbeliard, 2012. http://tel.archives-ouvertes.fr/tel-00827445.
Full textAbstract:
The choice of technology for automotive actuators is driven by the need of high power to size ratio. In general, electro-pneumatic actuators are preferred for application around the engine as they are compact, powerful and require simple controlling devices. Specially, Variable Geometry Turbochargers (VGTs) are almost always controlled with electro-pneumatic actuators. This is a challenging application because the VGT is an important part of the engine air path and the latter is responsible for intake and exhaust air quality and exhaust emissions control. With government regulations on vehicle pollutant emissions getting stringent by the year, VGT control requirements have also increased. These regulations and requirements can only be fulfilled with precise dynamic control of the VGT through its actuator. The demands on actuator control include robustness against uncertainty in operating conditions, fast and smooth positioning without vibration, limited number of measurements. Added constraints such as nonlinear dynamic behavior of the actuator, friction and varying aerodynamic forces in the VGT render classical control methods ineffective. These are the main problems that form the core of this thesis.In this work, we have addressed the above mentioned problems, using model based control complemented with robust control methods to overcome operational uncertainties and parametric variations. In the first step, a detailed physical model of an electro-pneumatic actuator has been developed; taking into account the nonlinear characteristics originating from air compressibility and friction. Means to compensate for aerodynamic force have been studied and implemented in the next step. These include model parametric adaptation and one dimensional CFD (Computational Fluid Dynamics) modeling. The complete model has been experimentally validated and a sensitivity analysis has been conducted to identify the parameters which have the greatest impact upon the actuator's behavior. The detailed simulation model has then been simplified to make it suitable for control purposes while keeping its essential behavioral characteristics (i.e. transients and dynamics). Next, robust controllers have been developed around the model for the control objective of accurate actuator positioning in presence of operational uncertainty. An important constraint in commercial actuators is that they provide output feedback only, as they are only equipped with low-cost position sensors. This hurdle has been overcome by introducing observers in the control loop, which estimate other system states from the output feedback. The estimation and control algorithms have been validated in simulation and experimentally on diesel engine test benches.
8
Gustafsson, Jonatan. "Linearization Based Model Predictive Control of a Diesel Engine with Exhaust Gas Recirculation and Variable-Geometry Turbocharger." Thesis, Linköpings universitet, Fordonssystem, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-174829.
Full textAbstract:
Engine control systems aim to ensure satisfactory output performance whilst adhering to requirements on emissions, drivability and fuel efficiency. Model predictive control (MPC) has shown promising results when applied to multivariable and nonlinear systems with operational constraints, such as diesel engines. This report studies the torque generation from a mean-value heavy duty diesel engine with exhaust gas recirculation and variable-geometry turbocharger using state feedback linearization based MPC (LMPC). This is accomplished by first introducing a fuel optimal reference generator that converts demands on torque and engine speed to references on states and control signals for the MPC controller to follow. Three different MPC controllers are considered: a single linearization point LMPC controller and two different successive LMPC (SLMPC) controllers, where the controllers are implemented using the optimization tool CasADi. The MPC controllers are evaluated with the World Harmonized Transient Cycle and the results show promising torque tracking using a SLMPC controller with linearization about reference values.
9
O'Neill, J. W. "An experimental and numerical investigation of the flow field in the turbine stator of a variable geometry turbocharger." Thesis, Queen's University Belfast, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.403436.
Full text
10
Acheson, S. K. "An experimental investigation of the flow field in the turbine stator of a variable geometry turbocharger using laser Doppler velocimetry." Thesis, Queen's University Belfast, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.403440.
Full textBook chapters on the topic "Turbocharger with variable geometry vanes"
1
Tang, H., S. Akehurst, C. J. Brace, S. Garrett, and L. Smith. "Optimisation of transient response of a gasoline engine with variable geometry turbine turbocharger." In 11th International Conference on Turbochargers and Turbocharging, 163–75. Elsevier, 2014. http://dx.doi.org/10.1533/978081000342.163.
Full text
2
Rajoo, Srithar, and Ricardo Martinez-Botas. "EXPERIMENTAL STUDY ON THE PERFORMANCE OF A VARIABLE GEOMETRY MIXED FLOW TURBINE FOR AUTOMOTIVE TURBOCHARGER." In 8th International Conference on Turbochargers and Turbocharging, 183–92. Elsevier, 2006. http://dx.doi.org/10.1016/b978-1-84569-174-5.50017-8.
Full textConference papers on the topic "Turbocharger with variable geometry vanes"
1
Rajoo, Srithar, and R. F. Martinez-Botas. "Lean and Straight Nozzle Vanes in a Variable Geometry Turbine: A Steady and Pulsating Flow Investigation." In ASME Turbo Expo 2008: Power for Land, Sea, and Air. ASMEDC, 2008. http://dx.doi.org/10.1115/gt2008-50828.
Full textAbstract:
Variable Geometry Turbines (VGT) are widely used to improve engine-turbocharger matching and currently common in diesel engines. VGT has proven to provide air boost for wide engine speed range as well as reduce turbo-lag. This paper presents the design and experimental evaluation of a variable geometry mixed flow turbocharger turbine. The tests have been carried out with a permanent magnet eddy current dynamometer within a velocity ratio range of 0.47 to 1.09. The peak efficiency of the variable geometry turbine corresponds to vane angle settings between 60° and 65°, for both the lean and straight vanes in the region of 80%. The variable geometry turbine was tested under pulsating flow with straight and lean nozzle vanes for different vane angle settings, 40Hz and 60Hz flow. In general, the range of mass flow parameter is higher in the straight nozzle vanes with an average of 66.4% and 69.7% for 40Hz and 60Hz flow respectively. The straight nozzle vanes also shows increasing pressure ratio range compared to the lean nozzle vanes, which is more apparent in the maximum pressure ratio experienced by the turbine in an unsteady cycle. In overall, the cycle averaged efficiency in the straight vane configuration is marginally higher than the lean vane. Furthermore, the difference to the equivalent quasi-steady is better in the straight vane configuration compared to the lean vane.
2
Avola, Calogero, Alberto Racca, Angelo Montanino, Carnell E. Williams, Alfonso Renella, and Michele Belluscio. "Behavior of a Variable Geometry Turbine Wheel to High Cycle Fatigue." In ASME Turbo Expo 2020: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/gt2020-14302.
Full textAbstract:
Abstract Maximization of the turbocharger efficiency is fundamental to the reduction of the internal combustion engine back-pressure. Specifically, in turbochargers with a variable geometry turbine (VGT), energy losses can be induced by the aerodynamic profile of both the nozzle vanes and the turbine blades. Although appropriate considerations on material limits and structural performance of the turbine wheel are monitored in the design and aero-mechanical optimization phases, in these stages, fatigue phenomena might be ignored. Fatigue occurrence in VGT wheels can be categorized into low and high cycle behaviors. The former would be induced by the change in turbine rotational speed in time, while the latter would be caused by the interaction between the aerodynamic excitation and blades resonating modes. In this paper, an optimized turbine stage, including unique nozzle vanes design and turbine blades profile, has been assessed for high cycle fatigue (HCF) behavior. To estimate the robustness of the turbine wheel under several powertrain operations, a procedure to evaluate HCF behavior has been developed. Specifically, the HCF procedure tries to identify the possible resonances between the turbine blades frequency of vibrations and the excitation order induced by the number of variable vanes. Moreover, the method evaluates the turbine design robustness by checking the stress levels in the component against the limits imposed by the Goodman law of the material selected for the turbine wheel. In conclusion, both the VGT design and the HCF approach are experimentally assessed.
3
Hu, Leon, Harold Sun, James Yi, Eric Curtis, and Jizhong Zhang. "Design and Analysis of a Novel Split Sliding Variable Nozzle for Turbocharger Turbine." In ASME Turbo Expo 2017: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/gt2017-64419.
Full textAbstract:
Variable geometry turbine (VGT) has been widely applied in internal combustion engines to improve the engine transient response and torque at low speed. One of the most popular variable geometry turbine is the variable nozzle turbine (VNT), in which the nozzle vanes can be rotated along the pivoting axis and thus the flow passage through the nozzle can be adjusted to match with different engine operating conditions. One disadvantage of the VNT is the turbine efficiency degradation due to the leakage flow in the nozzle endwall clearance, which is needed to allow the nozzle vanes to rotate without sticking. Especially at small nozzle open condition, there is large loading on the nozzle and high pressure gradient between the nozzle pressure and suction side. Strong leakage flow exists inside the nozzle endwall clearance from pressure side to suction side, leading to large flow loss and turbine stage efficiency degradation. In the present paper, a novel split sliding variable nozzle turbine (SSVNT) has been proposed to reduce the nozzle leakage flow and to improve turbine stage efficiency. The idea is to divide the nozzle into two parts: one part is fixed and the other part can slide along the partition surface. The mechanism of nozzle flow passage variation in SSVNT is different from that of the traditional pivoting VNT. The sliding vane and the fixed vane together form an integrated vane. The flow of the turbine is determined by the passage of the integrated vanes. When moving the sliding vane to large radius position, the nozzle flow passage opens up and the turbine has high flow capacity. When moving the sliding vane towards small radius position, the nozzle flow passage closes down and the turbine has low flow capacity. As the fixed vane doesn’t need endwall clearance, there is no leakage flow inside the fixed vane and the total leakage flow through the integrated vane can be reduced. Based on calibrated numerical modeling, the analysis results showed that there is up to 12% turbine stage efficiency improvement with the SSVNT design at small nozzle open condition while maintaining the same flow capacity and efficiency at large nozzle open condition, compared to the conventional VNT. The mechanism of efficiency improvement in the SSVNT design has also been discussed.
4
Walkingshaw, Jason, Stephen Spence, Jan Ehrhard, and David Thornhill. "An Experimental Assessment of the Effects of Stator Vane Tip Clearance Location and Back Swept Blading on an Automotive Variable Geometry Turbocharger." In ASME Turbo Expo 2012: Turbine Technical Conference and Exposition. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/gt2012-69776.
Full textAbstract:
Off-design performance is of key importance now in the design of automotive turbocharger turbines. Due to automotive drive cycles, a turbine which can extract more energy at high pressure ratios and lower rotational speeds is desirable. Typically a radial turbine provides peak efficiency at U/C values of 0.7, but at high pressure ratios and low rotational speeds the U/C value will be low and the rotor will experience high values of positive incidence at the inlet. The positive incidence causes high blade loading resulting in additional tip leakage flow in the rotor as well as flow separation on the suction surface of the blade. An experimental assessment has been performed on a scaled automotive VGS (Variable Geometry System). Three different stator vane positions have been analysed; minimum, 25% and maximum flow position. The first tests were to establish whether positioning the endwall clearance on the hub or shroud side of the stator vanes produced a different impact on turbine efficiency. Following this, a back swept rotor was tested to establish the potential gains to be achieved during off-design operation. A single passage CFD model of the test rig was developed and used to provide information on the flow features affecting performance in both the stator vanes and turbine. It was seen that off-design performance was improved by implementing clearance on the hub side of the stator vanes rather than on the shroud side. Through CFD analysis and tests it was seen that two leakage vortices form, one at the leading edge and one after the spindle of the stator vane. The vortices affect the flow angle at the inlet to the rotor, in the hub region. The flow angle is shifted to more negative values of incidence, which is beneficial at the off-design conditions but detrimental at the design point. The back swept rotor was tested with the hub side stator vane clearance configuration. The efficiency and MFR were increased at the minimum and 25% stator vane position. At the design point the efficiency and MFR were decreased. The CFD investigation showed that the incidence angle was improved at the off-design conditions, for the back swept rotor. This reduction in the positive incidence angle along with the improvement caused by the stator vane tip leakage flow, reduced flow separation on the suction surface of the rotor. At the design point both the tip leakage flow of the stator vanes and the back swept blade angle caused flow separation on the pressure surface of the rotor. This resulted in additional blockage at the throat of the rotor reducing MFR and efficiency.
5
Kannan, Ramesh, Bhamidi Prasad, and Sridhara Koppa. "Transient Response of Mixed Flow Variable Geometry Turbine for a Turbocharger." In ASME 2015 Gas Turbine India Conference. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/gtindia2015-1372.
Full textAbstract:
A specific design of mixed flow variable geometry turbine for an automotive sub 1.5 litre diesel engine turbocharger is proposed in this paper. An experimental set up is developed for measuring the steady state and transient response behaviour of the turbine at different nozzle vane opening positions. The rotor speed, pressure and temperature before and after the turbine are measured and recorded using high frequency data logging system. The steady state performance for mass flow, efficiency, velocity ratio, specific speed and the transient response behaviour of the mixed flow variable geometry turbine (MFVGT) are compared against the same parameters of a radial flow variable geometry turbine (RFVGT) of similar dimensions. Typical result indicates that the transient response of the MFVGT is faster by about 350 milliseconds than the radial at turbine inlet pressure of 0.2 bar (g).
6
Wöhr, Michael, Markus Müller, and Johannes Leweux. "Variable Geometry Compressors for Heavy Duty Truck Engine Turbochargers." In ASME Turbo Expo 2017: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/gt2017-64178.
Full textAbstract:
This paper presents the development approach, design and evaluation of three turbocharger compressors with variable geometry for heavy duty engines. The main goal is the improvement of fuel economy without sacrifices regarding any other performance criteria. In a first step, a vaned diffuser parameter study shows that efficiency improvements in the relevant operating areas are possible at the cost of reduced map width. Concluding from the results three variable geometries with varying complexity based on vaned diffusers are designed. Results from the hot gas test stand and engine test rig show that all systems are capable of increasing compressor efficiency and thus improving fuel economy in the main driving range of heavy duty engines. The most significant differences can be seen regarding the engine brake performance. Only one system meets all engine demands while improving fuel economy.
7
Heuer, Tom, Marc Gugau, Achim Klein, and Paul Anschel. "An Analytical Approach to Support High Cycle Fatigue Validation for Turbocharger Turbine Stages." In ASME Turbo Expo 2008: Power for Land, Sea, and Air. ASMEDC, 2008. http://dx.doi.org/10.1115/gt2008-50764.
Full textAbstract:
As the pursuit of improved aerodynamic performance on turbochargers continues to push the boundaries of mechanical design, the risk of high cycle fatigue (HCF) failures of turbine wheels is elevated and drives the need for improved methods of analytical predication. Turbine wheel HCF is caused by the asymmetrical aerodynamic loading associated with the application of variable geometry turbines and compromised inlet/outlet geometries that accommodate packaging turbochargers in engine compartments. Historically, the turbocharger industry has focused on blade pass as the primary cause of HCF. BorgWarner presents an analytical technique to limit the risk of HCF by calculating all critical orders that intersect blade natural frequencies and quantify the relative energy of each forced excitation frequency. The geometry of a turbine volute mainly determines the inflow angle into the turbine wheel. Thus, for the thermodynamically optimized turbine a variable inflow angle dependent on the engine operating point is desirable. The Variable Turbine Geometry (VTG) concept applies adjustable turbine inlet guide vanes to approach the ideal velocity triangle. One of the inevitable disadvantages associated with either fixed or variable turbine nozzle vanes is the generation of wakes and pressure fluctuations upstream of the turbine wheel inducer. The resulting circumferentially non-uniform flow conditions apply a transient load on the rotating turbine wheel. Due to complexity of the VTG design including non-uniformly spaced vanes and struts, the excitation sources and resulting excitation orders are not readily apparent. The analytical method described in this paper applies a transient 3D Computational Fluid Dynamics (CFD) model of the rotor-stator interaction to calculate the time-dependent pressure fluctuations experienced by the turbine wheel blade. This data is used to extract the forced excitation function at the turbine wheel. Finite Element (FE) analysis is applied to determine the mean and dynamic stress. In case of dynamic stress, system vibration modes and the influence of local harmonic excitation on blade stress amplitudes is analyzed. The fixed-speed FE results are scaled for the effect of flow and speed by use of empirical data from strain-gauge measurement. Hence, computational methods combined with experience from experimental measurements are used to determine critical rotational speeds for a given turbocharger geometry. This method allows the analyst to predict the highest energy excitation orders and reduce the risk of turbine wheel fatigue damage. Since the durability of a turbine wheel cannot yet satisfactorily be quantified by the described computational method, the analysis results are used as rotational speed input in subsequent durability tests in order to reduce the necessary amount of testing resources.
8
Gibson, Lee, Stephen Spence, Sung In Kim, Charles Stuart, Martin Schwitzke, Andre Starke, and Dietmar Filsinger. "An Investigation Into the Effect of Clearance Aspect Ratio on the Performance of a Variable Geometry Vaned Diffuser for Automotive Turbocharger Application." In ASME Turbo Expo 2020: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/gt2020-14905.
Full textAbstract:
Abstract The current state-of-the-art in radial compressor design for automotive turbocharger applications utilize impellers with a high trailing edge backsweep angle and a vaneless diffuser to provide a high boost pressure over a wide operating range. A unique feature of this type of design is that the peak efficiency island is typically located near the choke side of the compressor map. As such, the compressor efficiency is generally satisfactory when the engine is operating at high speed, such as the rated power condition. However, at low speeds the engine operating line is located close to the compressor surge line where the efficiency is generally modest. Thus, there is a need to improve the compressor efficiency at low engine speeds without compromising performance near the choke side of the map or the overall map width. Variable geometry devices have shown good potential to improve the compressor performance without a compromise in map width. In general, variability is achieved by moving walls or rotating vanes to best suit the flow conditions for a given mass flow rate. In order for this to be practically realised, a clearance or gap is required between the stationary and moving parts. This ultimately gives rise to leakage flows within the compressor stage and generally results in a lower achievable efficiency relative to the fixed geometry configuration. A study by the authors on an on/off type variable geometry vaned diffuser identified significant loss mechanisms due to the clearances required for the vanes to slide in to and out of the main flow path. Moreover, the endwall position of the clearance was found to have a marked impact on the compressor stability and peak efficiency. This paper assesses the effect of the clearance depth to width ratio (or aspect ratio) at different endwall positions with the aim of identifying an appropriate geometry and position to approach an optimised design. Steady-state Reynolds-Averaged Navier-Stokes (RANS) simulations were performed using ANSYS CFX at three operating speeds to obtain a broad sense of the effect of the clearance aspect ratio on the compressor performance. It was found that a high value of aspect ratio enabled the formation of large vortical structures in the vaned diffuser. The mixing between the core flow and the vortical structures resulted in significant losses in the vaned diffuser and affected the compressor map width differently depending on the endwall position.
9
Walkingshaw, Jason, Stephen Spence, Dietmar Filsinger, and David Thornhill. "A Numerical and Experimental Assessment of the Use of a Turbine Utilizing Splitter Blades for an Automotive Variable Geometry Turbocharger." In ASME Turbo Expo 2014: Turbine Technical Conference and Exposition. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/gt2014-26097.
Full textAbstract:
Automotive manufacturers require improved part load engine performance to further improve fuel economy. For a swing vane VGS (Variable Geometry Stator) turbine this means a more closed stator vane, to deal with the low MFRs (Mass Flow Rates), high PRs (Pressure Ratios) and low rotor rotational speeds. During these conditions the turbine is operating at low velocity ratios. As more energy is available at high pressure ratios and during lower turbocharger rotational speeds, a turbine which is efficient at these conditions is desirable. Another key aspect for automotive manufacturers is engine responsiveness. High inertia designs result in “turbo lag” which means an increased time before the target boost pressure is reached. Therefore, designs with improved performance at low velocity ratios, reduced inertia or an increased swallowing capacity are the current targets for turbocharger manufacturers. To try to meet these design targets a CFD (Computational Fluid Dynamics) study was performed on a turbine wheel using splitter blades. A number of parameters were investigated. These included splitter blade merdional length, blade number and blade angle distribution. The numerical study was performed on a scaled automotive VGS. Three different stator vane positions have been analysed. A single passage CFD model was developed and used to provide information on the flow features affecting performance in both the stator vanes and turbine. Following the CFD investigation the design with the best compromise in terms of performance, inertia and increased MFP (Mass Flow Parameter) was selected for manufacture and testing. Tests were performed on a scaled, low temperature turbine test rig. The aerodynamic flow path of the gas stand was the same as that investigated during the CFD. The test results revealed a design which had similar performance at the closed stator vane positions when compared to the baseline wheel. At the maximum MFR stator vane condition a drop of −0.6% pts in efficiency was seen. However, 5.5% increase in MFP was obtained with the additional benefit of a drop in rotor inertia of 3.7%, compared to the baseline wheel.
10
Vlaskos, Ioannis, Martin Seiler, and Joachim Schulz. "Design and Performance of the ABB TPL65 Turbocharger With Variable Turbine Geometry for Medium-Speed Diesel Engines." In ASME 2002 Internal Combustion Engine Division Fall Technical Conference. ASMEDC, 2002. http://dx.doi.org/10.1115/icef2002-524.
Full textAbstract:
This paper presents the main features of the new ABB TPL65 turbocharger with variable turbine geometry (VTG) and highlights potential improvements in engine performance and emissions as demonstrated by measurements on a medium-speed 4-stroke diesel engine at different operational points on the propeller curve and different nozzle vane positions. Calibrated engine simulation computer models have been used to compare engine behaviour, firstly with and without the VTG-turbocharger, and secondly with alternative turbocharging systems. Test results and simulations show that ABB turbochargers with VTG enable: • Fuel economy; • A strong reduction in soot emissions; • Elimination of the thermal load problem during propeller part load operation while keeping the NOx emissions within the limits defined by the IMO regulations for medium-speed diesel engines. The results of various engine computer simulations show: • Lower fuel consumption and lower engine thermal load; • Reduced derate at high ambient temperatures; • Good engine acceleration with potentially smokeless transient engine operation.