CFD Simulation and testing of a Turbocharger Compressor for various Impeller Design Variables (original) (raw)
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EXPERIMENTAL ANALYSIS AND CFD SIMULATIONS OF A TURBOCHARGER COMPRESSOR
In this study, the performance of a turbocharger compressor was investigated via experimental testing and 3-D CFD simulations. The SFR1015 Turbocharger manufactured at Saffer Turbocharger in Turkey was tested experimentally under steady flow conditions. The performance map of the compressor was produced by using the test data for rotational speeds of the turbocharger between 60000 rpm and 150000 rpm. As a critical region for stable operation of the turbocharger, the surge line on the map was carefully determined. CFD simulations were carried out using Star-CCM+ software for four different operating points at the speed of 120000 rpm. The experimental analysis and CFD results under steady flow conditions show good agreement at lower flow rate with more uncertainty at higher flow speeds. Furthermore, CFD analyses showed that different geometry designs can be considered to improve the compressor performance.
Numerical analysis of a turbocharger compressor
The automotive industry is under obligation to meet regulations for emission control that has resulted in further use of turbochargers in passenger cars to enable downsizing and increase engine power density. In this study, a set of numerical simulations are conducted along two turbocharger compressor speed lines of 150,000 rpm and 80,000 rpm to analyse and validate the results against experimental data. The domain includes the full compressor stage comprising intake, impeller as a Multiple Reference Frame, diffuser and outlet. The k-omega SST turbulence model with three different mesh sizes is used to solve the compressible flow using ANSYS Fluent software. Three points on each speed-line are selected: one point each in regions close to surge and choke and a point in the stable zone of the compressor map. The simulations predict compressor performance in terms of the total-to-total pressure ratio and total-to-total efficiency. Results reveal the predicted pressure ratio error is in the range of 1-6%. At 150,000 rpm the pressure ratio is underpredicted for the point close to the surge but overpredicted for the point close to the choke. However, the pressure ratio results are within 1% difference for 80,000 rpm. In all cases, the predicted efficiency increased when a finer mesh is used. While results are close to the experimental data in both the surge and stable areas of the map, the efficiency was overpredicted up to 20% in the region close to the choke. In conclusion, the finer mesh leads to higher pressure ratio and efficiency values that overpredict the performance, especially for the point close to choke.
Design, Plant Test and CFD Calculation of a Turbocharger for a Low-Speed Engine
Applied Sciences, 2020
Various approaches and techniques are used to design centrifugal compressors. These are engineering one-dimensional and quasi-three-dimensional programs, as well as CFD Computational Fluid Dynamics (CFD) programs. The final judgment about the effectiveness of the design is given by testing the compressor or its model. A centrifugal compressor for an internal combustion engine turbocharger was designed jointly by the Research Laboratory “Gas Dynamics of Turbomachines” of Peter the Great St. Petersburg Polytechnic University (SPbPU) and RPA (Research and Production Association) “Turbotekhnika”. To check its dimensionless characteristics, the compressor was tested with two geometrically similar impellers with a diameter of 175 (TKR 175E) and 140 mm (TKR 140E). The mathematical model of the Universal Modeling Method calculates the efficiency in the design mode for all tests of both compressors with an error of 0.89%, and the efficiency for the entire characteristic with an error of 1.55...
Development of Efficient Compressors for Turbochargers
Volume 8: Microturbines, Turbochargers and Small Turbomachines; Steam Turbines, 2017
Automotive turbochargers play an important role in improving fuel economy, reducing emissions and improving drivability. Key to the improvement of the turbocharger performance is compressor efficiency. Compressors used in turbochargers are typically operated in a wide range of speed and flow. This wide operating range is a challenge to the design and improving the performance is often a fine balance between required efficiencies towards the surge, choke regions apart from having a comfortable speed margin for high altitude operations. In this study an existing compressor that best matched a 180hp commercial diesel engine application is chosen and its performance is further improved towards the lower flow region. Improvement is carried out through a set of designed experiments using a combination of Preliminary Design (PD) and Computational Fluid Dynamics (CFD) tools. Mechanical integrity of the wheel is ensured using Finite Element Analysis. A prototype is made out of the improved design and tested in an in-house gas stand. Predicted efficiency improvements are reflected in gas stand tests. Efficiency improvements in the lower flow range are observed over 7% while there is an acceptable drop (3.7%) near the peak power side. The improved compressor also shows higher part load efficiencies.
International Journal of Electrical and Electronic Engineering & Telecommunications.
Compressor's pressure ratio (PR) is the main parameter that indicates turbocharger's performance. Some tests are performed in order to measure pressure ratio and map the compressor's performance. However, limits of test setups might not be appropriate for testing all performance scenarios in different operating conditions. Additionally, prototype production costs and tests on all conditions can be very expensive and time consuming. Hence, it is more economical and appropriate to measure the performance of turbocharger compressor via numerical methods. The purpose of this paper is to create numerical models of centrifugal turbocharger compressor in different Computational Fluid Dynamics (CFD) codes and validate the models with experimental data.
Volume 1: Compressors, Fans and Pumps; Turbines; Heat Transfer; Combustion, Fuels and Emissions, 2017
Modern Internal combustion engines require high pressure ratios to perform efficiently as well as to reduce emissions. For such applications, a centrifugal compressor with high pressure ratio and broader operating range may be employed. The impeller design of such compressors plays a vital role in producing the efficient operation and hence today’s research focus rigorously over its design. The objective of the current investigation is to study the performance of centrifugal compressors based on variation in exit width, eye tip radius and shroud extension. Shroud extension have previously found to generate higher pressure rise at the same time have the least amount of losses. The pressure ratio, power and torque requirement, isentropic efficiency and thermal aspects were the main considerations for the study.
Journal of Engineering Science and Military Technologies, 2017
In this study an effort was made to develop a flow simulation modeling and performance prediction for a centrifugal compressor stage of a heavy-duty D. I. diesel engine. The model is implemented in simulation software in MATLAB language. Additionally, a contribution of this paper to demonstrate that off-design performance of a centrifugal compressor stage in a turbocharger system can be accurately simulated using commercial CFD software, with design software, FLOEFD to generate high quality meshes and model solving. The vector plots, contour plots and stream line plots are generated for better understanding of fluid flow through centrifugal compressor stage. Correlation coefficients have been introduced in the calculation program, in order to be closer to the CFD simulation results. The results obtained from mathematical computation model were validated with the CFD analysis and experimental results performed using a test bench for the variation of the performance parameters such as isentropic efficiency, power input, and total pressure ratio with mass flow rate, the results are also presented in graphical form. The results reveal that reasonable agreement between mathematical models, the numerical results obtained from the CFD simulations and the real measurements; the maximum difference never exceeds 5%. The results indicate that the developed mathematical computation model can yield better predictions of performance for a centrifugal compressor stage in a turbocharger system.
International Journal of Performability Engineering, 2018
Turbocharger is used to increase the efficiency of an engine. In the turbocharger, a centrifugal compressor is used. Centrifugal compressor failure has been a main issue in recent years. The failure of the centrifugal compressor is because of surge and stall. Surge occurs because pressure at the receiver is greater than the pressure at the compressor. So, gas flow will reverse and surge occurs. This work-study is based on reducing surge and stall. We can prevent the tendency of surge and stall by changing the factors affecting the change in pressure. We can change the pressure by changing the density of gas, number of impellers, impeller diameter, inlet and volute geometry and flow regulation. Hence, in this paper, we perform the CFD analysis of the centrifugal compressor by changing the geometry.
Optimization of the inlet air line of an automotive turbocharger
International Journal of Engine Research, 2013
This paper presents different aspects of air inlet behaviour near the inducer of a radial compressor and shows how the geometry can contribute to its stability and performance. Unfortunately, the space reserved for installation of an automotive turbocharger in a vehicle is constantly being reduced, so it is necessary to study the effects that elbows and abrupt changes in flow directions originate on the compressor performance. The work presented in this paper studies the effect that different 90°elbows have on the compressor with respect to its ideal, straight, no-elbow configuration, in order to obtain the best possible elbow configuration.
Numerical simulation of air flow through turbocharger compressors with dual volute design
2009
In this paper, turbocharger centrifugal compressors with dual volute design were investigated by using Computational Fluid Dynamics (CFD) method. The numerical simulation focused on the air flow from compressor impeller inlet to volute exit, and the overall performance level and range are predicted. The numerical investigation revealed that the dual volute design could separate the compressor into two operating regions: ''high efficiency" and ''low efficiency" regions with different air flow characteristics, and treating these two regions separately with dual diffuser design showed extended stable operating range and improved efficiency by comparing with conventional single volute design. The ''dual sequential volute" concept also showed the potential to further extend the stable operating range by closing one of the volutes at low air flow rates. Furthermore, by comparing with other alternate designs such as variable diffuser vanes and variable inlet guide vanes, the operation of the dual sequential volute also features relatively simple control and calibration.