Performance Evaluation of a Turbocharger Compressor by Varying the Exit Width, Eye Tip Radius and Extending the Shroud to Study Their Impact Using Computational Modelling (original) (raw)
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THERMODYNAMIC DESIGN OF CENTRIFUGAL COMPRESSOR FOR TURBOCHARGER
The purpose of a turbocharger is to increase the power output of an engine by supplying compressed air to the engine intake manifold so that fuel can be burnt efficiently. In this work, thermodynamic design of a high pressure ratio centrifugal compressor, for 75 kW class engines, was carried out. A pressure ratio of 2.8 was considered with a compressor rotational speed of 60,000 RPM. The compressor was designed for vane less diffuser. The impeller designs were obtained using circular method, with six divisions. The CAD models were built using CATIA. The geometry was then tested using Computational Fluid Dynamics (CFD) simulations to verify the thermodynamic based design.
Numerical Flow Analysis of a Centrifugal Compressor with Ported and without Ported Shroud
SAE Technical Paper Series, 2014
Turbochargers are commonly used in automotive engines to increase the internal combustion engine performance during off design operation conditions. When used, a most wide operation range for the turbocharger is desired, which is limited on the compressor side by the choke condition and the surge phenomenon. The ported shroud technology is used to extend the operable working range of the compressor, which permits flow disturbances that block the blade passage to escape and stream back through the shroud cavity to the compressor inlet. The impact of this technology on a speed-line at near optimal operation condition and near surge operation condition is investigated. A numerical study investigating the flow-field in a centrifugal compressor of an automotive turbocharger has been performed using Large Eddy Simulation. The wheel rotation is handled by the numerically expensive sliding mesh technique. In this analysis, the full compressor geometry (360 deg) is considered. Numerical solutions with and without ported shroud for a near optimal operation condition and near-surge operation condition. The flow-field of the different cases is analyzed to elucidate the functionality of the ported shroud. In agreement with previous observations, it was found that the ported shroud reduces the flow disturbances in the blade passage for all operating conditions. However, the compressor efficiency for the off-design operation condition was found to be higher without the ported shroud, supporting the findings reported recently by an experimental investigation. The computational results are validated with experimental measurements in terms of the performance parameters and available Particle Image Velocimetry data.
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...
Effect of impeller geometry on performance characteristics of centrifugal compressor
2019
Centrifugal Compressors play an essential role in oil, gas and petrochemical industries. Their extensive usage is due to their smooth operation and high reliability compared to other other compressor types. One of the main characteristics of these turbomachines is their performance curve, which is an important criterion for selecting the appropriate compressor for a desired working condition. In the presented article, the effect of impeller’s geometry on performance curve and other compressors characteristics is numerically investigated. The 3D CFD code is used to achieve the performance curves that are dedicated to each geometrical configuration. The results indicate that some of the selected geometrical parameters have a significant effect on performance curve margins. Increasing the shroud angle moves the surge point to the higher flow coefficients, while the pressure ratio remains constant and increasing the blade’s trailing edge angle, leads to increase in pressure ratio.
CFD Simulation and testing of a Turbocharger Compressor for various Impeller Design Variables
2019
To meet the future engine emission legislations and efficiently use the fuel, automotive industries are downsizing the engine and depending on the turbocharger to deliver the high power when necessary. However, the design of a turbocharger compressor is very complex due to the transient nature and the high flow velocity and compressibility of the airflow. Modelling the airflow in the compressor requires high computation resources which could be challenging especially, when examining operating conditions that are close to surge and choke limits [1,2]. Different level of CFD complexity can be used depending on the level of details needed and objective of the study [3]. To ensure the assumptions made is not affecting the results, experimental testing using either in-house or commercial test facilities are commonly employed [2]. Various design parameters can affect the compressor performance and its range of operations [4,5]. Among these variables the inlet vane angle which can be varied to achieve high performance at various rotational speeds [6,7]. In this work, 3-D CFD model has been developed to simulate the airflow under steady operating conditions. The model utilizes RANS together with k- turbulence model to evaluate the compressor performance at various impeller rotational speed 60,000 to 140,000 rpm and inlet mass flow rates. Experimental test rig using continuous steady flow has been employed to validate the CFD model and reasonable agreement has been achieved. The effect of three design parameters (impeller leading-edge angle, impeller trailing-edge angle, splitter blade length) are examined and the effect of their deviation from its optimum value on the performance of the turbocharger compressor in terms of pressure boost, efficiency and range of the turbocharger are evaluated.
Energies, 2019
The performance of an automotive turbocharger centrifugal compressor has been studied by developing a comprehensive one-dimensional (1D) code as verified through experimental results and a three-dimensional (3D) model. For 1D analysis, the fluid stream in compressor is modeled using governing gas dynamics equations and the loss mechanisms have been investigated and added to the numerical model. The objective is to develop and offer a 1D model, which considers all loss mechanisms, slip, blockage and also predicts the surge margin and choke conditions. The model captures all features from inlet duct through to volute discharge. Performance characteristics are obtained using preliminary geometry and the blade characteristics. A 3D numerical model was also created and a viscous solver used for investigating the compressor characteristics. The numerical model results show good agreement with experimental data through compressor pressure ratio and efficiency. The effect of the main compre...
유체기계 연구개발 발표회 논문집, 2015
The prediction and design of the aerodynamic performance of a compressor are crucial requirements to properly evaluate the aerodynamic performance and characteristics during preliminary design of a centrifugal compressor because it is not clear to figure out the internal flow property of a compressor including complicated three dimensional turbulent flow. In this study the industrial centrifugal compressor was calculated for variations of mass flow and blade Mach number with 2 cases of different number of diffuser vanes. One of the major cause of the impeller loss is the pressure drop when the operating mass flow rate closes to choking flow coefficient. Momentum transfer and loss characteristics of the impeller are important to understand impeller characteristics. The method was suggested to estimate the impeller performance characteristics.
Parametric Study on Impeller Exit Blade Width Variation on Centrifugal Compressor Performance
2017
The work addresses an imperious issue of enhancing centrifugal flow compressor performance by modifying the impeller blade design. Recent advancements have reported in enhancement of centrifugal compressor performance by the impeller with extended shroud by 10%. Present work extends to explore the significance geometric and design parametric variation of varying exit blade width and its implications on the compressor performance. Numerical simulations were carried out for the selected cases of extended shroud by 10% along with the width at exit blade width increased by 5% and 10%. The numerical predictions were validated with the compressor theory and matched reasonably well. Results indicates higher static pressure rise with reduced losses and increased efficiency with exit blade width variation. The stagnation pressure distribution increases at exit of diffuser due to rotating vaneless diffuser. The presence of rotating vaneless diffuser yields smooth entry flow profiles, thereby ...
A Review on Centrifugal Compressor Design Methods
The use of turbochargers has increased in response to strengthened automotive exhaust emission and fuel consumption regulations for global environmental protection. Most centrifugal compressors are required to operate over a broad range of flow rates and to provide a high pressure ratio with high efficiency. The internal flow of a centrifugal compressor is very problematic with 3-dimensional and unsteady flow phenomena, and the analysis of flow phenomena and expansion of the operational range are difficult problems. Review is done for gathering the efficient method for designing and analyzing the centrifugal compressor. In order to meet these demands the application of variable geometry techniques is often considered and applied.