The numerical study of the performance characteristics of a radial turbine with varying inlet blade angle

2011 ◽  
pp. 169-181
Author(s):  
Liam Barr ◽  
Stephen W. T. Spence ◽  
Tony McNally
Keyword(s):  
Numerical Study ◽  
Performance Characteristics ◽  
Blade Angle ◽  
Radial Turbine

Improved Performance of a Radial Turbine Through the Implementation of Back Swept Blading

2008 ◽  
Author(s):  
Liam Barr ◽  
Stephen W. T. Spence ◽  
Paul Eynon
Keyword(s):  
Numerical Study ◽  
Numerical Models ◽  
Internal Flow ◽  
Turbine Rotor ◽  
Point Of View ◽  
Blade Angle ◽  
Element Analysis ◽  
Numerical Predictions ◽  
Radial Turbine ◽  
Optimum Velocity

This report details the numerical investigation of the performance characteristics and internal flow fields of an 86 mm radial turbine for a turbocharger application. A new blade was subsequently designed for the 86 mm rotor which departed from the conventional radial inlet blade angle to incorporate a 25° inlet blade angle. A comparative analysis between the two geometries is presented. Results show that the 25° back swept blade offers significant increases in efficiency while operating at lower than optimum velocity ratios (U/C). This enhanced efficiency at off-design conditions would significantly improve turbocharger performance where the turbine typically experiences lower than optimum velocity ratios while accelerating during engine transients. A commercial CFD code was used to construct single passage steady state numerical models. The numerical predictions show off-design performance gains of 2% can be achieved, while maintaining design point efficiency. Primary and secondary flow patterns are examined at various planes within the turbine blade passage and reasons for the increase in performance are discussed. A finite element analysis has been conducted to assess the stress implications of introducing a non-radial angle at turbine rotor inlet. A modal analysis was also carried out in order to identify the natural frequencies of the turbine geometry, thus calculating the critical speeds corresponding to the induction of the excitational frequencies from the stator vanes. Although the new blade design has resulted in stress increases in some regions, the numerical study has shown that it is feasible from both an aerodynamic and structural point of view to increase the performance characteristic of a radial turbine through the implementation of back swept blading.

Interactional Effects of Inlet Guide Vane and Blade Angle on Hydraulic Performance Characteristics of a Submersible Axial-Flow Pump

2018 ◽  
Author(s):  
Youn-Sung Kim ◽  
Hyeon-Seok Shim ◽  
Kwang-Yong Kim
Keyword(s):  
Stokes Equations ◽  
Guide Vane ◽  
Incidence Angle ◽  
Axial Flow ◽  
Performance Characteristics ◽  
Inlet Guide Vane ◽  
Computational Domain ◽  
Blade Angle ◽  
Axial Flow Pump ◽  
Flow Pump

This study aims to evaluate effects of blade pitch and inlet guide vane (IGV) angle on the performance characteristics of a submersible axial-flow pump. According to the results of the previous study, the efficiency at the design and over-load conditions were significantly affected by the angle of IGV due to change in the incidence angle. To investigate the interactional effects of IGV and blade angle are analyzed using three-dimensional Reynolds-averaged Navier-Stokes equations with shear stress transport turbulence model. The hexahedral grids are used in the computational domain and a grid-dependency test is performed to obtain an optimal number of the grids. In this study, combinations of three different blade angles and two different IGV angles are tested. Adjusting angle of IGV increases the total pressure of the pump with a blade pitch increase, which can increase the efficiency of the pump in operating range.

Performance Characteristics of Two- and Three-Dimensional Impellers in Centrifugal Compressors

1988 ◽  
Vol 110 (1) ◽  
pp. 110-114 ◽  
Author(s):  
H. Harada
Keyword(s):  
Centrifugal Compressor ◽  
Closed Loop ◽  
Three Dimensional ◽  
Test Stand ◽  
Performance Characteristics ◽  
Working Fluid ◽  
Angle Distribution ◽  
Blade Angle ◽  
Operating Range ◽  
Overall Performance

The overall performance of two- and three-dimensional impellers of a centrifugal compressor were tested and compared. A closed-loop test stand with Freon gas as the working fluid was employed for the experiments. The inlet and outlet velocity distributions of all impellers were measured using three-hole cobra probes. As a result, it has been revealed that three-dimensional impeller in terms of efficiency, head coefficient, and operating range. Further, it has also been clarified that the impeller slip factor is affected by blade angle distribution.

On the Implication of Porosity Configuration on Lithium-Ion Cell Performance: A Numerical Study

2020 ◽  
Vol 18 (1) ◽  
Author(s):  
Brajesh Kumar Kanchan ◽  
Pitambar R. Randive ◽  
Sukumar Pati
Keyword(s):  
Specific Energy ◽  
Salt Concentration ◽  
Power Dissipation ◽  
Numerical Study ◽  
Lithium Concentration ◽  
Negative Electrode ◽  
Lithium Ion ◽  
Performance Characteristics ◽  
Cell Performance ◽  
Lithium Ion Cell

Abstract The present study numerically investigates the implication of different porosity configurations, viz., uniform, algebraic, trigonometric, logarithmic, and stepwise constant porosities at the negative electrode on performance characteristics of Lithium-ion cell. We assess the merit of nonuniform porosity over uniform one in terms of cell performance characteristics, viz., specific energy, capacity, electrolyte salt concentration, local volumetric current density, power dissipation density, and solid lithium concentration. Our results reveal that specific energy and capacity are found to be maximum when the porosity increases logarithmically in the direction from the negative electrode–current collector to negative electrode–separator interface. Also, it is found that the variation of power dissipation density and electrolyte salt concentration characteristics are dictated by the interplay of the porosity and the length of the negative electrode. Furthermore, the effect of charging rates (quick charge, fast charge, and ultrafast charge) on cell performance is carried out. It is seen that the increment in C-rates strongly influences the cell performance. It is found that the average capacity increases by 44% at the higher C-rate, i.e., 5C when the porosity increases logarithmically. On the contrary, sinusoidal variation in porosity yields in the worst cell performance. The findings of the present study bear utility toward designing an efficient battery system that can operate for a higher number of cycles with minimal power dissipation density and can fit into the ultrafast charging technique.

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