scholarly journals Low-inertia centrifugal compressor wheels: Aerodynamic and mechanical design

2017 ◽  
Vol 9 (2) ◽  
pp. 168781401769069 ◽  
Author(s):  
Tore Fischer ◽  
Joerg R Seume
Keyword(s):  
Fuel Cell ◽  
Numerical Model ◽  
Centrifugal Compressor ◽  
Gasoline Engine ◽  
State Of The Art ◽  
Mechanical Design ◽  
Operating Stability ◽  
Compressor Impeller ◽  
Performance Results ◽  
Stage Efficiency

A new centrifugal compressor impeller design approach is presented, focusing on electrically driven compressors for gasoline engine and fuel cell applications. The performance and mechanical integrity are evaluated based on numerical simulations. Additionally, the numerical model is applied to several variations of the diffuser and volute geometries, in order to evaluate stage characteristics for diffuser area ratios of 110% and 150%, volute area ratios from 60% to 90%, and diffuser pinch ratios from 60% to 80%. The preliminary performance results show the capability to achieve a flow range comparable to a larger state-of-the-art impeller, with minor penalties regarding stage efficiency and near surge operating stability.

On the Influence of a Hubside Exducer Cavity and Bleed Air in a Close-Coupled Centrifugal Compressor Stage

2017 ◽  
Vol 139 (7) ◽  
Author(s):  
Peter Kaluza ◽  
Christian Landgraf ◽  
Philipp Schwarz ◽  
Peter Jeschke ◽  
Caitlin Smythe
Keyword(s):  
Centrifugal Compressor ◽  
Pressure Field ◽  
State Of The Art ◽  
Test Rig ◽  
Cfd Simulations ◽  
Trailing Edge ◽  
Loss Mechanism ◽  
Aero Engine ◽  
Computational Fluid Dynamics Cfd ◽  
Stage Efficiency

In aero-engine applications, centrifugal compressors are often close-coupled with their respective diffusers to increase efficiency at the expense of a reduced operating range. The aim of this paper is to show that state-of-the art steady-state computational fluid dynamics (CFD) simulations can model a hubside cavity between an impeller and a close-coupled diffuser and to enhance the understanding of how the cavity affects performance. The investigated cavity is located at the impeller trailing edge, and bleed air is extracted through it. Due to geometrical limitations, the mixing plane is located in the cavity region. Therefore, the previous analyses used only a cut (“simple”) model of the cavity. With the new, “full” cavity model, the region inside the cavity right after the impeller trailing edge is not neglected anymore. The numerical setup is validated using the experimental data gathered on a state-of-the art centrifugal compressor test-rig. For the total pressure field in front of the diffuser throat, a clear improvement is achieved. The results presented reveal a drop in stage efficiency by 0.5%-points caused by a new loss mechanism at the impeller trailing edge. On the hubside, the fundamentally different interaction of the cavity with the coreflow increases the losses in the downstream components resulting in the mentioned stage efficiency drop. Finally, varying bleed air extraction is investigated with both cavity models. Only the full cavity (FC) model captures the changes measured in the experiment.

Improved Performance Model of Turbocharger Centrifugal Compressor

2008 ◽  
Author(s):  
Mingyang Yang ◽  
Xinqian Zheng ◽  
Yangjun Zhang ◽  
Zhigang Li
Keyword(s):  
Prediction Model ◽  
Centrifugal Compressor ◽  
Performance Prediction ◽  
Gasoline Engine ◽  
Performance Model ◽  
New Model ◽  
Compressor Impeller ◽  
Accurate Performance ◽  
Improved Performance

This paper improves the conventional performance prediction model by correlating recirculation loss at the outlet of compressor impeller with its rotational speeds. The validation is carried out on a gasoline engine turbocharger compressor. The result shows that accuracy of the new model is greatly improved over the whole operating speeds, which brings possibility to the high accurate performance prediction in off design condition and a powerful tool for the matching between turbocharger and engine.

The Development of Centrifugal Compressor Impeller

2008 ◽  
Author(s):  
C. Xu ◽  
R. S. Amano
Keyword(s):  
Centrifugal Compressor ◽  
State Of The Art ◽  
Pressure Ratio ◽  
Structure Design ◽  
Centrifugal Compressors ◽  
Rotating Speed ◽  
Operating Range ◽  
High Pressure Ratio ◽  
Current State ◽  
Compressor Impeller

Impeller is one of the key components of industrial centrifugal compressors and turbochargers. Aerodynamic and structure designs of the impeller are critical to the success of the whole compressor stages. The requirements for efficiency and operating range of industrial centrifugal compressors and turbochargers have been increased dramatically compared with the situation in the past. The efficiency of newly developed low-pressure ratio centrifugal compressor has reached the possible level of the machine. However, the efficiency level of intermediate and high-pressure ratio machine still have gap between the current state-of-the-art and possible level. The challenge for centrifugal compressor design is to keep the efficiency level at state-of-the-art and increase the compressor operating range. Increase of the compressor operating range without sacrificing compressor peak efficiency is difficult to achieve. The product globalization requires one product design, which can be used in all locations. In some counties, due to the technology differences, electricity frequencies variations could be 10%. Turbocharger compressors work at different rotational speeds for majority of the time. The compressor impeller rotating speeds change in certain range. The impeller rotating speed variation makes the impeller structure design more challenging. In this study, a full-3D impeller was designed to optimize impeller aerodynamic performance and structure characteristics.

Centrifugal compressor design

1998 ◽  
Vol 213 (2) ◽  
pp. 139-155 ◽  
Author(s):  
P. M. Came ◽  
C. J. Robinson
Keyword(s):  
Centrifugal Compressor ◽  
State Of The Art ◽  
Mechanical Design ◽  
Preliminary Design ◽  
Aerodynamic Design ◽  
Design Procedures ◽  
Wide Range ◽  
Compressor Design ◽  
Computational Fluid Dynamics Cfd ◽  
Physical Phenomena

Centrifugal compressors are used in a wide range of applications in which performance and mechanical integrity are invariably among the paramount design objectives. There is therefore continuing interest in the development of a sound understanding of the relevant physical phenomena and in the systematic application of the knowledge base that is the forerunner of the established design procedures. The paper reviews centrifugal compressor design methods that are commonly used in industry and reviews the underlying engineering science supporting the design practices. The design process, starting with the preliminary design and its reliance on empirical rules through to state-of-the-art aerodynamic design using computational fluid dynamics (CFD), is presented. The essentials of impeller mechanical design are also included in the paper.

On the Influence of a Hubside Exducer Cavity and Bleed Air in a Close-Coupled Centrifugal Compressor Stage

2016 ◽  
Author(s):  
Peter Kaluza ◽  
Christian Landgraf ◽  
Philipp Schwarz ◽  
Peter Jeschke ◽  
Caitlin Smythe
Keyword(s):  
Centrifugal Compressor ◽  
Pressure Field ◽  
State Of The Art ◽  
Cavity Model ◽  
Test Rig ◽  
Cfd Simulations ◽  
Trailing Edge ◽  
Loss Mechanism ◽  
Aero Engine ◽  
Stage Efficiency

In aero-engine applications, centrifugal compressors are often close-coupled with their respective diffusers to increase efficiency at the expense of a reduced operating range. The aim of this paper is to show that state-of-the art steady state CFD simulations can model a hubside cavity between an impeller and a close-coupled diffuser and to enhance the understanding of how the cavity affects performance. The investigated cavity is located at the impeller trailing edge and bleed air is extracted through it. Due to geometrical limitations the mixing plane is located in the cavity region. Therefore, previous analyses used only a cut (“simple”) model of the cavity. With the new, “full” cavity model, the region inside the cavity right after the impeller trailing edge is not neglected anymore. The numerical setup is validated using experimental data gathered on a state-of-the art centrifugal compressor test-rig. For the total pressure field in front of the diffuser throat a clear improvement is achieved. The results presented reveal a drop in stage efficiency by 0.5%-points caused by a new loss mechanism at the impeller trailing edge. On the hubside, the fundamentally different interaction of the cavity with the coreflow increases the losses in the downstream components resulting in the mentioned stage efficiency drop. Finally, varying bleed air extraction is investigated with both cavity models. Only the full cavity model captures the changes measured in the experiment.

Sensitivity analysis and optimization of a CO2 centrifugal compressor impeller with a vaneless diffuser

2021 ◽  
Author(s):  
Leandro Oliveira Salviano ◽  
Elóy Esteves Gasparin ◽  
Vitor Cesar N. Mattos ◽  
Bruno Barbizan ◽  
Fábio Saltara ◽  
...  
Keyword(s):  
Sensitivity Analysis ◽  
Centrifugal Compressor ◽  
Vaneless Diffuser ◽  
Compressor Impeller

scholarly journals Structural Response of a Single-Stage Centrifugal Compressor to Fluid-Induced Excitations at Low-Flow Operating Condition: Experimental and Numerical Study

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4292
Author(s):  
Kirill Kabalyk ◽  
Andrzej Jaeschke ◽  
Grzegorz Liśkiewicz ◽  
Michał Kulak ◽  
Tomasz Szydłowski ◽  
...  
Keyword(s):  
Centrifugal Compressor ◽  
Numerical Study ◽  
Structural Response ◽  
Flow Coefficient ◽  
Low Flow ◽  
Dynamic Strain ◽  
Duct Acoustics ◽  
Numerical Noise ◽  
Partial Load ◽  
Compressor Impeller

The article describes an assessment of possible changes in constant fatigue life of a medium flow-coefficient centrifugal compressor impeller subject to operation at close-to-surge point. Some aspects of duct acoustics are additionally analyzed. The experimental measurements at partial load are presented and are primarily used for validation of unidirectionally coupled fluid-structural numerical model. The model is based on unsteady finite-volume fluid-flow simulations and on finite-element transient structural analysis. The validation is followed by the model implementation to replicate the industry-scale loads with reasonably higher rotational speed and suction pressure. The approach demonstrates satisfactory accuracy in prediction of stage performance and unsteady flow field in vaneless diffuser. The latter is deduced from signal analysis relying on continuous wavelet transformations. On the other hand, it is found that the aerodynamic incidence losses at close-to-surge point are underpredicted. The structural simulation generates considerable amounts of numerical noise, which has to be separated prior to evaluation of fluid-induced dynamic strain. The main source of disturbance is defined as a stationary region of static pressure drop caused by flow contraction at volute tongue and leading to first engine-order excitation in rotating frame of reference. Eventually, it is concluded that the amplitude of excitation is too low to lead to any additional fatigue.

scholarly journals Genetic Algorithm Optimization of the Volute Shape of a Centrifugal Compressor

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Martin Heinrich ◽  
Rüdiger Schwarze
Keyword(s):  
Numerical Model ◽  
Centrifugal Compressor ◽  
Total Pressure ◽  
Pressure Ratio ◽  
Pressure Rise ◽  
Maximum Efficiency ◽  
Algorithm Optimization ◽  
Cross Sectional ◽  
Design Variables ◽  
Design Speed

A numerical model for the genetic optimization of the volute of a centrifugal compressor for light commercial vehicles is presented. The volute cross-sectional shape is represented by cubic B-splines and its control points are used as design variables. The goal of the global optimization is to maximize the average compressor isentropic efficiency and total pressure ratio at design speed and four operating points. The numerical model consists of a density-based solver in combination with the SSTk-ωturbulence model with rotation/curvature correction and the multiple reference frame approach. The initial validation shows a good agreement between the numerical model and test bench measurements. As a result of the optimization, the average total pressure rise and efficiency are increased by over1.0%compared to the initial designs of the optimization, while the maximum efficiency rise is nearly 2.5% atm˙corr=0.19 kg/s.

Parametric Sensitivity Tests — European PEM Fuel Cell Stack Test Procedures

2014 ◽  
Author(s):  
Samuel Simon Araya ◽  
Søren Juhl Andreasen ◽  
Søren Knudsen Kær
Keyword(s):  
Fuel Cell ◽  
Low Temperature ◽  
Pem Fuel Cell ◽  
Test Procedures ◽  
Fuel Cell Stack ◽  
Parametric Sensitivity ◽  
Benchmark Tests ◽  
Sensitivity Tests ◽  
Performance Results ◽  
Fuel Cell Operation

As fuel cells are increasingly commercialized for various applications, harmonized and industry-relevant test procedures are necessary to benchmark tests and to ensure comparability of stack performance results from different parties. This paper reports the results of parametric sensitivity tests performed based on test procedures proposed by a European project, Stack-Test. The sensitivity of a Nafion-based low temperature PEMFC stack’s performance to parametric changes was the main objective of the tests. Four crucial parameters for fuel cell operation were chosen; relative humidity, temperature, pressure, and stoichiometry at varying current density. Furthermore, procedures for polarization curve recording were also tested both in ascending and descending current directions.

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