scholarly journals Searching for the Most Suitable Loss Model Set for Subsonic Centrifugal Compressors Using an Improved Method for Off-Design Performance Prediction

Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8545
Author(s):  
Patrik Kovář ◽  
Adam Tater ◽  
Pavel Mačák ◽  
Tomáš Vampola
Keyword(s):  
Experimental Data ◽  
Performance Prediction ◽  
Prediction Algorithm ◽  
Centrifugal Compressors ◽  
Loss Model ◽  
Design Performance ◽  
Model Sets ◽  
Design Behaviour ◽  
Model Set ◽  
Physical Phenomena

This work investigates loss model sets based on empirical loss correlations for subsonic centrifugal compressors. These loss models in combination with off-design performance prediction algorithms make up an essential tool in predicting off-design behaviour of turbomachines. This is important since turbomachines rarely work under design conditions. This study employs an off-design performance prediction algorithm based on an iterative process from Galvas. Modelling of ten different loss mechanisms and physical phenomena is involved in this approach and is thoroughly described in this work. Geometries of two subsonic compressors were reconstructed and used in the evaluation of individual loss correlations in order to obtain a suitable loss model. Results of these variations are compared to experimental data. In addition, 4608 loss model sets were created by taking all possible combinations of individual loss estimations from which three promising candidates were selected for further investigation. Finally, off-design performance of both centrifugal compressors was computed. These results were compared to experimental data and to other loss model sets from literature. The newly composed loss model set No. 2137 approximates experimental data over a 21.2% better in relative error than the recent Zhang set and nearly a 36.7% better than the outdated Oh’s set. Therefore, set No. 2137 may contribute to higher precision of centrifugal turbomachines’ off-design predictions in the upcoming research.

Investigation of Off-Design Performance of Vaned Diffusers in Centrifugal Compressors: Part I — A Channel-Wedge Diffuser

2002 ◽  
Author(s):  
JongSik Oh
Keyword(s):  
Experimental Data ◽  
Centrifugal Compressor ◽  
Performance Prediction ◽  
Limited Range ◽  
Design Parameters ◽  
Centrifugal Compressors ◽  
Design Point ◽  
Numerical Investigations ◽  
Design Performance

Experimental and numerical investigations of the off-design performance of a simple channel-wedge diffuser in a small centrifugal compressor are presented. Surge and choke conditions as well as design point are considered using somewhat limited range of experimental data and also supplementary 3D CFD results. Some critical meanline design parameters’ behavior is investigated numerically, to render the basis for improved modelings in the meanline performance prediction.

scholarly journals Modeling and Efficiency Prediction of Aeroengine Centrifugal Pump Integrated Loss Model Based on One-Dimensional Flow

2018 ◽  
Vol 36 (5) ◽  
pp. 807-815
Author(s):  
Jiangfeng Fu ◽  
Huacong Li ◽  
Ding Fan ◽  
Wenbo Shen ◽  
Xianwei Liu
Keyword(s):  
Experimental Data ◽  
Centrifugal Pump ◽  
Relative Error ◽  
Performance Prediction ◽  
Design Parameters ◽  
Hydraulic Loss ◽  
Pump Efficiency ◽  
Centrifugal Pumps ◽  
Loss Model ◽  
Cfd Method

This paper was presented a method of integrated loss model by considering all kinds of loss type in centrifugal pumps. The geometric structure and loss mechanism of the flow parts in the centrifugal pump were analyzed, such as suction chamber, impeller, vaneless diffuser chamber, volute type water collecting chamber and outlet diffusion section. The hydraulic loss model, volume loss model, friction loss and mechanical loss model of centrifugal pump were established respectively by combining the flow theory. Finally, an integrated loss model of centrifugal pump was constructed, which can establish the relationship between the 12 main design parameters and pump efficiency of the centrifugal pump. Then the performance prediction of an aeroengine fuel centrifugal pump was carried out based on the loss model, and the loss model predictions were compared with the experimental data and CFD simulation performance prediction data. Simulation results show that:The efficiency predicted value relative error of centrifugal pump is less than 2.8% between the loss model and the experimental data. The computational efficiency of CFD is less than 4.4% compared with the experimental data in the design condition. The relative error is about 1.6% between the CFD method and the loss model which shows that the loss model predicts efficiency accuracy is better than the CFD method. It shows that this method can be used to predict the efficiency performance of centrifugal pump under design process.

Mean Streamline Aerodynamic Performance Analysis of Centrifugal Compressors

1995 ◽  
Vol 117 (3) ◽  
pp. 360-366 ◽  
Author(s):  
R. H. Aungier
Keyword(s):  
Experimental Data ◽  
Performance Analysis ◽  
Centrifugal Compressor ◽  
Performance Prediction ◽  
Validation Studies ◽  
Prediction Models ◽  
Aerodynamic Performance ◽  
Performance Data ◽  
Centrifugal Compressors ◽  
Test Uncertainty

Aerodynamic Performance prediction models for centrifugal compressor impellers are presented. In combination with similar procedures for stationary components, previously published in the open literature, a comprehensive mean streamline performance analysis for centrifugal compressor stages is provided. The accuracy and versatility of the overall analysis is demonstrated for several centrifugal compressor stages of various types, including comparison with intrastage component performance data. Detailed validation of the analysis against experimental data has been accomplished for over a hundred stages, including stage flow coefficients from 0.009 to 0.15 and pressure ratios up to about 3.5. Its application to turbocharger stages includes pressure ratios up to 4.2, but with test uncertainty much greater than for the data used in the detailed validation studies.

An Evaluation of Vaneless Diffuser Modelling Methods as a Means of Improving the Off-Design Performance Prediction of Centrifugal Compressors

2015 ◽  
Author(s):  
Charles Stuart ◽  
Stephen Spence ◽  
Dietmar Filsinger ◽  
Andre Starke ◽  
Sung In Kim ◽  
...  
Keyword(s):  
Test Data ◽  
Performance Prediction ◽  
Standard Test ◽  
Flow Coefficient ◽  
Inlet Section ◽  
Vaneless Diffuser ◽  
Centrifugal Compressors ◽  
Cfd Simulations ◽  
Local Flow ◽  
Design Performance

An evaluation of existing 1-D vaneless diffuser design tools in the context of improving the off-design performance prediction of automotive turbocharger centrifugal compressors is described. A combination of extensive gas stand test data and single passage CFD simulations have been employed in order to permit evaluation of the different methods, allowing conclusions about the relative benefits and deficiencies of each of the different approaches to be determined. The vaneless diffuser itself has been isolated from the incumbent limitations in the accuracy of 1-D impeller modelling tools through development of a method to fully specify impeller exit conditions (in terms of mean quantities) using only standard test stand data with additional interstage static pressure measurements at the entrance to the diffuser. This method allowed a direct comparison between the test data and 1-D methods through sharing common inputs, thus achieving the aim of diffuser isolation. Crucial to the accuracy of determining the performance of each of the vaneless diffuser configurations was the ability to quantify the presence and extent of the spanwise aerodynamic blockage present at the diffuser inlet section. A method to evaluate this critical parameter using CFD data is described herein, along with a correlation for blockage related to a new diffuser inlet flow parameter ⚡, equal to the quotient of the local flow coefficient and impeller tip speed Mach number. The resulting correlation permitted the variation of blockage with operating condition to be captured.

scholarly journals Design of a structure model set for inorganic compounds based on ping-pong balls linked with snap buttons

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Ryo Horikoshi ◽  
Hiroyuki Higashino ◽  
Yoji Kobayashi ◽  
Hiroshi Kageyama
Keyword(s):  
High School Students ◽  
Coordination Compounds ◽  
Periodic Structures ◽  
Inorganic Compounds ◽  
Structure Model ◽  
School Students ◽  
Model Sets ◽  
Ping Pong ◽  
Hands On ◽  
Model Set

Abstract Structure model sets for inorganic compounds are generally expensive; their distribution to all students in a class is therefore usually impractical. We have therefore developed a structure model set to illustrate inorganic compounds. The set is constructed with inexpensive materials: ping-pong balls, and snap buttons. The structure model set can be used to illustrate isomerism in coordination compounds and periodic structures of ceramic perovskites. A hands-on activity using the structure model set was developed for high school students and was well-received by them. Despite the concepts being slightly advanced for them, the students’ retention of the knowledge gained through the activity was tested a week after they completed the activity and was found to be relatively high, demonstrating the usefulness of the activity based on the structure model set.

Performance prediction of transonic axial multistage compressor based on one-dimensional meanline method

2021 ◽  
pp. 095765092199881
Author(s):  
Yingying Zhang ◽  
Shijie Zhang
Keyword(s):  
Experimental Data ◽  
Mass Flow ◽  
Flow Separation ◽  
Performance Prediction ◽  
Factor Model ◽  
Separation Method ◽  
Prediction Program ◽  
Blockage Factor ◽  
Reliability And Robustness ◽  
Work Done

This study proposes a 1D meanline program for the modeling of modern transonic axial multistage compressors. In this method, an improved blockage factor model is proposed. Work-done factor that varies with the compressor performance conditions is added in this program, and at the same time a notional blockage factor is kept. The coefficient of deviation angle model is tuned according to experimental data. In addition, two surge methods that originated from different sources are chosen to add in and compare with the new method called mass flow separation method. The salient issues presented here deal first with the construction of the compressor program. Three well-documented National Aerodynamics and Space Administration (NASA) axial transonic compressors are calculated, and the speedlines and aerodynamic parameters are compared with the experimental data to verify the reliability and robustness of the proposed method. Results show that consistent agreement can be obtained with such a performance prediction program. It was also apparent that the two common methods of surge prediction, which rely upon either stage or overall characteristic gradients, gave less agreement than the method called mass flow separation method.

Loss Generation in Transonic Turbine Blading

2017 ◽  
Author(s):  
Penghao Duan ◽  
Choon S. Tan ◽  
Andrew Scribner ◽  
Anthony Malandra
Keyword(s):  
Experimental Data ◽  
Boundary Layer ◽  
Mach Number ◽  
High Speed ◽  
Turbine Blades ◽  
Surface Boundary ◽  
Loss Model ◽  
Exit Mach Number ◽  
Loss Characteristic ◽  
Shock Loss

The measured loss characteristic in a high-speed cascade tunnel of two turbine blades of different designs showed distinctly different trend with exit Mach number ranging from 0.8 to 1.4. Assessments using steady RANS computation of the flow in the two turbine blades, complemented with control volume analyses and loss modelling, elucidate why the measured loss characteristic looks the way it is. The loss model categorizes the total loss in terms of boundary layer loss, trailing edge loss and shock loss; it yields results in good agreement with the experimental data as well as steady RANS computed results. Thus RANS is an adequate tool for determining the loss variations with exit isentropic Mach number and the loss model serves as an effective tool to interpret both the computational and experimental data. The measured loss plateau in Blade 1 for exit Mach number of 1 to 1.4 is due to a balance between a decrease of blade surface boundary layer loss and an increase in the attendant shock loss with Mach number; this plateau is absent in Blade 2 due to a greater rate in shock loss increase than the corresponding decrease in boundary layer loss. For exit Mach number from 0.85 to 1, the higher loss associated with shock system in Blade 1 is due to the larger divergent angle downstream of the throat than that in Blade 2. However when exit Mach number is between 1.00 and 1.30, Blade 2 has higher shock loss. For exit Mach number above around 1.4, the shock loss for the two blades is similar as the flow downstream of the throat is completely supersonic. In the transonic to supersonic flow regime, the turbine design can be tailored to yield a shock pattern the loss of which can be mitigated in near equal amount of that from the boundary layer with increasing exit Mach number, hence yielding a loss plateau in transonic-supersonic regime.

Design and Optimization of Multi-Stage Centrifugal Compressors With Uncertainty Quantification of Off Design Performance

2017 ◽  
Author(s):  
A. Romei ◽  
R. Maffulli ◽  
C. Garcia Sanchez ◽  
S. Lavagnoli
Keyword(s):  
Uncertainty Quantification ◽  
Oil And Gas ◽  
Low Cost ◽  
Design Procedure ◽  
Design Tool ◽  
Test Case ◽  
Centrifugal Compressors ◽  
Design Performance ◽  
Leading Role ◽  
Multi Stage

The use of multi-stage centrifugal compressors carries out a leading role in oil and gas process applications. Green operation and market competitiveness require the use of low-cost reliable compression units with high efficiencies and wide operating range. A methodology is presented for the design optimization of multi-stage centrifugal compressors with prediction of the compressor map and estimation of the uncertainty limits. A one-dimensional (1D) design tool has been developed that automatically generates a multi-stage radial compressor satisfying the target machine requirements based on a few input parameters. The compressor performance map is then assessed using the method proposed by Casey-Robinson [1], and the approach developed by Al-Busaidi-Pilidis [2]. The off-design performance method relies on empirical correlations calibrated on the performance maps of many single-stage centrifugal compressors. An uncertainty quantification study on the predicted performance maps was conducted using Monte Carlo method (MCM) and generalized Polynomial Chaos Expansion (gPCE). Finally, the design procedure has been coupled to an in-house optimizer based on evolutionary algorithms. The complete design procedure has been applied to a multi-stage industrial compressor test case. A multi-objective optimization of a multi-stage industrial compressor has been performed targeting maximum compressor efficiency and flow range. The results of the optimization show the existence of optimum compressor architectures and how the Pareto fronts evolve depending on the number of stages and shafts.

scholarly journals OECD-NEA Expert Group on Multi-Physics Experimental Data, Benchmarks and Validation

2018 ◽  
Author(s):  
Timothy Valentine ◽  
Kostadin Ivanov ◽  
Maria Avramova ◽  
Alessandro Petruzzi ◽  
Jean-Pascal Hudelot ◽  
...  
Keyword(s):  
Experimental Data ◽  
Nuclear Energy ◽  
Great Promise ◽  
Expert Group ◽  
Energy Agency ◽  
Validation Data ◽  
Task Forces ◽  
Spatial Domains ◽  
Physics Modeling ◽  
Physical Phenomena

High-fidelity, multi-physics modeling and simulation (M&S) tools are being developed and utilized for a variety of applications in nuclear science and technology and show great promise in their abilities to reproduce observed phenomena for many applications. Even with the increasing fidelity and sophistication of coupled multi-physics M&S tools, the underpinning models and data still need to be validated against experiments that may require a more complex array of validation data because of the great breadth of the time, energy and spatial domains of the physical phenomena that are being simulated. The expert group on Multi-Physics Experimental Data, Benchmarks and Validation (MPEBV) of the Nuclear Energy Agency (NEA) of the Organization for Economic Cooperation and Development (OECD) was formed to address the challenges with the validation of such tools. The work of the MPEBV expert group is shared among three task forces to fulfill its mandate and specific exercises are being developed to demonstrate validation principles for common industrial challenges. This paper describes the overall mission of the group, the specific objectives of the task forces, the linkages among the task forces, and the development of a validation exercise that focuses on a specific reactor challenge problem.

Sign in / Sign up

Export Citation Format

Share Document