Performance Prediction of Twin-Entry Turbocharger Turbines

2002 ◽  
Author(s):  
Shahram Ghasemi ◽  
Ebrahim Shirani ◽  
Ali Hajilouy-Benisi
Keyword(s):  
Performance Prediction ◽  
Flow Direction ◽  
Prediction Method ◽  
One Dimensional ◽  
Plane Normal ◽  
Partial Admission ◽  
Single Entry ◽  
Radial Velocity Profile ◽  
Inlet Conditions ◽  
The One

In this paper, the performance of the twin-entry radial flow turbine under steady state and partial admission conditions is modeled. The method, which is developed here, is based on one-dimensional performance prediction. In one-dimensional modeling, the flow properties are assumed constant on a plane normal to the flow direction. This assumption is in contrast with the flow at the rotor entry of a twin-entry turbine under partial admission condition. In this study the one-dimensional performance prediction method for single-entry turbine is modified to analyze the twin-entry turbine. In particular, the loss coefficients due to friction, clearance and blade loading, which are already developed for single-entry turbines, are modified. Also additional losses in the rotor are considered because of twin-entry rotor inlet conditions and the rotor-mixing losses. Indeed in a single-entry turbine with symmetric volute the flow tends to move toward the shroud. A correlation for the radial velocity profile at the rotor entry for this case is obtained and is considered to be optimum. Then the rotor mixing loss is estimated. Finally a model based on the above mentioned matters is developed. The results obtained from the model are compared with experimental results and good agreements are obtained. In this paper, special behaviors of the flow in the twin-entry turbine are also investigated and some physical interpretations are presented.

Performance Evaluation of a Regenerative Blower for Hydrogen Recirculation Application in Fuel Cell Vehicles

2006 ◽  
Author(s):  
Young-Hoon Kim ◽  
Shin-Hyoung Kang
Keyword(s):  
Fuel Cell ◽  
Performance Prediction ◽  
Three Dimensional ◽  
Prediction Method ◽  
Theoretical Models ◽  
Hydrogen Gas ◽  
Fuel Cell Vehicles ◽  
One Dimensional ◽  
Loss Models ◽  
The One

Regenerative blowers are used for hydrogen gas recirculation application in fuel cell vehicles. In this paper we discuss the performance of theoretical models that describe the complex three dimensional flows in regenerative blowers. A one-dimensional performance prediction code is developed based on theoretical models and loss models. Numerical calculation is also performed using a commercial CFD code to analyze the three dimensional flows in a regenerative blower. The results of numerical analysis are used to evaluate the performance of the designed blower and improve the accuracy of performance prediction by correcting the loss models. The results of performance predictions are compared with measured data of a prototype regenerative blower to validate the one-dimensional performance prediction method.

Improving a one-dimensional centrifugal compressor performance prediction method

2005 ◽  
Vol 219 (8) ◽  
pp. 653-659 ◽  
Author(s):  
E Swain
Keyword(s):  
Centrifugal Compressor ◽  
Performance Prediction ◽  
Fluid Dynamic ◽  
Three Dimensional ◽  
Axial Compressor ◽  
Prediction Method ◽  
Compressor Cascade ◽  
One Dimensional ◽  
Compressor Performance ◽  
Cfd Analyses

A one-dimensional centrifugal compressor performance prediction technique that has been available for some time is updated as a result of extracting the component performance from three-dimensional computational fluid dynamic (CFD) analyses. Confidence in the CFD results is provided by comparison of overall performance for one of the compressor examples. The extracted impeller characteristic is compared with the original impeller loss model, and this indicated that some improvement was desirable. The position of least impeller loss was determined using a traditional axial compressor cascade method, and suitable algebraic expressions were derived to match the CFD data. The merit of the approach lies with the relative ease that CFD component performance currently can be achieved and adjusting one-dimensional methods to agree with the CFD-derived models.

The one-Dimensional Unsteady Flow Prediction Method for Pressure Waves in High-Speed Subway and its Applications

2011 ◽  
Vol 94-96 ◽  
pp. 1967-1970
Author(s):  
Chao Hui Zhou ◽  
Yuan Gui Mei
Keyword(s):  
Unsteady Flow ◽  
High Speed ◽  
Prediction Method ◽  
Pressure Waves ◽  
Subway Tunnel ◽  
One Dimensional ◽  
Flow Prediction ◽  
Cross Section Area ◽  
Section Area ◽  
The One

With the speed-up of subway, the discomfort problem of passengers caused by pressure waves becomes more and more serious. The prediction method of the pressure waves based on the one-dimensional unsteady compressible non-homentropic flow model and the method of characteristics is introduced, and the program is developed which can be used to calculate the pressure waves not only produced by single train passing through subway tunnel with airshafts, but also produced when the train starts or stops. On this base, the influence of the train speed and the cross-section area of airshafts to the comfort of passengers in the subway is researched. All these work provides the foundation for the development of the one-dimensional unsteady flow prediction method for pressure waves produced by the train passing through subway tunnel.

Prediction of the steady and non-steady flow performance of a highly loaded mixed flow turbine

1998 ◽  
Vol 212 (3) ◽  
pp. 173-184 ◽  
Author(s):  
M Abidat ◽  
M Hachemi ◽  
M K Hamidou ◽  
N C Baines
Keyword(s):  
Steady State ◽  
Performance Prediction ◽  
Internal Combustion Engines ◽  
Prediction Method ◽  
Combustion Engines ◽  
Steady State Flow ◽  
Mixed Flow ◽  
One Dimensional ◽  
Flow Equations ◽  
State Flow

This paper describes a method for predicting the performance under both turbine inlet steady state and non-steady state flow conditions of a mixed flow turbine used for turbocharged internal combustion engines. The mixed flow turbine steady state performances computed with the steady state performance prediction method are in good agreement with the experimental results obtained in the Imperial College turbocompressor cold air test rig. The unsteady state performance is computed using a one-dimensional model based on the solution of the unsteady one-dimensional flow equations. These equations are solved in the volute by a finite difference method using a four-step explicit Runge—Kutta scheme. The instantaneous volute exit condition is provided by the steady state rotor performance prediction model with the assumption of a quasi-steady state flow in the rotor. The computed instantaneous performances are in reasonable agreement with published experimental data for the same mixed flow turbine. The unsteady flow model is also used to study the effects of the frequency and the amplitude of the pulse on the performances of the mixed flow turbine.

Experimental and Theoretical Investigation of Twin-Entry Radial Inflow Gas Turbine With Unsymmetrical Volute Under Full and Partial Admission Conditions

2007 ◽  
Author(s):  
Habib Aghaali ◽  
Ali Hajilouy-Benisi
Keyword(s):  
Experimental Investigation ◽  
Steady State ◽  
Gas Turbine ◽  
Performance Prediction ◽  
Test Facility ◽  
Maximum Efficiency ◽  
Special Test ◽  
One Dimensional ◽  
Wide Range ◽  
Partial Admission

In this paper the performance characteristics of turbocharger twin-entry radial inflow gas turbine with unsymmetrical volute and rotor tip diameter of 73.6 mm in steady state and under full and partial admission conditions are investigated. The employed method is based on one dimensional performance prediction which is developed for partial admission conditions. Furthermore this method is developed for unsymmetrical volute of the turbine considering flow specifications. Experimental investigation of the research carried out on special test facility under full and partial admission conditions for a wide range of speed. The comparison of experimental and modeling results shows good agreements. Interestingly, the turbine maximum efficiency occurs when the shroud side inlet mass flow is higher than that of hub side.

Aerodynamic Performance Prediction of Transonic Axial Multistage Compressors Based on One-Dimensional Meanline Method

2020 ◽  
Author(s):  
Yingying Zhang ◽  
Shijie Zhang ◽  
Yunhan Xiao
Keyword(s):  
Performance Prediction ◽  
Pressure Rise ◽  
Direct Calculation ◽  
One Dimensional ◽  
Axial Compressors ◽  
Surge Margin ◽  
Multistage Compressors ◽  
Aerodynamic Parameters ◽  
And Performance ◽  
The One

Abstract The one-dimensional meanline method is of great importance for the design and performance prediction of multistage axial compressors. The models adopted in it, such as incidence, deviation and loss, considering real-fluid effects, determine whether the compressors’ operating behavior can be simulated accurately or not. This paper describes an improved meanline stage-stacking approach for the modelling of modern transonic axial multistage compressors. The improvement embodied in this study is mainly focused on deviation and surge margin prediction, which is the result of a combination of the previous models and models’ correction. One of the coefficients in the deviation angle model is corrected. A new surge model, different from the well-known maximum static pressure rise method of Koch and Smith, is introduced into this program and its advantage lies in higher accuracy and direct calculation instead of proposing a judgment criterion. Three well-documented NASA axial transonic compressors are calculated by this meanline method, and the speedlines and aerodynamic parameters are compared with the experimental data to verify the method presented in this paper. A discussion of the result then follows.

ACOUSTIC ATTENUATION CHARACTERISTICS OF STRAIGHT-THROUGH PERFORATED TUBE SILENCERS AND RESONATORS

2008 ◽  
Vol 16 (03) ◽  
pp. 361-379 ◽  
Author(s):  
Z. L. JI
Keyword(s):  
Performance Prediction ◽  
Transmission Loss ◽  
Three Dimensional ◽  
Geometrical Parameters ◽  
Mean Flow ◽  
Acoustic Attenuation ◽  
One Dimensional ◽  
The One ◽  
Attenuation Characteristics ◽  
Perforated Tube

The one-dimensional analytical solutions are derived and three-dimensional substructure boundary element approaches are developed to predict and analyze the acoustic attenuation characteristics of straight-through perforated tube silencers and folded resonators without mean flow, as well as to examine the effect of nonplanar waves in the silencers and resonators on the acoustic attenuation performance. Comparisons of transmission loss predictions with the experimental results for prototype straight-through perforated tube silencers demonstrated that the three-dimensional approach is needed for accurate acoustic attenuation performance prediction at higher frequencies, while the simple one-dimensional theory is sufficient at lower frequencies. The BEM is then used to investigate the effects of geometrical parameters on the acoustic attenuation characteristics of straight-through perforated tube silencers and folded resonators in detail.

A Study on Flow in Duct Constructed of Nonwoven Fabric

2003 ◽  
Author(s):  
Masahiko Sakamoto ◽  
Toshiyuki Sawabe ◽  
Kiichiro Izumi
Keyword(s):  
Pipe Flow ◽  
Flow Direction ◽  
Flow Characteristics ◽  
Nonwoven Fabric ◽  
Circular Pipe ◽  
Small Range ◽  
Air Filter ◽  
One Dimensional ◽  
Circular Pipe Flow ◽  
The One

The purpose of this paper is to investigate both the flow characteristics in the sock type of the air filter constructed of nonwoven fabric and the effect on drag reduction in a circular pipe flow by means of the wall coated with nonwoven fabric. The nonwoven fabric used in these experiments is an electret one made of polypropylene, and the fiber distribution is a random laying. The fiber is about 4 μ m in diameter and 0.6 mm in thickness of web. The nonwoven fabric without adhesion of dust was used in these experiments. The pressure distribution along the flow direction was measured for various parameters such as Reynolds number, shape of the air filter, and type of nonwoven fabric. The value of the permeability for the present nonwoven fabric is on the order of 10−11(m2) within the limits of this experiment. The pressure in the sock type of the air filter increases with increasing Re. The experimental results can be explained by Darcy’s law as d/L is larger than 0.1. In the small range of Re the calculated values obtained by the one-dimensional flow model qualitatively agree with those obtained by this experiment. It was proven that the wall coated with the nonwoven fabric is effective to reduce the drag in the circular pipe flow.

The Formation of a Shock Wave in a Blade Passage of a Partial Admission Turbine

1968 ◽  
Vol 90 (4) ◽  
pp. 555-562 ◽  
Author(s):  
W. A. Woods ◽  
F. Kuo-Hua Chu ◽  
R. W. Mann
Keyword(s):  
Shock Wave ◽  
Supersonic Nozzle ◽  
Theoretical Work ◽  
Dimensional Theory ◽  
Impulse Turbine ◽  
Blade Passage ◽  
One Dimensional ◽  
Partial Admission ◽  
The One ◽  
Hydraulic Analogy

The problem of unsteady flow in the blade passage of a partial admission impulse turbine with supersonic nozzle flow is introduced. Previous work carried out at M.I.T. revealed the presence of a shock wave at the entrance to the blade passages and this report sets out to predict the formation of such a shock wave using a one-dimensional theory. The one-dimensional theory is discussed in some detail and a novel method for dealing with the inflow boundary conditions is developed. Details of a characteristic calculation are given, and this is matched with a shock wave analysis to predict the formation of the shock wave. The implications of the theoretical work are discussed and experimental results obtained from a hydraulic analogy are presented which confirm the analysis.

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