A multi-stage axial flow compressor mathematical modeling technique with application to two current turbofan compression systems

1980 ◽  
Author(s):  
C. CHAMBLEE ◽  
M. DAVIS, JR. ◽  
W. KIMZEY
Keyword(s):  
Mathematical Modeling ◽  
Axial Flow ◽  
Modeling Technique ◽  
Axial Flow Compressor ◽  
Multi Stage ◽  
Flow Compressor ◽  
Mathematical Modeling Technique

Stability of Multi-Stage Axial Flow Compressors

1964 ◽  
Vol 15 (4) ◽  
pp. 328-356 ◽  
Author(s):  
W. T. Howell
Keyword(s):  
Axial Flow ◽  
Rotational Frequency ◽  
Oscillatory Instability ◽  
Operating Point ◽  
Axial Flow Compressor ◽  
Multi Stage ◽  
Wide Range ◽  
Surge Line ◽  
Flow Compressor ◽  
The Stability

SummaryThe following theoretical investigation is concerned with the stability of the flow through a system composed of a multi-stage axial flow compressor followed by a throttle.Such an investigation was carried out by Pearson and Bowmer in 1949. In 1962 Pearson’s work on the analysis of axial flow compressor characteristics, and the accumulation of empirical data regarding factors affecting the surge line, re-awakened interest in the possibility of predicting the surge line of a multi-stage axial flow compressor-throttle system.In this paper the equations governing the stability of flow at any operating point in such a system are obtained by applying Kirchhoff’s laws to the associated electric circuit at that operating point, and the analysis is applied to a wide range of flows of the calculated characteristics of a seven-stage axial flow compressor.A study of the simplest compressor-throttle system is given, in which the equations of motion of the system are derived mechanically and electrically, and the range of validity of the equations and their stability are discussed in order to bring out the relation between the mathematics and physics of the simple system before applying these methods to multi-stage axial flow compressors.For the relatively simple electrical representation used in this paper for an axial compressor of n stages, there are shown to be 2n possible values of p, the transient rotational frequency, and these are determined over a sufficiently wide range of flows on the seven-stage compressor studied.As a result, a region of the compressor characteristic map can be marked out in which all the values of the transient rotational frequency have their real parts less than zero, corresponding to stability of operation, a region where at least one of the values of p is real and positive corresponding to non-oscillatory instability of operation, and an intermediate region where some of the values of the rotational frequency p are complex with positive real part, corresponding to oscillatory instability of operation.It is suggested that the non-oscillatory instability found here is associated with the surge and the line of inception of non-oscillatory instability with the surge line.

scholarly journals Aerodynamic Analysis and Three-Dimensional Redesign of a Multi-Stage Axial Flow Compressor

Energies ◽  
2016 ◽  
Vol 9 (4) ◽  
pp. 296 ◽  
Author(s):  
Tao Ning ◽  
Chun-Wei Gu ◽  
Wei-Dou Ni ◽  
Xiao-Tang Li ◽  
Tai-Qiu Liu
Keyword(s):  
Three Dimensional ◽  
Axial Flow ◽  
Axial Flow Compressor ◽  
Aerodynamic Analysis ◽  
Multi Stage ◽  
Flow Compressor

scholarly journals A Wide-Range Axial-Flow Compressor Stage Performance Model

1992 ◽  
Author(s):  
Gregory S. Bloch ◽  
Walter F. O’Brien
Keyword(s):  
Axial Flow ◽  
Operating Conditions ◽  
System Response ◽  
Compressor Stage ◽  
Operating Characteristics ◽  
Compression System ◽  
Axial Flow Compressor ◽  
Multi Stage ◽  
Wide Range ◽  
Flow Compressor

Dynamic compression system response is a major concern in the operability of aircraft gas turbine engines. Multi-stage compression system computer models have been developed to predict compressor response to changing operating conditions. These models require a knowledge of the wide-range, steady-state operating characteristics as inputs, which has limited their use as predicting tools. The full range of dynamic axial-flow compressor operation spans forward and reversed flow conditions. A model for predicting the wide flow range characteristics of axial-flow compressor stages was developed and applied to a 3-stage, low-speed compressor with very favorable results and to a 10-stage, high-speed compressor with mixed results. Conclusions were made regarding the inception of stall and the effects associated with operating a stage in a multistage environment. It was also concluded that there are operating points of an isolated compressor stage that are not attainable when that stage is operated in a multi-stage environment.

Large-Scale DES Analysis of Unsteady Flow Field in a Multi-Stage Axial Flow Compressor at Off-Design Condition Using K Computer

2015 ◽  
Author(s):  
Kazutoyo Yamada ◽  
Masato Furukawa ◽  
Satoshi Nakakido ◽  
Akinori Matsuoka ◽  
Kentaro Nakayama
Keyword(s):  
Boundary Condition ◽  
Unsteady Flow ◽  
Gas Turbines ◽  
Large Scale ◽  
Axial Flow ◽  
Axial Flow Compressor ◽  
Eddy Simulation ◽  
Multi Stage ◽  
Flow Phenomena ◽  
Flow Compressor

The paper presents the results of large-scale numerical simulations which were conducted for better understanding of unsteady flow phenomena in a multi-stage axial flow compressor at off-design condition. The compressor is a test rig compressor which was used for development of the industrial gas turbine, Kawasaki L30A. The compressor consists of 14 stages, the front two stages and the front half stages of which were investigated in the present study. The final goal of this study is to elucidate the flow mechanism of the rotating stall inception in the multi-stage axial compressor for actual gas turbines, and according to the test data it is considered that the 2nd stage and the 5th or 6th stage are suspected of leading to the stall. In order to capture precise flow physics in the compressor, a computational mesh for the simulation was generated to have at least several million cells per passage, which amounted to 650 million cells for the front 2-stage simulation and two billion cells for the front 7-stage simulation (about three hundred million cells for each stage). Since these were still not enough for the large-eddy simulation (LES), the detached-eddy simulation (DES) was employed, which can calculate flow fields except near-wall region by LES. The required computational resources were quite large for such simulations, so the computations were conducted on the K computer (RIKEN AICS in Japan). The simulations were well validated, showing good agreement with the measurement results obtained in the test. In the validation, the effect of the boundary condition for the casing wall was also investigated by comparing the results between the adiabatic boundary condition and the isothermal boundary condition. As for the unsteady effect, the wake/blade interaction was investigated in detail. In addition, unsteady flow phenomena in the present compressor at off-design condition were analyzed by using data mining techniques such as vortex identification and limiting streamline drawing with the LIC (line integral convolution) method. The simulation showed that they could be caused by the corner separation on the hub side.

Axial-Flow Compressor Model Based on a Cascade Stacking Technique and Neural Networks

2002 ◽  
Author(s):  
Ernesto Benini ◽  
Andrea Toffolo
Keyword(s):  
Neural Networks ◽  
Three Dimensional ◽  
Axial Flow ◽  
Design Tool ◽  
Preliminary Design ◽  
Cfd Simulations ◽  
Axial Flow Compressor ◽  
Multi Stage ◽  
Stator Vane ◽  
Flow Compressor

This paper introduces a cascade-stacking technique for the development of a gas turbine multi-stage axial-flow compressor model. A large database of stationary and rotating cascade performance is first obtained by quasi three-dimensional CFD simulations and used to train neural networks for the prediction of cascade performance under generalized conditions. Then the model directly calculates the operating point of a compressor having known geometry characteristics, including variable inlet guide/stator vane effects, as a function of mass flow rate and rotational speed. The model can also be used as a valuable preliminary design tool, obtaining geometry characteristics by imposing flow patterns.

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