scholarly journals Aerodynamic Modeling of Multistage Compressor Flowfields: Part 2 — Modeling Deterministic Stresses

1997 ◽  
Author(s):  
Edward J. Hall
Keyword(s):  
Test Data ◽  
Axial Flow ◽  
Time Dependent ◽  
State University ◽  
Turbine Engine ◽  
Prediction Scheme ◽  
Proposed Model ◽  
Multistage Compressors ◽  
Multistage Compressor ◽  
Flow Compressor

The primary purpose of this study was to investigate improved numerical techniques for predicting flows through multistage compressors. The vehicle chosen for this study was the Pennsylvania State University Research Compressor (PSRC). The PSRC facility consists of a 3-1/2 stage axial flow compressor which shares design features which are consistent with embedded stages of modern gas turbine engine axial flow compressors. In Part 2 of this two part paper, time-dependent predictions of rotor/stator/rotor aerodynamic interactions were employed to quantify the levels and distribution of deterministic stresses resulting from the average-passage flowfield description. Details of the spanwise and blade-to-blade distributions of the velocity correlations are examined and compared with results based on physical deterministic flow structures such as blade wakes and clearance flows. The predicted “apparent” wake profile decay resulting from the interaction of the wake through a downstream blade row is presented and compared with test data. This “apparent” wake profile decay is employed to define a simplified model for deterministic stress correlations in a steady state flowfield prediction scheme which retains the “mixing plane” methodology. Calculations based on this proposed model are described and predicted results are compared with both time-dependent predictions and test data. The resulting prediction strategy is both computational efficient and contains sufficient physical realism to permit its use in design studies.

Aerodynamic modelling of multistage compressor flow fields Part 2: Modelling deterministic stresses

1998 ◽  
Vol 212 (2) ◽  
pp. 91-107 ◽  
Author(s):  
E J Hall
Keyword(s):  
Flow Field ◽  
Test Data ◽  
Axial Flow ◽  
Time Dependent ◽  
Computationally Efficient ◽  
Turbine Engine ◽  
Prediction Scheme ◽  
Multistage Compressors ◽  
Aerodynamic Modelling ◽  
Flow Compressor

The primary purpose of this study was to investigate improved numerical techniques for predicting flows through multistage compressors. The vehicle chosen for this study was the Pennsylvania State University Research Compressor (PSRC). The PSRC facility consists of a 3 1/2-stage axial flow compressor which shares design features which are consistent with embedded stages of modern gas turbine engine axial flow compressors. In Part 2 of this two-part paper, time-dependent predictions of rotor- stator-rotor aerodynamic interactions are employed to quantify the levels and distribution of deterministic stresses resulting from the average-passage flow field description. Details of the spanwise and blade-to- blade distributions of the velocity correlations are examined and compared with results based on physical deterministic flow structures such as blade wakes and clearance flows. The predicted ‘apparent’ wake profile decay resulting from the interaction of the wake through a downstream blade row is presented and compared with test data. This ‘apparent’ wake profile decay is employed to define a simplified model for deterministic stress correlations in a steady state flow field prediction scheme which retains the ‘mixing- plane’ methodology. Calculations based on this proposed model are described and predicted results are compared with both time-dependent predictions and test data. The resulting prediction strategy is computationally efficient and also contains sufficient physical realism to permit its use in design studies.

scholarly journals Aerodynamic Modeling of Multistage Compressor Flowfields: Part 1 — Analysis of Rotor/Stator/Rotor Aerodynamic Interaction

1997 ◽  
Author(s):  
Edward J. Hall
Keyword(s):  
Flow Analysis ◽  
Axial Flow ◽  
Sensitivity Study ◽  
Time Dependent ◽  
State University ◽  
Turbine Engine ◽  
Mesh Density ◽  
Multistage Compressors ◽  
Dependent Flow ◽  
Flow Compressor

The primary purpose of this study was to investigate improved numerical techniques for predicting flows through multistage compressors. The vehicle chosen for this study was the Pennsylvania State University Research Compressor (PSRC). The PSRC facility consists of a 3-1/2 stage axial flow compressor which shares design features which are consistent with embedded stages of modern gas turbine engine axial flow compressors. In Part 1 of this two part paper, several Computational Fluid Dynamics (CFD) techniques were applied to predict both steady and unsteady flows through the PSRC facility. Inter-blade row coupling via a circumferentially-averaged mixing plane approach was employed for steady flow analysis. A mesh density sensitivity study was performed to define the minimum mesh requirements necessary to achieve reasonable agreement with the experimental data. Time dependent flow predictions were performed using a time dependent interblade row coupling technique. These calculations evaluated the aerodynamic interactions occurring between the second rotor, second stator, and third rotor for the PSRC rig.

Aerodynamic modelling of multistage compressor flow fields Part 1: Analysis of rotor-stator-rotor aerodynamic interaction

1998 ◽  
Vol 212 (2) ◽  
pp. 77-89 ◽  
Author(s):  
E J Hall
Keyword(s):  
Flow Analysis ◽  
Axial Flow ◽  
Sensitivity Study ◽  
Time Dependent ◽  
Turbine Engine ◽  
Mesh Density ◽  
Multistage Compressors ◽  
Dependent Flow ◽  
Aerodynamic Modelling ◽  
Flow Compressor

The primary purpose of this study was to investigate improved numerical techniques for predicting flows through multistage compressors. The vehicle chosen for this study was the Pennsylvania State University Research Compressor (PSRC). The PSRC facility consists of a 3 1/2-stage axial flow compressor which shares design features which are consistent with embedded stages of modern gas turbine engine axial flow compressors. In Part 1 of this two-part paper, several computational fluid dynamics techniques were applied to predict both steady and unsteady flows through the PSRC facility. Interblade row coupling via a circumferentially averaged mixing-plane approach was employed for steady flow analysis. A mesh density sensitivity study was performed to define the minimum mesh requirements necessary to achieve reasonable agreement with the experimental data. Time-dependent flow predictions were performed using a time-dependent interblade row coupling technique. These calculations evaluated the aerodynamic interactions occurring between rotor 2, stator 2 and rotor 3 for the PSRC rig.

Effect of Tip Clearance on the Prediction of Nonsynchronous Vibrations in Axial Compressors

2012 ◽  
Vol 135 (1) ◽  
Author(s):  
Martin Drolet ◽  
Huu Duc Vo ◽  
Njuki W. Mureithi
Keyword(s):  
Operating Temperature ◽  
Axial Flow ◽  
Tip Clearance ◽  
Turbine Engine ◽  
Tip Clearance Flow ◽  
Background Theory ◽  
Proposed Model ◽  
Clearance Flow ◽  
Flow Compressor ◽  
Nonsynchronous Vibrations

This work investigates the effect of tip clearance size and operating temperature on the predictions of the critical rotor speed at which nonsynchronous vibrations (NSV) can be encountered in a turbine engine axial flow compressor. It has been proposed that the tangential tip clearance flow, observed at high blade loading near stall, can act as an impinging resonant jet on the upcoming blades and could be the underlying physics behind NSV. A model, in the form of an equation to predict the critical blade tip speed at which NSV can occur, was proposed based on the Jet-Core Feedback Theory and was experimentally verified by Thomassin et al. (2008, “Experimental Demonstration to the Tip Clearance Flow Resonance Behind Compressor NSV,” Proceedings of GT2008: ASME Turbo Expo Power for Land, Sea and Air, Berlin, Germany, Jun. 9–13, Paper No. GT2008-50303). In the equation, a factor k that was called the “tip instability convection coefficient” was measured experimentally and found to be influenced by the tip clearance size and operating temperature. This factor has a significant impact on the accuracy of the NSV predictions obtained using the proposed model. This paper propose a numerical experiment to determine the effect of tip clearance size and temperature on k, in order to improve the critical NSV tip speed predictions using the proposed model. A review of the NSV model is presented along with the relevant background theory on the subject. Two different blade geometries are simulated to provide a generic approach to the study. The leakage flow velocity is calculated to estimate k and a correlation is proposed to model the behavior of the k parameter as a function of the tip clearance size. The latter was found to significantly improve the critical NSV speed predictions. The effect of operating temperature on k is also discussed. Finally, the variation of k with the aerodynamic loading is assessed and compared with available data in the literature to strengthen the generic nature of the results.

Effect of Tip Clearance on the Prediction of Non-Synchronous Vibrations in Axial Compressors

2011 ◽  
Author(s):  
Martin Drolet ◽  
Huu Duc Vo ◽  
Njuki W. Mureithi
Keyword(s):  
Operating Temperature ◽  
Axial Flow ◽  
Tip Clearance ◽  
Turbine Engine ◽  
Tip Clearance Flow ◽  
Axial Compressors ◽  
Background Theory ◽  
Proposed Model ◽  
Clearance Flow ◽  
Flow Compressor

This work investigates the effect of tip clearance size and operating temperature on the predictions of the critical rotor speed at which Non-Synchronous Vibrations (NSV) can be encountered in a turbine engine axial flow compressor. It has been proposed that the tangential tip clearance flow, observed at high blade loading near stall, can act as an impinging resonant jet on the upcoming blades and could be the underlying physics behind NSV. A model, in the form of an equation to predict the critical blade tip speed at which NSV can occur, was proposed based on the Jet-Core Feedback Theory and was experimentally verified by Thomassin et al. [8]. In the equation, a factor k that was called the “tip instability convection coefficient” was measured experimentally and found to be influenced by the tip clearance size and operating temperature. This factor has a significant impact on the accuracy of the NSV predictions obtained using the proposed model. This paper propose a numerical experiment to determine the effect of tip clearance size and temperature on k, in order to improve the critical NSV tip speed predictions using the proposed model. A review of the NSV model is presented along with the relevant background theory on the subject. Two different blade geometries are simulated to provide a generic approach to the study. The leakage flow velocity is calculated to estimate k and a correlation is proposed to model the behavior of the k parameter as a function of the tip clearance size. The latter was found to significantly improve the critical NSV speed predictions. The effect of operating temperature on k is also discussed. Finally, the variation of k with the aerodynamic loading is assessed and compared with available data in the literature to strengthen the generic nature of the results.

Design and Development of a 12:1 Pressure Ratio Compressor for the Ruston 6-MW Gas Turbine

1982 ◽  
Author(s):  
F. Carchedi ◽  
G. R. Wood
Keyword(s):  
Gas Turbine ◽  
Test Data ◽  
Pressure Ratio ◽  
Axial Flow ◽  
Aerodynamic Design ◽  
Design And Development ◽  
Surge Line ◽  
Flow Compressor ◽  
Industrial Gas Turbine ◽  
Spanwise Flow

This paper describes the design and development of a 15-stage axial flow compressor for a −6MW industrial gas turbine. Detailed aspects of the aerodynamic design are presented together with rig test data for the complete characteristic including stage data. Predictions of spanwise flow distributions are compared with measured values for the front stages of the compressor. Variable stagger stator blading is used to control the position of the low speed surge line and the effects of the stagger changes are discussed.

Endwall Effects at Two Tip Clearances in a Multistage Axial Flow Compressor With Controlled Diffusion Blading

1994 ◽  
Vol 116 (4) ◽  
pp. 635-645 ◽  
Author(s):  
M. A. Howard ◽  
P. C. Ivey ◽  
J. P. Barton ◽  
K. F. Young
Keyword(s):  
Unsteady Flow ◽  
Axial Flow ◽  
Tip Clearance ◽  
Exit Angle ◽  
Controlled Diffusion ◽  
The Third ◽  
Flow Phenomena ◽  
Multistage Compressor ◽  
Flow Compressor ◽  
Stage Efficiency

Effects of tip clearance, secondary flow, skew, and corner stall on the performance of a multistage compressor with controlled diffusion blading have been studied experimentally. Measurements between 1 and 99 percent annulus height were carried out in both the first and the third stages of a four-stage low-speed compressor with repeating-stage blading. Measurements were obtained at a datum rotor tip clearance and at a more aerodynamically desirable lower clearance. The consequences of the modified rotor tip clearance on both rotor and stator performance are examined in terms of loss coefficient and gas exit angle. Stator losses close to the casing are found to increase significantly when the clearance of an upstream rotor is increased. These increased stator losses cause 30 percent of the stage efficiency reduction that arises with increased rotor tip clearance. The deviation angles due to tip clearance from the multistage measurements are found to be similar to data from single-stage machines with conventional blading, which suggests that the unsteady flow phenomena associated with the multistage environment do not dominate the physics of the flow.

scholarly journals Optimum Control of Variable Components in Aircraft Gas Turbine Engines Under Non-Stationary Flow Disturbances at the Inlet

1994 ◽  
Author(s):  
I. N. Egorov ◽  
G. V. Kreitinin
Keyword(s):  
Gas Turbine ◽  
Dynamic Control ◽  
Axial Flow ◽  
Stationary Flow ◽  
Turbine Engines ◽  
Stable Operation ◽  
Turbine Engine ◽  
Axial Flow Compressor ◽  
Flow Disturbances ◽  
Flow Compressor

A numerical method has been preposed to determine optimum laws to control gas turbine engine (CTE) variable components, including an independent control of blade rows in a multistage axial flow compressor under strong non-stationary flow disturbances at the inlet, optimum laws to control a turbofan under non-stationary thermal effects at the inlet have been obtained using mathematical models with various degree of filling in detail the flow in an engine flow path. There is shown a possibility to considerably increase a range of the CTE stable operation through the use of dynamic control of stator blades in a multistage axial flow compressor, also possibilities of practical use of optimum laws to control engine variable components in the system of preventing an unstable operation are being discussed.

Optimization of Gas Turbine Engine Elements by Probability Criteria

1993 ◽  
Author(s):  
I. N. Egorov ◽  
G. V. Kretinin
Keyword(s):  
Stochastic Optimization ◽  
Gas Turbine ◽  
Axial Flow ◽  
Gas Turbine Engine ◽  
Design Parameters ◽  
Technical Object ◽  
Turbine Engine ◽  
Flow Compressor ◽  
Engine Components ◽  
Stochastic Setting

Procedure for the stochastic optimization of design parameters of gas turbine engine components for a prescribed level of production technology is discussed. Such combined criteria of the stochastic optimization as effectiveness-probability of realizing a design of an intricate technical object are proposed. With reference to the task of optimum designing the rows of a multistage axial flow compressor, there are presented the results, obtained for various probability criteria, in parallel with conducting their comparative analysis, and there are also investigated optimum stable (robust) characteristics of designs obtained for various levels of technology. There are also demonstrated a possibility of a significant increase in probability to realize in actual practice the design, obtained in stochastic setting, as compared to the design, obtained in deterministic setting.

Sign in / Sign up

Export Citation Format

Share Document