High-Fidelity Numerical Analysis of Per-Rev-Type Inlet Distortion Transfer in Multistage Fans—Part I: Simulations With Selected Blade Rows

2010 ◽  
Vol 132 (4) ◽  
Author(s):  
Jixian Yao ◽  
Steven E. Gorrell ◽  
Aspi R. Wadia
Keyword(s):  
Total Pressure ◽  
High Performance ◽  
Full Range ◽  
High Fidelity ◽  
Flow Distortion ◽  
Inlet Flow ◽  
Inlet Distortion ◽  
Depth Analysis ◽  
Total Temperature ◽  
Generation Mechanisms

Demands for improved performance and operability of advanced propulsion systems require an understanding of the physics of inlet flow distortion transfer and generation and the subsequent engine response. This also includes developing a high-fidelity characterization capability and suitable tools/rules for the design of distortion tolerant engines. This paper describes efforts to establish a high-fidelity prediction capability of distortion transfer and fan response via high-performance computing. The current CFD capability was evaluated with a focus of predicting the transfer of prescribed inlet flow distortions. Numerical simulations, comparison to experimental data, and analysis of two selected three-stage fans are presented. The unsteady Reynolds-Averaged Navier-Stokes (RANS) code PTURBO demonstrated remarkable agreement with data, accurately capturing both the magnitude and profile of total pressure and total temperature measurements. Part I of this paper describes the establishment of the required numerical simulation procedures. The computational domains are limited to the first three blade rows for the first multistage fan and the last three blade rows for the second fan. This paper presents initial validation and analysis of the total pressure distortion transfer and the total temperature distortion generation. Based on the established ground work of Part I, the entire two multistage fans were simulated with inlet distortion at normal operating condition and near stall condition, which is Part II of this paper. Part II presents the full range validation against engine test data and in-depth analysis of distortion transfer and generation mechanisms throughout the two fans.

High-Fidelity Numerical Analysis of Per-Rev-Type Inlet Distortion Transfer in Multistage Fans: Part I—Simulations With Selected Blade Rows

2008 ◽  
Author(s):  
Jixian Yao ◽  
Steven E. Gorrell ◽  
Aspi R. Wadia
Keyword(s):  
Total Pressure ◽  
High Performance ◽  
Full Range ◽  
High Fidelity ◽  
Flow Distortion ◽  
Inlet Flow ◽  
Inlet Distortion ◽  
Multi Stage ◽  
Depth Analysis ◽  
Total Temperature

Demands for improved performance and operability of advanced propulsion systems require an understanding of the physics of inlet flow distortion transfer and generation and the subsequent engine response. This also includes developing a high-fidelity characterization capability and suitable tools/rules for the design of distortion tolerant engines. This paper describes efforts to establish a high-fidelity prediction capability of distortion transfer and fan response via high-performance computing. The current CFD capability was evaluated with a focus of predicting the transfer of prescribed inlet flow distortions. Numerical simulations, comparison to experimental data, and analysis of two selected three-stage fans are presented. The unsteady RANS code Pturbo demonstrated remarkable agreement with data, accurately capturing both the magnitude and profile of total pressure and total temperature measurements. Part I of the paper describes the establishment of the required numerical simulation procedures. The computational domains are limited to the first three blade rows for the first multistage fan and the last three blade rows for the second fan. The paper presents initial validation and analysis of the total pressure distortion transfer and the total temperature distortion generation. Based on the established ground work of Part I, the entire two multi-stage fans were simulated with inlet distortion at normal operating condition and near stall condition, which is part II of the paper. Part II presents the full range validation against engine test data, and in-depth analysis of distortion transfer and generation mechanisms through out the two fans.

High-Fidelity Numerical Analysis of Per-Rev-Type Inlet Distortion Transfer in Multistage Fans—Part II: Entire Component Simulation and Investigation

2010 ◽  
Vol 132 (4) ◽  
Author(s):  
Jixian Yao ◽  
Steven E. Gorrell ◽  
Aspi R. Wadia
Keyword(s):  
Total Pressure ◽  
Navier Stokes ◽  
High Fidelity ◽  
Inlet Distortion ◽  
Unsteady Rans ◽  
Total Temperature ◽  
Computational Fluid Dynamics Cfd ◽  
Last Stage ◽  
Remarkable Agreement ◽  
Engine Development

Part I of this paper validated the ability of the unsteady Reynolds-Averaged Navier-Stokes (RANS) solver PTURBO to accurately simulate distortion transfer and generation through selected blade rows of two multistage fans. In this part, unsteady RANS calculations were successfully applied to predict the 1/rev inlet total pressure distortion transfer in the entirety of two differently designed multistage fans. This paper demonstrates that high-fidelity computational fluid dynamics (CFD) can be used early in the design process for verification purposes before hardware is built and can be used to reduce the number of distortion tests, hence reducing engine development cost. The unsteady RANS code PTURBO demonstrated remarkable agreement with the data, accurately capturing both the magnitude and the profile of total pressure and total temperature measurements. Detailed analysis of the flow physics identified from the CFD results has led to a thorough understanding of the total temperature distortion generation and transfer mechanism, especially for the spatial phase difference of total pressure and total temperature profiles. The analysis illustrates that the static parameters are more revealing than their stagnation counterpart and that pressure and temperature rise are more revealing while the pressure and temperature ratio could be misleading. The last stage is effectively throttled by the inlet distortion even though the overall engine throttle remains unchanged. The total temperature distortion generally grows as flow passes through the fan stages.

High-Fidelity Numerical Analysis of Per-Rev-Type Inlet Distortion Transfer in Multistage Fans: Part II—Entire Component Simulation and Investigation

2008 ◽  
Author(s):  
Jixian Yao ◽  
Steven E. Gorrell ◽  
Aspi R. Wadia
Keyword(s):  
Total Pressure ◽  
High Fidelity ◽  
Temperature Profiles ◽  
Inlet Distortion ◽  
Unsteady Rans ◽  
Total Temperature ◽  
Last Stage ◽  
The One ◽  
Remarkable Agreement ◽  
Engine Development

Part I of the paper validated the ability of the Unsteady RANS solve Pturbo to accurately simulate distortion transfer and generation through selected blade rows of two multistage fans. In part II, unsteady RANS calculations were successfully applied to predict the one-per-rev inlet total pressure distortion transfer in the entirety of two differently designed multistage fans. This paper demonstrates that Hi-Fi CFD can be used early in the design process for verification purposes before hardware is built, and can be used to reduce the number of distortion tests, hence reducing engine development cost. The unsteady RANS code Pturbo demonstrated remarkable agreement with data, accurately capturing both the magnitude and profile of total pressure and total temperature measurements. Detailed analysis of the flow physics identified from the CFD results has led to a thorough understanding of the total temperature distortion generation and transfer mechanism, especially for the spatial phase difference of total pressure and total temperature profiles. The analysis illustrates that the static parameters are more revealing than their stagnation counterpart and that pressure and temperature rise are more revealing while the pressure and temperature ratio could be misleading. The last stage is effectively throttled by the inlet distortion even though the overall engine throttle remains unchanged. The total temperature distortion generally grows as flow passes through the fan stages.

scholarly journals JET ENGINE INLET DISTORTION SCREEN AND DESCRIPTOR EVALUATION

2017 ◽  
Vol 57 (1) ◽  
pp. 22-31 ◽  
Author(s):  
Jiří Pečinka ◽  
Gabriel Thomas Bugajski ◽  
Petr Kmoch ◽  
Adolf Jílek
Keyword(s):  
Total Pressure ◽  
Basic Flow ◽  
Interface Plane ◽  
Inlet Channel ◽  
Flow Distortion ◽  
Turbine Engine ◽  
Inlet Distortion ◽  
Mass Flow Rates ◽  
Total Temperature ◽  
The University

Total pressure distortion is one of the three basic flow distortions (total pressure, total temperature and swirl distortion) that might appear at the inlet of a gas turbine engine (GTE) during operation. Different numerical parameters are used for assessing the total pressure distortion intensity and extent. These summary descriptors are based on the distribution of total pressure in the aerodynamic interface plane. There are two descriptors largely spread around the world, however, three or four others are still in use and can be found in current references. The staff at the University of Defence decided to compare the most common descriptors using basic flow distortion patterns in order to select the most appropriate descriptor for future department research. The most common descriptors were identified based on their prevalence in widely accessible publications. The construction and use of these descriptors are reviewed in the paper. Subsequently, they are applied to radial, angular, and combined distortion patterns of different intensities and with varied mass flow rates. The tests were performed on a specially designed test bench using an electrically driven standalone industrial centrifugal compressor, sucking air through the inlet of a TJ100 small turbojet engine. Distortion screens were placed into the inlet channel to create the desired total pressure distortions. Of the three basic distortions, only the total pressure distortion descriptors were evaluated. However, both total and static pressures were collected using a multi probe rotational measurement system.

Unsteady Three-Dimensional Analysis of Inlet Distortion in a Transonic Fan

2006 ◽  
Author(s):  
Peng Sun ◽  
Guotal Feng
Keyword(s):  
Shock Wave ◽  
Total Pressure ◽  
Large Scale ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Inlet Distortion ◽  
Flow Loss ◽  
Large Scale Vortex ◽  
Total Temperature ◽  
Transonic Fan

A time-accurate three-dimensional Navier-Stokes solver of the unsteady flow field in a transonic fan was carried out using "Fluent-parallel" in a parallel supercomputer. The numerical simulation focused on a transonic fan with inlet square wave total pressure distortion and the analysis of result consisted of three aspects. The first was about inlet parameters redistribution and outlet total temperature distortion induced by inlet total pressure distortion. The pattern and causation of flow loss caused by pressure distortion in rotor were analyzed secondly. It was found that the influence of distortion was different at different radial positions. In hub area, transportation-loss and mixing-loss were the main loss patterns. Distortion not only complicated them but enhanced them. Especially in stator, inlet total pressure distortion induced large-scale vortex, which produced backflow and increased the loss. While in casing area, distortion changed the format of shock wave and increased the shock loss. Finally, the format of shock wave and the hysteresis of rotor to distortion were analyzed in detail.

scholarly journals Investigation of Flows in Rectangular Diffusers With Inlet Flow Distortion

1982 ◽  
Author(s):  
M. M. Al-Mudhafar ◽  
M. Ilyas ◽  
F. S. Bhinder
Keyword(s):  
Experimental Study ◽  
Velocity Profiles ◽  
Pressure Recovery ◽  
Two Dimensional ◽  
Flow Distortion ◽  
Inlet Flow ◽  
Inlet Velocity ◽  
Inlet Distortion ◽  
Mach Numbers ◽  
Inlet Flow Distortion

The results of an experimental study on the influence of severely distorted velocity profiles on the performance of a straight two-dimensional diffuser are reported. The data cover entry Mach numbers ranging from 0.1 to 0.6 and several inlet distortion levels. The pressure recovery progressively deteriorates as the inlet velocity is distorted.

scholarly journals Experimental Investigation of Inlet Distortion Effect on Performance of a Micro Gas Turbine

2018 ◽  
Vol 140 (9) ◽  
Author(s):  
Alireza Naseri ◽  
Shervin Sammak ◽  
Masoud Boroomand ◽  
Alireza Alihosseini ◽  
Abolghasem M. Tousi
Keyword(s):  
Gas Turbine ◽  
Total Pressure ◽  
Nonuniform Flow ◽  
Inlet Flow ◽  
Micro Gas Turbine ◽  
Inlet Distortion ◽  
Air Jet ◽  
Measuring Devices ◽  
Turbine Performance ◽  
Distortion Effect

An experimental study has been carried out to determine how inlet total-pressure distortion affects the performance of a micro gas turbine. An inlet simulator is designed and developed to produce and measure distortion patterns at the inlet to the gas turbine. An air jet distortion generator (AJDG) is used to produce nonuniform flow patterns and total pressure probes are installed to measure steady-state total-pressure distribution at the inlet. A set of wind tunnel tests have been performed to confirm the fidelity of distortion generator and measuring devices. Tests are carried out with the gas turbine exposed to inlet flow with 60 deg, 120 deg, and 180 deg circumferential distortion patterns with different distortion intensities. The performance of the gas turbine has been measured and compared with that of clean inlet flow case. Results indicate that the gas turbine performance can be affected significantly facing with intense inlet distortions.

Unsteady Computational Fluid Dynamics Investigation on Inlet Distortion in a Centrifugal Compressor

2010 ◽  
Vol 132 (3) ◽  
Author(s):  
Armin Zemp ◽  
Albert Kammerer ◽  
Reza S. Abhari
Keyword(s):  
Centrifugal Compressor ◽  
Temporal Evolution ◽  
Flow Distribution ◽  
Forced Response ◽  
Inlet Section ◽  
Flow Distortion ◽  
Inlet Flow ◽  
Inlet Distortion ◽  
Forcing Function ◽  
Unsteady Fluid

Blade failure in turbomachinery is frequently caused by an excessive resonant response. Forced response of the blades originates from unsteady fluid structure interactions as conditioned in the inlet section by duct bends, struts, or inlet guide vanes. This paper presents the computational part of a research effort that focuses on the blade forced response in a centrifugal compressor. Unsteady fluid flow simulations are used to quantify the forcing function acting on the compressor blades due to inlet flow distortion. The measured inlet flow distribution is applied as inlet boundary conditions in the computation. The unsteady investigation provided the temporal evolution of the distorted flow through the compressor. The time-resolved blade pressure distribution showed the temporal evolution of the dynamic load on the blade surface caused by the inlet distortion. The results suggest that the forcing function is most sensitive in the leading edge region due to inlet angle variations. Toward the impeller stability line the increase in incidence caused separation on the suction side of the main blade and therefore considerably altered the amplitude and the phase angle of the unsteadiness. The investigation of the effect of idealizing the inlet flow distribution on the forcing function showed an increase in the peak amplitude of approximately 30% compared with the actual inlet flow distribution.

Unsteady CFD Investigation on Inlet Distortion in a Centrifugal Compressor

2008 ◽  
Author(s):  
Armin Zemp ◽  
Albert Kammerer ◽  
Reza S. Abhari
Keyword(s):  
Centrifugal Compressor ◽  
Temporal Evolution ◽  
Flow Distribution ◽  
Forced Response ◽  
Inlet Section ◽  
Flow Distortion ◽  
Inlet Flow ◽  
Inlet Distortion ◽  
Forcing Function ◽  
Unsteady Fluid

Blade failure in turbomachinery is frequently caused by an excessive resonant response. Forced response of the blades originates from unsteady fluid structure interactions as conditioned in the inlet section by duct bends, struts or inlet guide vanes. This paper presents the computational part of a research effort that focuses on the blade forced response in a centrifugal compressor. Unsteady fluid flow simulations are used to quantify the forcing function acting on the compressor blades due to inlet flow distortion. The measured inlet flow distribution is applied as inlet boundary conditions in the computation. The unsteady investigation provided the temporal evolution of the distorted flow through the compressor. The time-resolved blade pressure distribution showed the temporal evolution of the dynamic load on the blade surface caused by the inlet distortion. The results suggest that the forcing function is most sensitive in the leading edge region due to inlet angle variations. Towards the impeller stability line the increase in incidence caused separation on the suction side of the main blade and therefore considerably altered the amplitude and the phase angle of the unsteadiness. The investigation of the effect of idealizing the inlet flow distribution on the forcing function showed an increase of the peak amplitude of approximately 30% compared to the actual inlet flow distribution.

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