The Effect of Inlet Flow Distortion on Performance of a Micro-Jet Engine: Part 2 — Engine Tests

2012 ◽  
Author(s):  
A. Naseri ◽  
M. Boroomand ◽  
A. M. Tousi ◽  
A. R. Alihosseini
Keyword(s):  
Steady State ◽  
Total Pressure ◽  
Engine Performance ◽  
Flow Distortion ◽  
Inlet Flow ◽  
Jet Engine ◽  
Turbine Engine ◽  
Air Jet ◽  
Engine Part ◽  
Inlet Flow Distortion

This paper concerns investigating effect of inlet flow distortion on performance of a micro-jet engine. An experimental study has been carried out to determine how the steady state inlet total-pressure distortion affects the performance of a micro gas turbine engine. An inlet simulator is designed and developed to produce and measure distortion patterns at the engine inlet. An Air Jet Distortion Generator is used to produce non-uniform flow patterns and total pressure probes are implemented to measure steady state total pressure distribution at the engine face. A set of wind tunnel tests has been performed to confirm the fidelity of distortion generator and measuring devices. The engine got exposed to inlet flow with 60-degree, 120-degree, and 180-degree circumferential distortion patterns with different distortion intensities and the engine performance have been measured and compared with that of clean inlet flow. Results indicate that engine performance can be affected significantly facing with intense inlet distortions.

The Effect of Inlet Flow Distortion on Performance of a Micro-Jet Engine: Part 1 — Development of an Inlet Simulator

2012 ◽  
Author(s):  
A. Naseri ◽  
M. Boroomand ◽  
A. M. Tousi
Keyword(s):  
Wind Tunnel ◽  
Total Pressure ◽  
Engine Performance ◽  
Flow Distortion ◽  
Inlet Flow ◽  
Jet Engine ◽  
Wind Tunnel Tests ◽  
Turbine Engine ◽  
Air Jet ◽  
Air Supply

This paper represents the development of an inlet simulator to produce and measure steady state total-pressure distortion at the inlet of a micro-jet engine. Different methods of distortion generation and engine testing are discussed and the developed system is described. The developed inlet simulator device consists of a direct connecting air supply duct, a distortion generator unit inside the duct ahead of the engine inlet, and a matrix of total pressure probes at the end of the duct and close to engine entry. An Air Jet Distortion Generator is designed and developed to produce desired distortion patterns at the engine face. A series of wind tunnel tests has been carried out to verify the ability of the system to simulate various inlet flow conditions. Circumferential patterns with 60, 120 and 180 degree distorted zones with different distortion intensities were produced during wind tunnel tests. Measured distortion patterns are represented and the proper operation of the system in wind tunnel is discussed and proved. The inlet simulator then get installed on a micro gas turbine engine and distortion patterns has been produced and measured at the engine inlet during engine performance tests. Measured patterns at the engine inlet and the engine responses are represented.

Effects of Inlet Flow Distortion on the Performance of Aircraft Gas Turbines

2008 ◽  
Vol 130 (4) ◽  
Author(s):  
Joachim Kurzke
Keyword(s):  
Control System ◽  
Gas Turbines ◽  
System Simulation ◽  
Engine Performance ◽  
Thermodynamic Cycle ◽  
Operating Conditions ◽  
Flow Distortion ◽  
Inlet Flow ◽  
Inlet Flow Distortion ◽  
The Impact

This paper describes how the fundamental effects of inlet flow distortion on the performance of gas turbines can be evaluated with any engine performance program that employs an integrated parallel compressor model. In this simulation method, both pressure and temperature distortions are quantified with coefficients, which relate the pressure (respectively temperature) in the spoiled sector to the value in the clean sector. In single spool compressor engines, the static pressure at the exit of the clean sector equals that of the distorted sector. This hypothesis does not hold true with multispool compressor engines because the short intercompressor ducts, which often contain struts or vanes, do not allow the mass flow transfer over the sector borders, which would be required for balancing the static pressures. The degree of aerodynamic coupling of compressors in series can be described in the performance simulation program by the simple coupling factor introduced in this paper. There are two fundamentally different reasons for the change in engine performance: First, there is the impact of the flow distortion on the component efficiencies and thus the thermodynamic cycle and second there are performance changes due to the actions of the control system. From the engine system simulation results, it becomes clear why inlet flow distortion has only a minor impact on the thermodynamic cycle if the comparison of the two operating conditions (with clean and distorted inlet flow) is made at the properly averaged engine inlet conditions. For each compressor, the parallel compressor theory yields two operating points in the map, one for the clean sector and one for the spoiled sector. The performance loss due to the distortion is small since the efficiency values in the two sectors are only a bit lower than the efficiency at a comparable operating point with clean inlet flow. However, the control system of the engine can react to the inlet flow distortion in such a way that the thrust delivered changes significantly. This is particularly true if a compressor bleed valve or a variable area nozzle is opened to counteract compressor stability problems. Especially, using recirculating bleed air for increasing the surge margin of a compressor affects the performance of the engine negatively. Two examples show clearly that the pros and cons of recirculating bleed can only be judged with a full system simulation; looking at the surge line improvement alone can be misleading.

Prediction of Engine Performance Under Compressor Inlet Flow Distortion Using Streamline Curvature

2006 ◽  
Author(s):  
Vassilios Pachidis ◽  
Pericles Pilidis ◽  
Ioannis Templalexis ◽  
Theodosios Alexander ◽  
Petros Kotsiopoulos
Keyword(s):  
Three Dimensional ◽  
Engine Performance ◽  
Radial Pressure ◽  
Two Dimensional ◽  
Component Level ◽  
Flow Distortion ◽  
Inlet Flow ◽  
Streamline Curvature ◽  
Inlet Flow Distortion ◽  
Inlet Conditions

Traditionally, engine performance has been simulated based on non-dimensional maps for compressors and turbines. Component characteristic maps assume by default a given state of inlet conditions which can not be easily altered in order to simulate two-dimensional or three-dimensional flow phenomena. Inlet flow distortion, for example, is usually simulated by applying empirical correction factors and modifiers to default component characteristics, alternatively, the parallel compressor theory may be applied. The accuracy of the above methods has been rather questionable since they are unable to capture in sufficient fidelity component-level, complex physical processes and analyze them in the context of the whole engine performance. The technique described in this paper integrates a zero-dimensional (non-dimensional) gas turbine modeling and performance simulation system and a two-dimensional, streamline curvature compressor software. The two-dimensional compressor software can fully define the characteristics of a compressor at several operating condition and is subsequently used in the zero-dimensional cycle analysis to provide a more accurate, physics-based estimate of compressor performance under clean and distorted inlet conditions, replacing the default compressor maps. The high-fidelity component communicates with the lower fidelity cycle via a fully automatic and iterative process for the determination of the correct operating point. This study discusses in detail the development, validation and integration of the two-dimensional, streamline curvature compressor software and presents the various loss models used in the code. It also discusses the relative changes in the performance of a two-stage, experimental compressor with different types of radial pressure distortion obtained by running the two-dimensional streamline curvature compressor software independently. Moreover, the performance of a notional engine model, utilizing the coupled, two-dimensional compressor, under distorted conditions is discussed in detail and compared against the engine performance under clean conditions.

Prediction of Engine Performance Under Compressor Inlet Flow Distortion Using Streamline Curvature

2006 ◽  
Vol 129 (1) ◽  
pp. 97-103 ◽  
Author(s):  
Vassilios Pachidis ◽  
Pericles Pilidis ◽  
Ioannis Templalexis ◽  
Theodosios Korakianitis ◽  
Petros Kotsiopoulos
Keyword(s):  
Engine Performance ◽  
Two Dimensional ◽  
Physical Processes ◽  
Flow Distortion ◽  
Inlet Flow ◽  
Streamline Curvature ◽  
Simulation Strategy ◽  
Flow Phenomena ◽  
Inlet Flow Distortion ◽  
Inlet Conditions

Traditionally, engine performance has been simulated based on nondimensional maps for compressors and turbines. Component characteristic maps assume by default a given state of inlet conditions that cannot be easily altered in order to simulate two- or three-dimensional flow phenomena. Inlet flow distortion, for example, is usually simulated by applying empirical correction factors and modifiers to default component characteristics. Alternatively, the parallel compressor theory may be applied. The accuracy of the above methods has been rather questionable over the years since they are unable to capture in sufficient fidelity component-level, complex physical processes and analyze them in the context of the whole engine performance. The technique described in this paper integrates a zero-dimensional (nondimensional) gas turbine modelling and performance simulation system and a two-dimensional, streamline curvature compressor software. The two-dimensional compressor software can fully define the characteristics of any compressor at several operating conditions and is subsequently used in the zero-dimensional cycle analysis to provide a more accurate, physics-based estimate of compressor performance under clean and distorted inlet conditions, replacing the default compressor maps. The high-fidelity, two-dimensional compressor component communicates with the lower fidelity cycle via a fully automatic and iterative process for the determination of the correct operating point. This manuscript firstly gives a brief overview of the development, validation, and integration of the two-dimensional, streamline curvature compressor software with the low-fidelity cycle code. It also discusses the relative changes in the performance of a two-stage, experimental compressor with different types of radial pressure distortion obtained by running the two-dimensional streamline curvature compressor software independently. Moreover, the performance of a notional engine model, utilizing the coupled, two-dimensional compressor, under distorted conditions is discussed in detail and compared against the engine performance under clean conditions. In the cases examined, the analysis carried out by this study demonstrated relative changes in the simulated engine performance larger than 1%. This analysis proves the potential of the simulation strategy presented in this paper to investigate relevant physical processes occurring in an engine component in more detail, and to assess the effects of various isolated flow phenomena on overall engine performance in a timely and affordable manner. Moreover, in contrast to commercial computational fluid dynamics tools, this simulation strategy allows in-house empiricism and expertise to be incorporated in the flow-field calculations in the form of deviation and loss models.

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