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.

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.

Wind-tunnel tests of the ERICA tiltrotor optimised air-intake

2018 ◽  
Vol 122 (1251) ◽  
pp. 821-837
Author(s):  
G. Gibertini ◽  
A. Zanotti ◽  
G. Campanardi ◽  
F. Auteri ◽  
D. Zagaglia ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
Total Pressure ◽  
Internal Surface ◽  
Scale Model ◽  
Interface Plane ◽  
Shape Optimisation ◽  
Duct Flow ◽  
Flow Distortion ◽  
Wind Tunnel Tests ◽  
Air Intake

ABSTRACTWind-tunnel tests were carried out to evaluate the performance of the Computational Fluid Dynamics (CFD)-based air-intake duct shape optimisation of the European platform tiltrotor ERICA. A 1/2.5 scale model including the nacelle, the external portion of the wing and two interchangeable internal ducts reproducing the baseline and optimised shape were manufactered to be tested in the large wind tunnel of Politecnico di Milano. Moreover, tests were carried out with the model equipped with rotating blade stubs. The comprehensive experimental campaign included tests reproducing different forward flight conditions of the aircraft including cruise and conversion phases. The evaluation of the internal duct performance was carried out by measuring total pressure losses and flow distortion by directional probes at the Aerodynamic Interface Plane (AIP). Additional pressure measurements were carried out on the internal surface of the duct to compare the pressure distributions along the air-intake. The experimental results confirmed that the optimised duct offers significantly improved performance with respect to the baseline configuration not only in cruise, representing the flight condition considered for the CFD optimisation, but also for the conversion condition. In particular, a remarkable reduction of the total pressure drop at the AIP was found with the optimised duct with the only exception for the stubs-on configuration in cruise. Indeed, the present investigation highlighted that the design of the blade stubs, particularly their length, represents a very critical aspect for air-intake performance tests due to significant disturbances that could be induced by the stubs’ wake on the internal duct flow.

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.

Pre-Test Evaluation of Probe Configuration Errors

2019 ◽  
Author(s):  
John Gillespie ◽  
Dustin Frohnapfel ◽  
Walter O’Brien
Keyword(s):  
Total Pressure ◽  
Flow Property ◽  
Test Time ◽  
Test Evaluation ◽  
Flow Profile ◽  
Flow Distortion ◽  
Turbine Engine ◽  
Point To Point ◽  
The Cost ◽  
The Impact

Abstract Rake probes are commonly used in turbomachinery applications to measure distorted inlet flows, including both pressure and swirl distortions. An especially common configuration is the 40 probe rake array, consisting of eight identical arms equally spaced circumferentially around the inlet, each arm having five sensing locations spaced along centers of equal area. By measuring many locations simultaneously, rake probes have the advantage of expedited data collection when compared to traversing probes. However, this reduction in test time comes at the cost of rigid geometry with limited measurement locations. As a result, it is possible for rake probes to miss or exaggerate significant areas of the flow profile, such as large gradients or small features, based on the fixed location of the probe and the particular details of the distortion. The purpose of this paper is to demonstrate a procedure that can be used to evaluate the ability of any desired probe configuration (40 probe rake or otherwise) to sufficiently and accurately measure a non-uniform flow profile. Results of this procedure for a range of profiles and probe configurations are also presented. In order to accurately determine the impact of discrete sampling on the results, two broad sets of data were generated numerically and analyzed. The first set consists of four fundamental total pressure distortions: once-per-rev circumferential, twice-per-rev circumferential, hub radial, and tip radial. The second set consists of three realistic turbofan distortion patterns: two analytic (though not fundamental) profiles, and one generated from S-duct computational results. For all investigated patterns, Radial Distortion Intensity and Circumferential Distortion Intensity are calculated in the manner described by ARP 1420, a guideline issued by the S-16 Turbine Engine Inlet Flow Distortion Committee for measuring total pressure distortions in turbomachinery. Additionally, interpolated total pressure contours are generated for each measurement configuration. These were then used to make point-to-point comparisons between the actual and estimated data. While total pressure distortion was used as the variable of interest for the majority of this paper, the conclusions may be applied to swirl, temperature, or any other flow property measured using a probe rake or traversing probe.

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.

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