Steady Performance Measurements of a Turbofan Engine With Inlet Distortions Containing Co- and Counterrotating Swirl From an Intake Diffuser for Hypersonic Flight

2000 ◽  
Vol 123 (2) ◽  
pp. 379-385 ◽  
Author(s):  
Norbert R. Schmid ◽  
Dirk C. Leinhos ◽  
Leonhard Fottner
Keyword(s):  
Low Frequency ◽  
Engine Performance ◽  
Propulsion System ◽  
Performance Measurements ◽  
Turbofan Engine ◽  
Frequency Measurements ◽  
Hypersonic Aircraft ◽  
Inhomogeneous Flow ◽  
Left And Right ◽  
Axisymmetric Mirror

The influence of distorted inlet flow on the steady and unsteady performance of a turbofan engine, which is a component of an air-breathing combined propulsion system for a hypersonic transport aircraft, is reported in this paper. The performance and stability of this propulsion system depend on the behavior of the turbofan engine. The complex shape of the intake duct causes inhomogeneous flow at the engine inlet plane, where total pressure and swirl distortions are present. The S-bend intakes are installed axisymmetrically left and right into the hypersonic aircraft, generating axisymmetric mirror-inverted flow patterns. Since all turbo engines of the propulsion system have the same direction of rotation, one distortion corresponds to a corotating swirl at the low pressure compressor (LPC) inlet while the mirror-inverted image counterpart represents a counterrotating swirl. Therefore the influence of the distortions on the performance and stability of the ‘CO’ and ‘COUNTER’ rotating turbo engine are different. The distortions were generated separately by an appropriate simulator at the inlet plane of a LARZAC 04 engine. The results of low-frequency measurements at different engine planes yield the relative variations of thrust and specific fuel consumption and hence the steady engine performance. High-frequency measurements were used to investigate the different influence of CO and COUNTER inlet distortions on the development of LPC instabilities.

Steady Performance Measurements of a Turbofan Engine With Inlet Distortions Containing Co- and Counter-Rotating Swirl From an Intake Diffuser for Hypersonic Flight

2000 ◽  
Author(s):  
Norbert R. Schmid ◽  
Dirk C. Leinhos ◽  
Leonhard Fottner
Keyword(s):  
Low Frequency ◽  
Engine Performance ◽  
Propulsion System ◽  
Performance Measurements ◽  
Turbofan Engine ◽  
Frequency Measurements ◽  
Hypersonic Aircraft ◽  
Inhomogeneous Flow ◽  
Left And Right ◽  
Unsteady Performance

The influence of distorted inlet flow on the steady and unsteady performance of a turbofan engine which is a component of an airbreathing combined propulsion system for a hypersonic transport aircraft is reported in this paper. The performance and stability of this propulsion system depends on the behavior of the turbofan engine. The complex shape of the intake duct causes inhomogeneous flow at the engine inlet plane, where total pressure and swirl distortions are present. The S-bend intakes are installed axisymmetrically left and right into the hypersonic aircraft hence generating axisymmetrical mirror inverted flow patterns. Since all turbo engines of the propulsion system have the same direction of rotation, one distortion corresponds to a co-rotating swirl at the low pressure compressor (LPC) inlet while the mirror inverted image counterpart represents a counter-rotating swirl. Therefore the influence of the distortions on the performance and stability of the ‘CO’ and ‘COUNTER’ rotating turbo engine are differing, respectively. Both distortions were generated separately by an appropriate simulator at the inlet plane of a LARZAC 04 engine. The results of low frequency measurements at different engine planes yield the relative variations of thrust and specific fuel consumption and hence the steady engine performance. High frequency measurements were used to investigate the different influence of CO and COUNTER inlet distortions on the development of LPC instabilities.

scholarly journals A Method of Sizing Multi-Cycle Engines for Hypersonic Aircraft

1990 ◽  
Vol 112 (2) ◽  
pp. 217-222
Author(s):  
J. J. Kolden
Keyword(s):  
Iterative Procedure ◽  
Engine Performance ◽  
Computer Code ◽  
Propulsion System ◽  
Hypersonic Vehicles ◽  
Trade Off ◽  
Hypersonic Aircraft ◽  
Engine Size ◽  
Engine Cycle

A method of sizing multi-cycle engines for integration with hypersonic vehicles has been developed. The new procedure independently sizes the inlet, each engine cycle, and the nozzle during the vehicle sizing loop to optimize propulsion/aircraft integration. Using uninstalled engine performance for each cycle of a multi-cycle engine along with inlet and nozzle performance and an estimate of aircraft drag, an iterative procedure is utilized to size each component simultaneously. A propulsion system is defined that meets the aircraft thrust requirements at all mission points. The inlet is sized to provide airflow such that the maximum Mach cruise and/or combat thrust conditions are met. Each cycle is sized independently to meet all thrust requirements while minimizing either inlet drag or engine size. Nozzle sizing must trade off thrust, drag and nozzle weight. This methodology has been incorporated into a computer code entitled “Multi-Cycle Engine Sizing Program,” MCESP.

scholarly journals A Method of Sizing Multi-Cycle Engines for Hypersonic Aircraft

1989 ◽  
Author(s):  
Jennifer J. Kolden
Keyword(s):  
Iterative Procedure ◽  
Engine Performance ◽  
Computer Code ◽  
Propulsion System ◽  
Hypersonic Vehicles ◽  
Trade Off ◽  
Hypersonic Aircraft ◽  
Engine Size ◽  
Engine Cycle

A method of sizing multi-cycle engines for integration with hypersonic vehicles has been developed. The new procedure independently sizes the inlet, each engine cycle, and the nozzle during the vehicle sizing loop to optimize propulsion/aircraft integration. Using uninstalled engine performance for each cycle of a multi-cycle engine along with inlet and nozzle performance and an estimate of aircraft drag, an iterative procedure is utilized to size each component simultaneously. A propulsion system is defined that meets the aircraft thrust requirements at all mission points. The inlet is sized to provide airflow such that the maximum Mach cruise and/or combat thrust conditions are met. Each cycle is sized independently to meet all thrust requirements while either minimizing inlet drag or engine size. Nozzle sizing must trade-off thrust, drag and nozzle weight. This methodology has been incorporated into a computer code entitled “Multi-Cycle Engine Sizing Program”, MCESP.

Mechanical monolithic tiltmeter for low frequency measurements

2012 ◽  
Author(s):  
F. Acernese ◽  
R. Canonico ◽  
R. De Rosa ◽  
G. Giordano ◽  
R. Romano ◽  
...  
Keyword(s):  
Low Frequency ◽  
Frequency Measurements

A Flight Simulation Vision for Aeropropulsion Altitude Ground Test Facilities

2005 ◽  
Vol 127 (1) ◽  
pp. 8-17 ◽  
Author(s):  
Milt Davis ◽  
Peter Montgomery
Keyword(s):  
System Performance ◽  
Engine Performance ◽  
Aircraft Engine ◽  
Flight Simulation ◽  
Propulsion System ◽  
Test Facility ◽  
Flight Testing ◽  
Test Environment ◽  
Ground Test ◽  
Aircraft System

Testing of a gas turbine engine for aircraft propulsion applications may be conducted in the actual aircraft or in a ground-test environment. Ground test facilities simulate flight conditions by providing airflow at pressures and temperatures experienced during flight. Flight-testing of the full aircraft system provides the best means of obtaining the exact environment that the propulsion system must operate in but must deal with limitations in the amount and type of instrumentation that can be put on-board the aircraft. Due to this limitation, engine performance may not be fully characterized. On the other hand, ground-test simulation provides the ability to enhance the instrumentation set such that engine performance can be fully quantified. However, the current ground-test methodology only simulates the flight environment thus placing limitations on obtaining system performance in the real environment. Generally, a combination of ground and flight tests is necessary to quantify the propulsion system performance over the entire envelop of aircraft operation. To alleviate some of the dependence on flight-testing to obtain engine performance during maneuvers or transients that are not currently done during ground testing, a planned enhancement to ground-test facilities was investigated and reported in this paper that will allow certain categories of flight maneuvers to be conducted. Ground-test facility performance is simulated via a numerical model that duplicates the current facility capabilities and with proper modifications represents planned improvements that allow certain aircraft maneuvers. The vision presented in this paper includes using an aircraft simulator that uses pilot inputs to maneuver the aircraft engine. The aircraft simulator then drives the facility to provide the correct engine environmental conditions represented by the flight maneuver.

Analysis of Effect of Advanced Technique Configurations on Overall Performance of High Bypass Turbofan Engine

2014 ◽  
Author(s):  
Liu Jian Jun
Keyword(s):  
Air Flow ◽  
Engine Performance ◽  
Performance Model ◽  
Direct Drive ◽  
Nozzle Throat ◽  
Advanced Technique ◽  
Turbofan Engine ◽  
Overall Performance ◽  
Cooling Air Flow ◽  
Cooling Air

An analytical study was undertaken using the performance model of a two spool direct drive high BPR 300kN thrust turbofan engine, to investigate the effects of advanced configurations on overall engine performance. These include variable bypass nozzle, variable cooling air flow and more electric technique. For variable bypass nozzle, analysis on performance of outer fan at different conditions indicates that different operating points cannot meet optimal performance at the same time if the bypass nozzle area kept a constant. By changing bypass nozzle throat area at different states, outer fan operating point moves to the location where airflow and efficiency are more appropriate, and have enough margin away from surge line. As a result, the range of variable area of bypass nozzle throat is determined which ensures engine having a low SFC and adequate stability. For variable cooling airflow, configuration of turbine cooling air flow extraction and methodology for obtaining change of cooling airflow are investigated. Then, base on temperature analysis of turbine vane and blade and resistance of cooling airflow, reduction of cooling airflow is determined. Finally, using performance model which considering effect of cooling air flow on work and efficiency of turbine, variable cooling airflow effect on overall performance is analyzed. For more electric technique, the main characteristic is to use power off-take instead of overboard air extraction. Power off-take and air extraction effect on overall performance of high bypass turbofan engine is compared. Investigation demonstrates that power offtake will have less SFC.

Physical Parameters for Four Seabed Geoacoustic Models from Low-Frequency Measurements

2010 ◽  
Author(s):  
Ji-Xun Zhou ◽  
Xue-Zhen Zhang ◽  
Jeffrey Simmen ◽  
Ellen S. Livingston ◽  
Ji-Xun Zhou ◽  
...  
Keyword(s):  
Low Frequency ◽  
Physical Parameters ◽  
Frequency Measurements
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