Turbine Engine Icing Spray Bar Design Issues

1994 ◽  
Author(s):  
C. Scott Bartlett
Keyword(s):  
Supercooled Liquid ◽  
Propulsion System ◽  
Test Facility ◽  
Turbine Engine ◽  
Turbofan Engines ◽  
Free Jet ◽  
Spray System ◽  
Key Issues ◽  
Development Center ◽  
High Thrust

Techniques have been developed at the Engine Test Facility (ETF) of the Arnold Engineering Development Center (AEOC) to simulate flight through atmospheric icing conditions of supercooled liquid water droplets. Ice formed on aircraft and propulsion system surfaces during flight through icing conditions can, even in small amounts, be extremely hazardous. The effects of ice are dependent on many variables and are still unpredictable. Often, experiments are conducted to determine the characteristics of the aircraft and its propulsion system in an icing environment. Facilities at the ETF provide the capability to conduct icing testing in either the direct-connect (connected pipe) or the free-jet mode. The requirements of a spray system for turbine engine icing testing are described, as are the techniques used at the AEDC ETF to simulate flight in icing conditions. Some of the key issues facing the designer of a spray system for use in an altitude facility are identified and discussed, and validation testing of the design of a new spray system for the AEDC ETF is detailed. This spray system enables testing of the newest generation of high-thrust turbofan engines in simulated icing conditions.

Turbine Engine Icing Spray Bar Design Issues

1995 ◽  
Vol 117 (3) ◽  
pp. 406-412 ◽  
Author(s):  
C. S. Bartlett
Keyword(s):  
Supercooled Liquid ◽  
Propulsion System ◽  
Test Facility ◽  
Turbine Engine ◽  
Turbofan Engines ◽  
Free Jet ◽  
Spray System ◽  
Key Issues ◽  
Development Center ◽  
High Thrust

Techniques have been developed at the Engine Test Facility (ETF) of the Arnold Engineering Development Center (AEDC) to simulate flight through atmospheric icing conditions of supercooled liquid water droplets. Ice formed on aircraft and propulsion system surfaces during flight through icing conditions can, even in small amounts, be extremely hazardous. The effects of ice are dependent on many variables and are still unpredictable. Often, experiments are conducted to determine the characteristics of the aircraft and its propulsion system in an icing environment. Facilities at the ETF provide the capability to conduct icing testing in either the direct-connect (connected pipe) or the free-jet mode. The requirements of a spray system for turbine engine icing testing are described, as are the techniques used at the AEDC ETF to simulate flight in icing conditions. Some of the key issues facing the designer of a spray system for use in an altitude facility are identified and discussed, and validation testing of the design of a new spray system for the AEDC ETF is detailed. This spray system enables testing of the newest generation of high-thrust turbofan engines in simulated icing conditions.

Development of a Freejet Capability for Evaluating Inlet-Engine Compatibility

1991 ◽  
Author(s):  
P. V. Maywald ◽  
D. K. Beale
Keyword(s):  
Technology Development ◽  
Support Systems ◽  
Supersonic Nozzle ◽  
Test Facility ◽  
Nozzle Flow ◽  
Propulsion Systems ◽  
Turbine Engine ◽  
Development Center ◽  
Subsonic Nozzle

The Arnold Engineering Development Center (AEDC) is installing a freejet test capability into the Aero-propulsion Systems Test Facility (ASTF). The freejet will provide the capability for ground determination of turbine engine and aircraft inlet compatibility by utilizing full-scale inlets and engines as test articles in a simulated flight environment. The details of the design, installation, and projected testing capability are described for a 57 ft2 supersonic nozzle and a 77 ft2 subsonic nozzle. Support systems for mechanically pitching and yawing the freejet nozzles are also reported as well as the test cell hardware for capturing the freejet nozzle flow. The plans for demonstrating the freejet capability prior to its initial operational date are explained. The technology development efforts to validate and utilize the freejet test capabilities are also described.

Investigation of the Effects of Inlet Swirl on Compressor Performance and Operability Using a Modified Parallel Compressor Model

2011 ◽  
Author(s):  
Nicholas Fredrick ◽  
Milt Davis
Keyword(s):  
Experimental Data ◽  
Total Pressure ◽  
Engine Performance ◽  
Propulsion System ◽  
Turbine Engine ◽  
Turbofan Engines ◽  
Inlet Distortion ◽  
Inlet Swirl ◽  
Engine Compressor ◽  
Compressor Performance

Serpentine ducts used by both military and commercial aircraft can generate significant flow angularity and total pressure distortion at the engine face. Most low by-pass ratio turbofan engines with mixed exhaust are equipped with inlet guide vanes (IGV) which can reduce the effect of moderate inlet distortion. High by-pass ratio and some low by-pass ratio turbofan engines are not equipped with IGVs, and swirl can in effect change the angle of attack of the fan blades. Swirl and total pressure distortion at the engine inlet will impact engine performance, operability, and durability. The impact on the engine performance and operability must be quantified to ensure safe operation of the aircraft and propulsion system. Testing is performed at a limited number of discrete points inside the propulsion system flight envelope where it is believed the engine is most sensitive to the inlet distortion in order to quantify these effects. Turbine engine compressor models are based on the limited amount of experimental data collected during testing. These models can be used as an analysis tool to improve the effectiveness of engine testing and to improve understanding of engine response to inlet distortion. The Dynamic Turbine Engine Compressor Code (DYNTECC) utilizes parallel compressor theory and quasi-one-dimensional Euler equations to determine compressor performance. In its standard form, DYNTECC uses user supplied characteristic stage maps in order to calculate stage forces and shaft work for use in the momentum and energy equations. These maps were typically developed using experimental data or created using characteristic codes such as the 1-D Mean Line Code (MLC) or the 2-D Streamline Curvature Code. The MLC was created to calculate the performance of individual compressor stages and requires less computational effort than the 2-D and 3-D models. To improve efficiency and accuracy, the MLC has been incorporated into DYNTECC as a subroutine. Rather than independently developing stage maps using the MLC and then importing these maps into DYNTECC, DYNTECC can now use the MLC to develop the required stage characteristic for the desired operating point. This will reduce time and complexity required to analyze the effects of inlet swirl on compressor performance. The combined DYNTECC/MLC was used in the past to model total pressure distortion. This paper presents the result obtained using the combined DYNTECC/MLC to model the effects of various types of inlet swirl on F109 fan performance and operability for the first time.

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.

Total Temperature Based Correction of the Turbulence Production in Hot Jets

2017 ◽  
Author(s):  
Jens Truemner ◽  
Christian Mundt
Keyword(s):  
Shear Layers ◽  
Efficiency Gain ◽  
Potential Core ◽  
Production Term ◽  
Turbofan Engines ◽  
Free Jet ◽  
Rans Models ◽  
Total Temperature ◽  
Turbulence Production ◽  
Good Agreement

Comparisons with experiments have shown that RANS models tend to underpredict the mixing process in shear layers with strong temperature gradients. In the modeling of jet engine’s exhaust systems this leads to an overpredicted potential core length and underestimated turbulence intensity in the free jet. In addition, the calculated efficiency gain is lower than indicated by measurements in mixed turbofan engines. Based on the findings from scale-resolving simulations a correction to the turbulence production term is proposed and compared with two NASA-experiments on hot jets. This correction is implemented in a Reynolds-stress and a k-ε model. The results are in very good agreement with the experimental data.

The Effect of Heat Transfer Coefficient Increase on Tip Clearance Control in H.P. Compressors in Gas Turbine Engine

2013 ◽  
Author(s):  
Godwin Ita Ekong ◽  
Christopher A. Long ◽  
Peter R. N. Childs
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Gas Turbine ◽  
Time Constant ◽  
Gas Turbine Engine ◽  
Operating Conditions ◽  
Tip Clearance ◽  
Test Facility ◽  
Turbine Engine

Compressor tip clearance for a gas turbine engine application is the radial gap between the stationary compressor casing and the rotating blades. The gap varies significantly during different operating conditions of the engine due to centrifugal forces on the rotor and differential thermal expansions in the discs and casing. The tip clearance in the axial flow compressor of modern commercial civil aero-engines is of significance in terms of both mechanical integrity and performance. In general, the clearance is of critical importance to civil airline operators and their customers alike because as the clearance between the compressor blade tips and the casing increases, the aerodynamic efficiency will decrease and therefore the specific fuel consumption and operating costs will increase. This paper reports on the development of a range of concepts and their evaluation for the reduction and control of tip clearance in H.P. compressors using an enhanced heat transfer coefficient approach. This would lead to improvement in cruise tip clearances. A test facility has been developed for the study at the University of Sussex, incorporating a rotor and an inner shaft scaled down from a Rolls-Royce Trent aero-engine to a ratio of 0.7:1 with a rotational speed of up to 10000 rpm. The idle and maximum take-off conditions in the square cycle correspond to in-cavity rotational Reynolds numbers of 3.1×106 ≤ Reφ ≤ 1.0×107. The project involved modelling of the experimental facilities, to demonstrate proof of concept. The analysis shows that increasing the thermal response of the high pressure compressor (HPC) drum of a gas turbine engine assembly will reduce the drum time constant, thereby reducing the re-slam characteristics of the drum causing a reduction in the cold build clearance (CBC), and hence the reduction in cruise clearance. A further reduction can be achieved by introducing radial inflow into the drum cavity to further increase the disc heat transfer coefficient in the cavity; hence a further reduction in disc drum time constant.

ON THE DEVELOPMENT OF TESTING FACILITIES FOR THE SCIENTIFIC TEST-ING CENTER OF THE ROCKET AND SPACE INDUSTRY FOR DEVELOPMENTAL TESTING OF ADVANCED CRYOGENIC PROPULSION SYSTEMS

2021 ◽  
pp. 88-97
Author(s):  
Nikolay P. SIZYAKOV ◽  
Igor A. YURIEV ◽  
Ayvengo G. GALEEV
Keyword(s):  
Propulsion System ◽  
Test Facility ◽  
Launch Vehicles ◽  
Propulsion Systems ◽  
Safety Measures ◽  
Experimental Development ◽  
Space Industry ◽  
Calculation Results ◽  
Testing Center ◽  
Scientific Testing

The paper provides a review of materials on the development of testing facilities in the Scientific Testing Center of the Rocket and Space Industry and the issues involved in raising the efficiency and safety of experimental development of advanced cryogenic propulsion systems for launch vehicles intended for exploration of the near and deep space. It shows that the most dangerous tests are those that are conducted on engines and propulsion systems that use oxygen, methane and hydrogen as propellant components. They may involve containment failure in the propellant system in off-nominal situations — emergency releases of propellant components, explosions and fires. It provides calculation results for overpressure in the shock-wave front depending on the mass of the released hydrogen and the factor of its contribution to the explosion. It formulates special and additional safety measures for engine and propulsion system tests in a test facility. Key words: test facility (test stand), propulsion system, safety, off-nominal situation, cryogenic propellant components.

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