› › Acoustic Flow Related And Performance Related Experimental Results For Generation 1 5 High Speed Civil Transport Hsct 2 Dimensional Exhaust Nozzles

Acoustic, Flow Related, and Performance Related Experimental Results for Generation 1.5 High Speed Civil Transport (Hsct) 2-Dimensional Exhaust Nozzles

Author : National Aeronautics and Space Administration (NASA)

Publisher : Createspace Independent Publishing Platform

Page : 518 pages

File Size : 35,66 MB

Release : 2018-06-27

Category :

ISBN : 9781721982875

Get eBook

Book Description

The principle objectives of the current program were to experimentally investigate the repeatability of acoustic and aerodynamic characteristics of 2D-CD mixer-ejector nozzles and the effects on the acoustic and aerodynamic characteristics of 2D mixer-ejectors due to (1) the configurational variations, which include mixers with aligned CD chutes, aligned convergent chutes, and staggered CD chutes and aerodynamic cycle variables, (2) treatment variations by using different treatment materials, treating the ejector with varying area, location, and treatment thickness for a mixer-ejector configuration, and (3) secondary inlet shape (i.e., a more realistic inlet) and the blockage across the inlet (a possible fin-like structure needed for installation purpose) by modifying one of the inlet of a mixer-ejector configuration. The objectives also included the measurement dynamic pressures internal to the ejector for a few selected configuration to examine the internal noise characteristics. Salikuddin, M. and Wisler, S. and Majjigi, R. Glenn Research Center NAS3-26617; WBS 714-09-46...



Generation 1. 5 High Speed Civil Transport Exhaust Nozzle Program

Author : E. B. Thayer

Publisher : BiblioGov

Page : 196 pages

File Size : 45,22 MB

Release : 2013-07

Category :

ISBN : 9781289261412

Get eBook

Book Description

The objective of this program was to conduct an experimental and analytical evaluation of low noise exhaust nozzles suitable for future High-Speed Civil Transport (HSCT) aircraft. The experimental portion of the program involved parametric subscale performance model tests of mixer/ejector nozzles in the takeoff mode, and high-speed tests of mixer/ejectors converted to two-dimensional convergent-divergent (2-D/C-D), plug, and single expansion ramp nozzles (SERN) in the cruise mode. Mixer/ejector results show measured static thrust coefficients at secondary flow entrainment levels of 70 percent of primary flow. Results of the high-speed performance tests showed that relatively long, straight-wall, C-D nozzles could meet supersonic cruise thrust coefficient goal of 0.982; but the plug, ramp, and shorter C-D nozzles required isentropic contours to reach the same level of performance. The computational fluid dynamic (CFD) study accurately predicted mixer/ejector pressure distributions and shock locations. Heat transfer studies showed that a combination of insulation and convective cooling was more effective than film cooling for nonafterburning, low-noise nozzles. The thrust augmentation study indicated potential benefits for use of ejector nozzles in the subsonic cruise mode if the ejector inlet contains a sonic throat plane.



Generation 1.5 High Speed Civil Transport (Hsct) Exhaust Nozzle Program

Author : National Aeronautics and Space Administration (NASA)

Publisher : Createspace Independent Publishing Platform

Page : 192 pages

File Size : 32,20 MB

Release : 2018-06-15

Category :

ISBN : 9781721142989

Get eBook

Book Description

The objective of this program was to conduct an experimental and analytical evaluation of low noise exhaust nozzles suitable for future High-Speed Civil Transport (HSCT) aircraft. The experimental portion of the program involved parametric subscale performance model tests of mixer/ejector nozzles in the takeoff mode, and high-speed tests of mixer/ejectors converted to two-dimensional convergent-divergent (2-D/C-D), plug, and single expansion ramp nozzles (SERN) in the cruise mode. Mixer/ejector results show measured static thrust coefficients at secondary flow entrainment levels of 70 percent of primary flow. Results of the high-speed performance tests showed that relatively long, straight-wall, C-D nozzles could meet supersonic cruise thrust coefficient goal of 0.982; but the plug, ramp, and shorter C-D nozzles required isentropic contours to reach the same level of performance. The computational fluid dynamic (CFD) study accurately predicted mixer/ejector pressure distributions and shock locations. Heat transfer studies showed that a combination of insulation and convective cooling was more effective than film cooling for nonafterburning, low-noise nozzles. The thrust augmentation study indicated potential benefits for use of ejector nozzles in the subsonic cruise mode if the ejector inlet contains a sonic throat plane. Thayer, E. B. and Gamble, E. J. and Guthrie, A. R. and Kehret, D. F. and Barber, T. J. and Hendricks, G. J. and Nagaraja, K. S. and Minardi, J. E. Glenn Research Center NAS3-26618; WBS 22-714-09-46



Low Noise Exhaust Nozzle Technology Development

Author : R. K. Majjigi

Publisher : BiblioGov

Page : 172 pages

File Size : 32,42 MB

Release : 2013-07

Category :

ISBN : 9781289265908

Get eBook

Book Description

NASA and the U.S. aerospace industry have been assessing the economic viability and environmental acceptability of a second-generation supersonic civil transport, or High Speed Civil Transport (HSCT). Development of a propulsion system that satisfies strict airport noise regulations and provides high levels of cruise and transonic performance with adequate takeoff performance, at an acceptable weight, is critical to the success of any HSCT program. The principal objectives were to: 1. Develop a preliminary design of an innovative 2-D exhaust nozzle with the goal of meeting FAR36 Stage III noise levels and providing high levels of cruise performance with a high specific thrust for Mach 2.4 HSCT with a range of 5000 nmi and a payload of 51,900 lbm, 2. Employ advanced acoustic and aerodynamic codes during preliminary design, 3. Develop a comprehensive acoustic and aerodynamic database through scale-model testing of low-noise, high-performance, 2-D nozzle configurations, based on the preliminary design, and 4. Verify acoustic and aerodynamic predictions by means of scale-model testing. The results were: 1. The preliminary design of a 2-D, convergent/divergent suppressor ejector nozzle for a variable-cycle engine powered, Mach 2.4 HSCT was evolved, 2. Noise goals were predicted to be achievable for three takeoff scenarios, and 3. Impact of noise suppression, nozzle aerodynamic performance, and nozzle weight on HSCT takeoff gross weight were assessed.





Nozzle Aerodynamic Stability During a Throat Shift

Author : National Aeronautics and Space Administration (NASA)

Publisher : Createspace Independent Publishing Platform

Page : 86 pages

File Size : 25,88 MB

Release : 2018-06-03

Category :

ISBN : 9781720648635

Get eBook

Book Description

An experimental investigation was conducted on the internal aerodynamic stability of a family of two-dimensional (2-D) High Speed Civil Transport (HSCT) nozzle concepts. These nozzles function during takeoff as mixer-ejectors to meet acoustic requirements, and then convert to conventional high-performance convergent-divergent (CD) nozzles at cruise. The transition between takeoff mode and cruise mode results in the aerodynamic throat and the minimum cross-sectional area that controls the engine backpressure shifting location within the nozzle. The stability and steadiness of the nozzle aerodynamics during this so called throat shift process can directly affect the engine aerodynamic stability, and the mechanical design of the nozzle. The objective of the study was to determine if pressure spikes or other perturbations occurred during the throat shift process and, if so, identify the caused mechanisms for the perturbations. The two nozzle concepts modeled in the test program were the fixed chute (FC) and downstream mixer (DSM). These 2-D nozzles differ principally in that the FC has a large over-area between the forward throat and aft throat locations, while the DSM has an over-area of only about 10 percent. The conclusions were that engine mass flow and backpressure can be held constant simultaneously during nozzle throat shifts on this class of nozzles, and mode shifts can be accomplished at a constant mass flow and engine backpressure without upstream pressure perturbations.Kawecki, Edwin J. and Ribeiro, Gregg L.Glenn Research CenterAERODYNAMIC STABILITY; NOZZLE GEOMETRY; THROATS; CIVIL AVIATION; SUPERSONIC TRANSPORTS; CONVERGENT-DIVERGENT NOZZLES; TWO DIMENSIONAL FLOW; MIXERS; CHUTES; MASS FLOW; DYNAMIC STABILITY; PERTURBATION







High Speed Nozzles Task

Author : National Aeronautics and Space Administration (NASA)

Publisher : Createspace Independent Publishing Platform

Page : 26 pages

File Size : 23,51 MB

Release : 2018-07-05

Category :

ISBN : 9781722272609

Get eBook

Book Description

Supersonic cruise exhaust nozzles for advanced applications are optimized for a high nozzle pressure ratio (NPR) at design supersonic cruise Mach number and altitude. The performance of these nozzles with large expansion ratios are severely degraded for operations at subsonic speeds near sea level for NPR significantly less than the design values. The prediction of over-expanded 2DCD nozzles performance is critical to evaluating the internal losses and to the optimization of the integrated vehicle and propulsion system performance. The reported research work was aimed at validating and assessing existing computational methods and turbulence models for predicting the flow characteristics and nozzle performance at over-expanded conditions. Flow simulations in 2DCD nozzles were performed using five different turbulence models. The results are compared with the experimental data for the wall pressure distribution and thrust and flow coefficients at over-expanded static conditions. Hamed, Awatef Unspecified Center OAI-120520...