Author: Wendell S. Hertzelle
Publisher:
ISBN: 9781423568032
Category :
Languages : en
Pages : 92
Get Book Here
Book Description
Thrust augmenting ejectors were analyzed by the author in an attempt to see if they could be used to provide a significant thrust increase over the baseline thrust of a primary core. This was done for the purpose of determining if leaving the ejectors open in the cruise configuration of the High Speed Civil Transport would lead to a thrust increase that would at least offset the weight of the ejectors themselves. If this was found to be true then the fuel economy of the HSCT might be improved by leaving them open and not closing them during cruise. In analyzing the ejectors, no assumptions were made regarding inlet nor outlet configurations, so an attempt was made to find the point of optimal thrust augmentation by varying secondary stream bypass Mach number and the amount of flow entrainment. Two solutions were found to each mixing scenario, one subsonic and the other supersonic. These two solutions were each analyzed and ones not satisfying the Second Law of Thermodynamics were eliminated. Analytic diffuser and bleed losses were also explored in the analysis of the ejector flow. Within the limitations of the assumptions discussed in this paper, appreciable thrust augmentations have been discovered over a large range of bypass Mach numbers and entrained mass flows. This lead the author to the conclusion that ejectors warrant further research beyond a first order analysis, and serious thought should be put into leaving them open in cruise.
Author: Wendell Scott Hertzelle
Publisher:
ISBN:
Category : Airplanes
Languages : en
Pages : 144
Get Book Here
Book Description
Author:
Publisher:
ISBN:
Category : Airplanes
Languages : en
Pages : 524
Get Book Here
Book Description
Author: Morton Alperin
Publisher:
ISBN:
Category :
Languages : en
Pages : 49
Get Book Here
Book Description
A discussion of the development of the compact jet-diffuser ejectors utilized for hovering and low speed flight propulsion has been presented. This is followed by a description of ideal ejector performance as derived from a compressible flow theory, over the range of flight speeds from zero to supersonic speed. These analyses introduced the concepts of ejector configuration optimization and the validity of the so-called 'second solution' to the mixing problem, wherein the flow after complete mixing is supersonic. The ideal performance of thrust augmenting ejectors designed under this 'second solution' has been shown to be far superior to those designed by conventional methods. The ability of properly designed ejectors to utilize the thermal energy of injected gas for the production of useful energy has also been described. Finally, the influence of major losses has been discussed, including means for avoiding excessive performance degradation by proper optimization of the geometry of the ejector in view of these losses.
Author: B. L. Berrier
Publisher:
ISBN:
Category :
Languages : en
Pages : 88
Get Book Here
Book Description
Author: John E. Minardi
Publisher:
ISBN:
Category : Aerodynamics, Supersonic
Languages : en
Pages : 92
Get Book Here
Book Description
A technique is developed for determining a representative value of the maximum efficiency that can be achieved with high performance ejectors when operating on the supersonic solution branch of an ejector. These efficiencies are used to calculate thrust augmentation for an ejector over a wide range of parameters including operation with a hypothetical engine. Reasonable values of thrust augmentation can be achieved at low subsonic flight mach numbers. However, at flight Mach numbers near one, little or not thrust augmentation was found. At supersonic flight Mach numbers, thrust augmentation was achieved. Basic studies indicated that the effects of temperature was opposite at subsonic and supersonic flight Mach numbers. Thrust augmentation decreased with increasing temperature at subsonic Mach number sand increased with increasing temperature at supersonic Mach numbers.
Author: Bobby L. Berrier
Publisher:
ISBN:
Category : Aerodynamics, Supersonic
Languages : en
Pages : 228
Get Book Here
Book Description
Author: William S. Campbell
Publisher:
ISBN:
Category : Airplanes
Languages : en
Pages : 25
Get Book Here
Book Description
The application of thrust augmentation concepts to short take-off and landing (STOL) aircraft propulsion is described for some typical installations. Aerodynamic and ejector thrust effects are treated separately so that the performance of the ejector-powered wing can be calculated as that of a jet-flapped airfoil and the ejector thrust components then added. Some considerations on the performance of the ejector-powered wing in cruise are included. A program for ejector calculations is given. (Author).
Author: S. G. Reznick
Publisher:
ISBN:
Category :
Languages : en
Pages : 12
Get Book Here
Book Description
Effects of primary jet inlet nozzle configuration and diffuser geometry on the thrust augmentation of circular and rectangular ejectors are investigated in an experimental study. The rectangular ejector inlet nozzle configurations consist of either one, two, or three slot nozzles. The circular ejector inlet nozzles consist of slot nozzles placed either across the inlet or around the inlet periphery. Diffuser geometry is varied primarily by changing the diffuser area ratio. Effect on thrust performance of the primary flow injection angle relative to the inlet walls is investigated. Effects of side-wall, end-wall, and diffuser blowing on thrust performance and diffuser stall also are considered.
Author: R. P. Braden
Publisher:
ISBN:
Category : Short take-off and landing aircraft
Languages : en
Pages : 1094
Get Book Here
Book Description
