An experimental investigation on effect of ambient flow on aerodynamic performances of an external nozzle

For space plane with air-breathing engines, equipping Single Expansion Ramp Nozzle on its aft-body is beneficial for thrust augmentation. The cowl of this nozzle is truncated (thus, termed as an external nozzle), in order to reduce its weight, friction drag, and cooling requirement, and also to atta...

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Main Authors: Tatsushi ISONO, Sadatake TOMIOKA, Noboru SAKURANAKA
Format: Article
Language:English
Published: The Japan Society of Mechanical Engineers 2016-02-01
Series:Journal of Fluid Science and Technology
Subjects:
Online Access:https://www.jstage.jst.go.jp/article/jfst/11/1/11_2016jfst0002/_pdf/-char/en
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author Tatsushi ISONO
Sadatake TOMIOKA
Noboru SAKURANAKA
author_facet Tatsushi ISONO
Sadatake TOMIOKA
Noboru SAKURANAKA
author_sort Tatsushi ISONO
collection DOAJ
description For space plane with air-breathing engines, equipping Single Expansion Ramp Nozzle on its aft-body is beneficial for thrust augmentation. The cowl of this nozzle is truncated (thus, termed as an external nozzle), in order to reduce its weight, friction drag, and cooling requirement, and also to attain pressure recovery (so-called altitude compensation) on the ramp wall by the impingement of pressure waves generated by the interference between external nozzle flow and ambient flow on ramp wall surface, in case of over-expanded condition. The present study is to evaluate the effects of ambient flow on the external nozzle flow field, as little research has been conducted to elucidate the effects. Room temperature nitrogen gas was injected to simulate air-breathing engine exhaust in cases without and with ambient flow at a supersonic semi-free jet wind tunnel. A straight expansion ramp was employed as the external nozzle. Pressure distributions on the ramp wall were measured and results without and with ambient flow were compared. Comparison showed that presence of ambient flow reduced the magnitude of ramp wall pressure induced by the impingement of pressure waves, and thus, the strength of pressure waves generated by the interference. Flow characterization by pressure wave tracking showed that spatial variation in ambient flow pressure caused this weakening of the incident pressure wave upon the ramp surface. Thus, altitude compensation effect in the over-expanded condition became smaller than that without ambient flow.
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spelling doaj.art-6183d829e0fb4a53bf0e9fbfe1f741902022-12-22T04:13:01ZengThe Japan Society of Mechanical EngineersJournal of Fluid Science and Technology1880-55582016-02-01111JFST0002JFST000210.1299/jfst.2016jfst0002jfstAn experimental investigation on effect of ambient flow on aerodynamic performances of an external nozzleTatsushi ISONO0Sadatake TOMIOKA1Noboru SAKURANAKA2Department of Aerospace Engineering, Tohoku UniversityKakuda Space Center, Japan Aerospace Exploration Agency (JAXA)Kakuda Space Center, Japan Aerospace Exploration Agency (JAXA)For space plane with air-breathing engines, equipping Single Expansion Ramp Nozzle on its aft-body is beneficial for thrust augmentation. The cowl of this nozzle is truncated (thus, termed as an external nozzle), in order to reduce its weight, friction drag, and cooling requirement, and also to attain pressure recovery (so-called altitude compensation) on the ramp wall by the impingement of pressure waves generated by the interference between external nozzle flow and ambient flow on ramp wall surface, in case of over-expanded condition. The present study is to evaluate the effects of ambient flow on the external nozzle flow field, as little research has been conducted to elucidate the effects. Room temperature nitrogen gas was injected to simulate air-breathing engine exhaust in cases without and with ambient flow at a supersonic semi-free jet wind tunnel. A straight expansion ramp was employed as the external nozzle. Pressure distributions on the ramp wall were measured and results without and with ambient flow were compared. Comparison showed that presence of ambient flow reduced the magnitude of ramp wall pressure induced by the impingement of pressure waves, and thus, the strength of pressure waves generated by the interference. Flow characterization by pressure wave tracking showed that spatial variation in ambient flow pressure caused this weakening of the incident pressure wave upon the ramp surface. Thus, altitude compensation effect in the over-expanded condition became smaller than that without ambient flow.https://www.jstage.jst.go.jp/article/jfst/11/1/11_2016jfst0002/_pdf/-char/enwind tunnel testsupersonic flownozzle flowaltitude compensating nozzleambient flow
spellingShingle Tatsushi ISONO
Sadatake TOMIOKA
Noboru SAKURANAKA
An experimental investigation on effect of ambient flow on aerodynamic performances of an external nozzle
Journal of Fluid Science and Technology
wind tunnel test
supersonic flow
nozzle flow
altitude compensating nozzle
ambient flow
title An experimental investigation on effect of ambient flow on aerodynamic performances of an external nozzle
title_full An experimental investigation on effect of ambient flow on aerodynamic performances of an external nozzle
title_fullStr An experimental investigation on effect of ambient flow on aerodynamic performances of an external nozzle
title_full_unstemmed An experimental investigation on effect of ambient flow on aerodynamic performances of an external nozzle
title_short An experimental investigation on effect of ambient flow on aerodynamic performances of an external nozzle
title_sort experimental investigation on effect of ambient flow on aerodynamic performances of an external nozzle
topic wind tunnel test
supersonic flow
nozzle flow
altitude compensating nozzle
ambient flow
url https://www.jstage.jst.go.jp/article/jfst/11/1/11_2016jfst0002/_pdf/-char/en
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