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Cold-gas experiments to study the flow separation characteristics of a dual-bell nozzle during its transition modes

Verma, S.B. and Stark, Ralf and Nürnberger-Génin, C. and Haidn, O. (2010) Cold-gas experiments to study the flow separation characteristics of a dual-bell nozzle during its transition modes. Shock Waves, Vol. 2 (no. 3). Springer. DOI: 10.1007/s00193-010-0259-x ISSN 0938-1287

Full text not available from this repository.

Abstract

An experimental investigation has been carried out to study the effect of test environment on transition characteristics and the flow unsteadiness associated with the transition modes of a dual-bell nozzle. Cold-gas tests using gaseous nitrogen were carried out in (i) a horizontal test-rig with nozzle exhausting into atmospheric conditions and, (ii) a high altitude simulation chamber with nozzle operation under self-evacuation mode. Transient tests indicate that increasing δP 0/δt (the rate of stagnation chamber pressure change) reduces the amplitude of pressure fluctuations of the separation shock at the wall inflection point. This is preferable from the viewpoint of lowering the possible risk of any structural failure during the transition mode. Sea-level tests show 15–17% decrease in the transition nozzle pressure ratio (NPR) during subsequent tests in a single run primarily due to frost formation in the nozzle extension up to the wall inflection location. Frost reduces the wall inflection angle and hence, the transition NPR. However, tests inside the altitude chamber show nearly constant NPR value during subsequent runs primarily due to decrease in back temperature with decrease in back pressure that prevents any frost formation.

Item URL in elib:https://elib.dlr.de/67442/
Document Type:Article
Title:Cold-gas experiments to study the flow separation characteristics of a dual-bell nozzle during its transition modes
Authors:
AuthorsInstitution or Email of AuthorsAuthors ORCID iD
Verma, S.B.NAL Bangalore, IndiaUNSPECIFIED
Stark, RalfRalf.Stark (at) dlr.dehttps://orcid.org/0000-0003-1923-1901
Nürnberger-Génin, C.Chloe.Genin (at) dlr.deUNSPECIFIED
Haidn, O.DLR LampoldshausenUNSPECIFIED
Date:2010
Journal or Publication Title:Shock Waves
Refereed publication:Yes
Open Access:No
Gold Open Access:No
In SCOPUS:Yes
In ISI Web of Science:Yes
Volume:Vol. 2
DOI :10.1007/s00193-010-0259-x
Publisher:Springer
ISSN:0938-1287
Status:Published
Keywords:Dual-bell nozzle - Transition modes - Shock unsteadiness - Frost formation - Side-loads
HGF - Research field:Aeronautics, Space and Transport (old)
HGF - Program:Space (old)
HGF - Program Themes:W - no assignment
DLR - Research area:Space
DLR - Program:W - no assignment
DLR - Research theme (Project):W - no assignment (old)
Location: Lampoldshausen
Institutes and Institutions:Institute of Space Propulsion > Technologie
Deposited By: Hanke, Michaela
Deposited On:15 Dec 2010 07:54
Last Modified:10 Jan 2019 15:50

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