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Journal ArticleDOI

Evaluation of the performance of supersonic exhaust diffuser using scaled down models

TL;DR: In this article, a straight cylindrical supersonic exhaust diffusers (SED) using cold nitrogen and hot rocket exhaust gases as driving fluids were used to evaluate the effects of the ratios of the SED area to rocket nozzle throat area (Ad/At), SED areas to rocket exhaust manifold exit area, SED length to its diameter (L/D), and specific heat ratio of the driving gases (k) on the minimum starting pressure ratio, (Po/Pa)st, of SED.
About: This article is published in Experimental Thermal and Fluid Science.The article was published on 1998-07-01. It has received 64 citations till now. The article focuses on the topics: Rocket engine nozzle & Rocket.
Citations
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Journal ArticleDOI
TL;DR: In this article, the starting transient and plume blowback at diffuser breakdown of a straight cylindrical supersonic exhaust diffuser with no externally supplied secondary flow are numerically investigated.

36 citations

Journal ArticleDOI
TL;DR: In this article, the authors deal with the high-altitude simulation and testing of upper stage rocket motors with large nozzle area ratios, using second-throat exhaust diffusers (STED).
Abstract: This paper deals with the high-altitude simulation and testing of upper stage rocket motors with large-nozzle area ratios, using second-throat exhaust diffusers (STED). To evaluate the performance ...

32 citations

Journal ArticleDOI
15 Oct 2018-Energy
TL;DR: In this article, a low area ratio rectangular supersonic gaseous ejector is subjected to parametric evaluation to calculate the performance parameters like stagnation pressure ratio, compression ratio, entrainment ratio and the mixing parameter known as non-mixed length.

28 citations

Journal ArticleDOI
TL;DR: In this paper, the design and operational parameters of rocket exhaust diffusers equipped to simulate high-altitude rocket performance on the ground were investigated and characterized using a comprehensive approach (theoretical, numerical, and experimental).
Abstract: The design and operational parameters of rocket exhaust diffusers equipped to simulate high-altitude rocket performance on the ground were investigated and characterized using a comprehensive approach (theoretical, numerical, and experimental). The physical model of concern includes a rocket motor, a vacuum chamber, and a diffuser, which have axisymmetric configurations. Further, the operational characteristics of a rocket exhaust diffuserwereanalyzed froma flowdevelopmentpointof view.Emphasiswasplacedondetailed flowstructure inthe diffuser, to observe the pressure oscillation in both the vacuum chamber and diffuser, which determines the minimum rocket-motor pressure required to start the diffuser. Numerical simulations were compared with experimental data on startup and in operational conditions to understand the effects of major design parameters, including the area ratio of diffuser to rocket-motor nozzle throat, the rocket-motor pressure, and the vacuumchamber size. Nomenclature Ad = inner cross-sectional area of diffuser Ade = exit cross-sectional area of diffuser Ae = exit cross-sectional area of rocket nozzle At = throat cross-sectional area of rocket nozzle

27 citations


Cites background from "Evaluation of the performance of su..."

  • ...Studies on testing methods, design methods, and the internal flow of diffuser systems simulating high-altitude conditions have been performed in research institutes, industries, and academic laboratories since the mid-1950s [5–12]....

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Journal ArticleDOI
TL;DR: In this paper, an experimental investigation was conducted to study the Reynolds number influence on dual-bell transition behavior for tests inside a high-altitude simulation chamber, where the authors found that the width of the inflection region decreases with an increase in the nozzle Reynolds number.
Abstract: An experimental investigation was conducted to study the Reynolds number influence on dual-bell transition behavior for tests inside a high-altitude simulation chamber. For the range of nozzle supply pressures tested, the nozzle Reynolds number is seen to gradually decrease from a relatively high value (of the order of 107 for tests in sea-level atmospheric conditions) toward the transitional range (lower side of 106 for tests inside the high-altitude chamber). This influences the width of the inflection region, which is seen to decrease with an increase in nozzle Reynolds number. Because of the smaller negative pressure gradient experienced during sneak transition with a decrease in nozzle Reynolds number, the separation point is seen to move into the region of wall inflection much earlier and tends to stay in the region of wall inflection for a relatively longer time. Although the time duration of final transition remains more or less constant for different nozzle supply pressure values, the time durati...

24 citations


Cites methods from "Evaluation of the performance of su..."

  • ...Such a high-altitude test facility primarily includes an ejector nozzle to evacuate the altitude chamber, either singly or in combination with other simulation methods [23–27] and provides a platform for conducting subscale cold gas tests on topics of basic and cost-effective research....

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References
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Journal ArticleDOI
TL;DR: The material presented in this paper covers the method of describing the uncertainties in an engineering experiment and the necessary background material, as well as a technique for numerically executing uncertainty analyses when computerized data interpretation is involved.

6,868 citations

Book
01 Jan 1953
TL;DR: In this paper, the Hodograph Method for Two-Dimensional, Subsonic Flow with Small Perturbations is used to describe the dynamics of two-dimensional and three-dimensional flow.
Abstract: Partial table of contents: BACKGROUND. Foundations of Fluid Dynamics. Foundations of Thermodynamics. ONE--DIMENSIONAL FLOW. Isentropic Flow. Normal Shock Waves. Flow in Ducts with Heating or Cooling. INTRODUCTION TO FLOW IN TWO AND THREE DIMENSIONS. The Equations of Motion for Steady, Irrotational Flow. SUBSONIC FLOW. Hodograph Method for Two--Dimensional, Subsonic Flow. Three--Dimensional, Subsonic Flow. SUPERSONIC FLOW. Two--Dimensional, Supersonic Flow with Small Perturbations. Oblique Shocks. Appendices. Index.

2,243 citations

Book
01 Oct 1985
TL;DR: In this article, the dynamique des : gaz, ecoulement : compressible, chocs, systemes a : reaction reference record created on 2005-11-18, modified on 2016-08-08
Abstract: Keywords: dynamique des : gaz ; ecoulement : compressible ; chocs ; systemes a : reaction Reference Record created on 2005-11-18, modified on 2016-08-08

280 citations

Journal ArticleDOI
TL;DR: In this article, wall static and in-stream phot pressure distributions are presented for confined, nonreacting, supersonic flows in cylindrical sections wherein a shock structure has been stabilized.
Abstract: Wall static and in-stream phot pressure distributions are presented for confined, nonreacting, supersonic flows in cylindrical sections wherein a shock structure has been stabilized. Based on an analysis of these measurements, the character of the wave structure is shown to be oblique rather than normal, with the flow remaining primarily supersonic downstream of the shock system. When additional cylindrical sections are either added or deleted the shock structure is, with the exception of slight changes due to the different initial conditions, independent of location in the duct. The parameters which govern the distance st, over which the pressure rise is spread, viz., Mach number, momentum thickness Reynolds number, duct diameter, and the momentum thickness of the upstream boundary layer, were varied as follows: 1.53 ^ Ma ^ 2.72, 5 x 10 ^ Ree ^ 6 x 10, 1.0 D 6.1 in., and 0.007 ^ 6 ^ 0.036 in. In each test the wave structure was generated by either lowering the pressure in the air supply system so that the cylindrical duct was, in effect, overexpanded when discharging to ambient conditions, or by throttling the flow leaving the duct. For a given pressure ratio across the disturbance, Pf/pa, st varies approximately directly with the product 0D and inversely with (Ma — l)Re0. A simple quadratic expression is presented which adequately represents this corespondence for the complete range of conditions tested and for data from the cited reference.

280 citations