Studies on the starting transient of a straight cylindrical supersonic exhaust diffuser: Effects of diffuser length and pre-evacuation state

被引：23

作者：

Park, Byung Hoon ^{[1
]}

Lee, Ji Hyung ^{[1
]}

Yoon, Woongsup ^{[1
]}

机构：

[1] Yonsei Univ, Prop & Environm Thermofluids Lab, Sch Mech Engn, Seoul 120749, South Korea

来源：

INTERNATIONAL JOURNAL OF HEAT AND FLUID FLOW | 2008年 / 29卷 / 05期

关键词：

Supersonic exhaust diffuser (SED); High altitude test (HAT); Starting transient; Short diffuser; Diffuser mode-transition;

D O I：

10.1016/j.ijheatfluidflow.2008.04.006

中图分类号：

O414.1 [热力学];

学科分类号：

摘要：

Effects of essential performance parameters on the starting transient of a straight cylindrical supersonic exhaust diffuser (SED) are numerically investigated. Diffuser starting and evacuation transients are examined in terms of SED lengths and pre-evacuation configuration. Preconditioned Favre-averaged Navier-Stokes equations incorporated with a low Reynolds number turbulence model and Sakar's method to treat turbulence compressibility is solved for strongly turbulent all-Mach diffuser flows. The numerical method is properly validated with the measurements with accuracy. Characteristic locus of diffuser-starting and diffuser-unstarting modes is constructed for the diffusers of three different lengths (L/D = 2, 5, and 20). Flow evolutions visualized in diffuser mode-transition regimes manifest a threshold L/D over which the SED starting transient is unique. An occurrence of plume blowback into the vacuum chamber due to lower initial pressure (P-C.INIT/P-A = 0.0027) expedites expansion of nozzle exhaust and diffuser choking, and causes faster chamber evacuation than the atmospheric starting. (C) 2008 Elsevier Inc. All rights reserved.

引用

页码：1369 / 1379

页数：11