TITLE:
Computational Study on Micro Shock Tube Flows with Gradual Diaphragm Rupture Process
AUTHORS:
Arun Kumar Rajagopal, Heuy Dong Kim, Toshiaki Setoguchi
KEYWORDS:
Diaphragm Rupture; Expansion Wave; Micro Shock Tube; Rarefaction; Unsteady Flow
JOURNAL NAME:
Open Journal of Fluid Dynamics,
Vol.2 No.4A,
December
27,
2012
ABSTRACT: Gas flows through micro shock tubes are widely used in many engineering applications such as micro engines, particle delivery devices etc. Recently, few studies have been carried out to explore the shock wave excursions through micro shock tubes at very low Reynolds number and at rarefied gas condition. But these studies assumed centered shock and expansion waves, which are generally produced by instantaneous diaphragm rupture process. But in real scenario, the diaphragm ruptures with a finite rupture time and this phenomenon will significantly alter the shock wave propagation characteristics. In the present research, numerical simulations have been carried out on a two dimensional micro shock tube model to simulate the effect of finite diaphragm rupture process on the wave characteristics. The rarefaction effect was simulated using Maxwell’s slip wall equations. The results show that shock wave attenuates rapidly in micro shock tubes compared to conventional macro shock tubes. Finite diaphragm rupture causes the formation of non-centered shock wave at some distance ahead of the diaphragm. The shock propagation distance is also drastically reduced by the rupture effects.