A modeling and experimental study was performed to examine the jet attachment process, which can develop during the fluidic thrust vector control of subsonic and supersonic jets. Experiments performed in rectangular jets up to Mach 1.4 revealed that continuous control of jet exhaust is possible with secondary mass flow rates of the order of 1% of the primary jet mass. Under certain operating co...

In this study, the supersonic and choked subsonic flows through micro/nano channels are investigated using direct simulation Monte Carlo (DSMC) method. The supersonic case is simulated at different Knudsen numbers covering slip to transition flow regimes, while the effects of inlet Mach and back pressure are studied in details. The inlet/outlet pressure boundary conditions are suitably implemen...

We consider gas flow in pipe networks governed by the isothermal Euler equations. A set of coupling conditions are required to completely specify the Riemann problem at the junction. The momentum related condition has no obvious expression and different approaches have been used in previous work. For the condition of equal momentum flux, Colombo and Garavello [Netw. Heterog. Media, 1 (2006), pp...

We have modelled ultracompact H ii regions (UCHiiR) in terms of steady subsonic ionized flows in a clumpy medium. Mass loss from neutral clumps allows the regions to be long-lived. We examine the form of global flows for different dependences of the volume mass injection rate, ˙ q, on radius and Mach number, and describe the solutions in detail. We find that three observed UCHiiR morphologies a...

We study the characteristics of the outflow in disks of Be stars, based on the viscous decretion disk scenario. In this scenario, the matter ejected from the equatorial surface of the star drifts outward because of the effect of viscosity, and forms the disk. For simplicity, we adopt the α-prescription for the viscous stress, and assume the disk to be isothermal. Solving the resulting wind equa...

We show the multidimensional stability of subsonic phase transitions in a non-isothermal van der Waals fluid. Based on the existence result of planar waves in our previous work [1], a jump condition is posed on non-isothermal phase boundaries which makes the argument possible. Stability of planar waves both in one dimensional and multidimensional spaces are proved.

An efficient overlapping-mesh method for Euler flow solvers is developed and applied to two-body flow field problems. It features simple procedures to determine the interface cells on which the flow quantities are to be transferred from one mesh system to the other. This allows a great flexibility of mesh arrangements. The method is applied to two cases; one is the transonic flow field around v...