The development of Doppler global velocimetry is described. Emphasis is placed on the modifications necessary to advance this nonintrusive laser based measurement technique from a laboratory prototype to a viable wind tunnel flow diagnostics tool. Several example wind tunnel flow field investigations are described to illustrate the versatility of the technique. Flow conditions ranged from incom...

In this paper the characteristics of unsteady three-dimensional incompressible flows with heat transfer are obtained along with artificial compressibility of Chorin. At first, compatibility equations and pseudo characteristics for three-dimensional flows are derived from five governing equations (continuity equation, Momentum equations in three directions, and energy equation) and then results ...

Supersonic jets emit noise to the outside in form of Mach waves which are long, straight and have about equal angles. Experiments done by Oertel sen. visualized clearly these Mach waves and he publicized moreover that such Mach waves exist also inside the jet. Experimental and theoretical studies in the past did not allow a complete understanding of the phenomenon up to now, wherefore the need ...

The development of Doppler global velocimetry is described. Emphasis is placed on the modifications necessary to advance this nonintrusive laser based measurement technique from a laboratory prototype to a viable wind tunnel flow diagnostics tool. Several example wind tunnel flow field investigations are described to illustrate the versatility of the technique. Flow conditions ranged from incom...

We have developed a series of benchmark programs to test the performance of the Mach operating system. A discussion of the philosophy of the benchmarks is given, and the individual benchmark programs are described. Results of the benchmarks on 386-based machines running Mach 2.5, Mach 3.0, and SCO System V/386 are given. Appeared in: Proceedings of the USENIX Mach Workshop, 1990, 83-100.

High Mach number astrophysical jets are simulated using a positive scheme, and are compared with WENO-LF simulations. A version of the positive scheme has allowed us to simulate astrophysical jets with radiative cooling up to Mach number 270 with respect to the heavy jet gas, a factor of two times higher than the maximum Mach number attained with the WENO schemes and ten times higher than with ...

Interprocess communication (IPC) provides the fundamental mechanism for the Mach microkernel to be extensible and exible. Mach IPC provides eecient communication mechanisms for many applications. However, it does not provide suucient functionality for real-time applications which have rigid timing constraints among threads. In Real-Time Mach (RT-Mach), we have extended Mach IPC to be priority i...

Mach bands are illusory bright am! da.rk bands seen where a lumin<lnce plateau meets <I ramp, as in half-shadows or penumbras. Ra.tliff, Milkman, and Kaufman (1983) showed that Mach bands are attenmtted by placing stimuli, such as bars, nemby. An experiment comparing Mach band attenuation for bar a.ncl Craik-O'Brien stimuli shows that they are equally effective in attenuating Mach bands. 'J'he ...