An experimental investigation was conducted to determine cavity flow-characteristics at subsonic and transonic speeds. A rectangular box cavity was tested in the Langley 8-Foot Transonic Pressure Tunnel at Mach numbers from 0.20 to 0.95 at a unit Reynolds number of approximately 3 x 10(exp 6) per foot. The boundary layer approaching the cavity was turbulent. Cavities were tested over a range of length-to-depth ratios (l/h) of 1 to 17.5 for cavity width-to-depth ratios of 1, 4, 8, and 16. Fluctuating- and static-pressure data in the cavity were obtained; however, only static-pressure data is analyzed. The boundaries between the flow regimes based on cavity length-to-depth ratio were determined. The change to transitional flow from open flow occurs at l/h at approximately 6-8 however, the change from transitional- to closed-cavity flow occurred over a wide range of l/h and was dependent on Mach number and cavity configuration. The change from closed to open flow as found to occur gradually. The effect of changing cavity dimensions showed that if the vlaue of l/h was kept fixed but the cavity width was decreased or cavity height was increased, the cavity pressure distribution tended more toward a more closed flow distribution. Plentovich, E. B. and Stallings, Robert L., Jr. and Tracy, M. B. Langley Research Center...

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For the fourth time, the Leibniz Supercomputing Centre (LRZ) and the Com- tence Network for Technical, Scienti c High Performance Computing in Bavaria (KONWIHR) publishes the results from scienti c projects conducted on the c- puter systems HLRB I and II (High Performance Computer in Bavaria). This book reports the research carried out on the HLRB systems within the last three years and compiles the proceedings of the Third Joint HLRB and KONWIHR Result and Reviewing Workshop (3rd and 4th December 2007) in Garching. In 2000, HLRB I was the rst system in Europe that was capable of performing more than one Tera op/s or one billion oating point operations per second. In 2006 it was replaced by HLRB II. After a substantial upgrade it now achieves a peak performance of more than 62 Tera op/s. To install and operate this powerful system, LRZ had to move to its new facilities in Garching. However, the situation regarding the need for more computation cycles has not changed much since 2000. The demand for higher performance is still present, a trend that is likely to continue for the foreseeable future. Other resources like memory and disk space are currently in suf cient abundance on this new system.