Low-Reynolds-Number Effects on Delta-Wing Aerodynamics

摘要

Flow visualization has traditionally provided a powerful technique for both qualitative and quantitative investigations of delta-wing flows. Because low-speed water flows are conducive to flow visualization techniques, many studies have addressed low Reynolds number (Re) flow. Some examples are the investigations of Atta and Rockwell at Re = 5.8 X 10~3, Reynolds and Abtahi at a Re between 1.9 X 10~4 and 6.5 X 10~4, Traub et al. with Re in the neighborhood of 9 X 10~3, and Lowson at Re as low as 6.6 X 10~3 (performed in a wind tunnel). However, accompanying pressure, force, and moment measurements have typically been performed at significantly higher Re because of sensitivity and accuracy limitations of typical pressure and load measurement instrumentation at low dynamic pressures. Most pressure and load measurement efforts have been performed at Re above 0.34 X 10~6. The presence of this Re gap raises the question of flow sensitivity, particularly in the range from 10~4 to 10~5. How reconcilable are the two data sets, i.e., flow visualization data and pressure/ load data? Do they describe the same flow patterns?