LDV Investigation Of Support Structure Influence On The Flow Field Near TheWingtip Of a STOVL Configuration In Hover

摘要

Acquisition phase zero (Concept Exploration) of the Advanced Short Takeoff/Vertical Land (ASTOYL) aircraft development includes, among other tests, evaluation of forces and moments on a large-scale powered model (LSPM) suspended in the Outdoor Aerodynamic Research Facility (OARF) at the NASA Ames Research Center. This investigation assessed the influence of the OARF support structure upon the flow field through LDV measurements in the vicinity of the struts and the wingtip of a generic flat-plate model mounted in the sub-scale NPS ground effects test rig. The model was a twin subcritical jet configuration with the nozzles arranged in tandem. The test environment was saturation seeded using a smoke generator and LDV measurements were made in the entrained flow. Non-coincident measurements were made to determine the three component mean velocities at points in the region of interest and the component mean and composite mean velocities compared for configurations with struts present and struts removed. Variations were discernible in the component mean velocities between samples both in the same strut configuration and between the struts-installed and struts-removed configurations, but were generally small enough to be considered negligible.