Accession Number:

ADA445162

Title:

Wind Tunnel Study of Interference Effects Relating to Aft Supersonic Ejection of a Store

Descriptive Note:

Master's thesis

Corporate Author:

AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH DEPT OF AERONAUTICS AND ASTRONAUTICS

Personal Author(s):

Report Date:

2005-12-01

Pagination or Media Count:

118.0

Abstract:

An investigation into the issues surrounding the release of a store into a supersonic wake was conducted. A 10-degree half-angle cone was used to model the carrier vehicle as well as the store. The store was 42 than the vehicle. The experiments were conducted at a freestream Mach number of 2.93 and at zero degrees angle of attack. This study analyzed the effects of a support or strut mounted under the wind tunnel model. Research was conducted on the effects of a store at various positions in the wake, as well as the effects of a rear cavity in the carrier. Real-time sequences of Schlieren images were used to obtain a visual understanding of these effects. Fast-response pressure transducers and pressure-sensitive paint PSP provided pressure information on the carrier vehicle and store models. Visualizations showed the strut caused the reattachment shock to move closer to the base. Transducers recorded a slight decrease in mean and an increase in standard deviation of pressure behind the strut. From a PSP profile image, the interaction of the oblique shock of the strut with the models conical shock was found to create a vertical pressure gradient. However, base pressure was only modestly affected. The store was manually moved to various axial positions behind the vehicle. The store caused the pressure to rise as the store moved aft. At distance equal to half of the vehicles base diameter, the store had maximum effect, causing an increase in the bases coefficient of pressure. As the store moved father aft, the store had diminishing effects. The cavity was found to have minimal effects on the flowfield. The cavity caused a drop in the vehicles base pressure and the pressure on the store. When the store was inserted into the cavity it excited a characteristic frequency corresponding to a Strouhal number of 0.25, but when the store was removed there were no

Subject Categories:

  • Fluid Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE