Ribbon Surface Pressure and Wake Velocity Data for the Experimental Validation of a Vortex-Based Parachute Inflation Code

MCBRIDE,DONALD DEAN ; CLARK JR,EDWARD LEE ; HENFLING,JOHN F.

Sandia National Laboratories

关键词: Pressure Measurement;    Wind Tunnels;    36 Materials Science;    Stainless Steels;    Boundary Conditions;   

DOI  :  10.2172/783089
RP-ID  :  SAND2001-1631
RP-ID  :  AC04-94AL85000
RP-ID  :  783089

美国|英语

来源: UNT Digital Library

【 摘 要 】

An experiment to measure surface pressure data on a series of three stainless steel simulated parachute ribbons was conducted. During the first phase of the test, unsteady pressure measurements were made on the windward and leeward sides of the ribbons to determine the statistical properties of the surface pressures. Particle Image Velocimetry (PIV) measurements were simultaneously made to establish the velocity field in the wake of the ribbons and its correlation with the pressure measurements. In the second phase of the test, steady-state pressure measurements were made to establish the pressure distributions. In the third phase, the stainless steel ribbons were replaced with nylon ribbons and PIV measurements were made in the wake. A detailed error analysis indicates that the accuracy of the pressure measurements was very good. However, an anomaly in the flow field caused the wake behind the stainless steel ribbons to establish itself in a stable manner on one side of the model. This same stability was not present for the nylon ribbon model although an average of the wake velocity data indicated an apparent 2{degree} upwash in the wind tunnel flow field. Since flow angularity upstream of the model was not measured, the use of the data for code validation is not recommended without a second experiment to establish that upstream boundary condition.