23rd AIAA Aerodynamic Decelerator Systems Technology Conference, March 30 - April 2, 2015, Daytona Beach, FL, USA
The pressure-sensitive paint technique (PSP) is used to measure the model surface pressures in wind tunnel testing. Generally, the models are rigid and their motion/deformation under the effect of the flowfield is small and easily corrected. The present study addresses the problem of surface pressure measurements on flexible parachute models as part of the European Space Agency MREP programme activity designed to identify parachutes for future missions. The paper explores the application of the lifetime method using double shutter cameras, the PCO.1600 (PCO) and Zyla (Andor), with a commercial PSP formulation (Unifib from ISSI) tested on solid samples. The effects of the acquisition settings on the noise level is analyzed. In addition, the effect of the paints and primers on the stiffness of polyester parachutes is presented. An original PSP formulation, combining a fluorinated polymer and a silicone rubber was developed to minimize the impact on the fabric stiffness. The noise levels on a single acquisition (no averaging) were too large for a low-speed wind tunnel testing and strategies to reduce the noise levels are proposed in the paper.
American Institute of Aeronautics and Astronautics