Shock Wave / Boundary Layer Interaction Experiment on Control Surface

The shock wave / boundary layer interaction (SWBLI) experiment is part of the EXPERT mission. SWBLI is studied on two identical fixed compression ramps made of C/SiC, which are models for control surfaces. The flow separates on the flat surfaces upstream of the compression ramps and reattaches on the ramp surfaces. A reattachment shock results, which interacts with the boundary layer. One ramp is instrumented with thermocouples. An infrared camera (InGaAs detector array) views the inside of the second flap. A 50 nm bandpass in front of the detector extends its temperature measurement range to over 2,000 K. This provides temperature maps with a spatial resolution of O(1 mm) at 30 Hz. The heat flux on the flap’s exterior is obtained from the temperature distribution history and the known thermal properties of the structure using an inverse method. The locations of the detachment and reattachment shocks are very sensitive to numerical errors and changes of the flow conditions. This flow phenomenon is thus highly suitable to validate numerical results and to examine if and how wind tunnel results can be extrapolated to re-entry flows. The status quo of the payload design is described; CFD and FEM results are presented. 1.0 INTRODUCTION The challenges in designing in-flight space of re-entry experiments are different from those for groundbased experiments. While the ultimate objective – to obtain data with the highest possible accuracy – is the same, the constraints posed by the vehicle size, mass, mechanical loads, thermal loads, power, data storage and experiment control, to name just a few, typically mean that techniques, which are considered standard in a laboratory setting are state-of-the-art for flight experiments. Also, a new measurement technique goes along with new hardware, which has to be customized and qualified for space applications. This is a lengthy (and risky) process and is partly to blame for the lag between when a technique could be applied to in-flight tests (i.e., when all necessary components are available to meet the requirements and constraints mentioned above) and when it is actually applied. Another contributor is the lack of launch Figure 1: EXPERT vehicle with four ramps. Color-coding reflects numerical results of the surface heat flux. RTO-EN-AVT-130 14 1 Schlamp, S.; Prochazka, L.; Rösgen, T. (2007) Shock Wave / Boundary Layer Interaction Experiment on Control Surface. In Flight Experiments for Hypersonic Vehicle Development (pp. 14-1 – 14-22). Educational Notes RTO-EN-AVT-130, Paper 14. Neuilly-sur-Seine, France: RTO. Available from: http://www.rto.nato.int/abstracts.asp. Report Documentation Page Form Approved OMB No. 0704-0188 Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to a penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. 1. REPORT DATE 01 JUN 2007 2. REPORT TYPE N/A 3. DATES COVERED 4. TITLE AND SUBTITLE Shock Wave/Boundary Layer Interaction Experiment on Control Surface 5a. CONTRACT NUMBER