Friedolin T. Strauss, Stephan General, Patrick A. Cragg, Stefan Schlechtriem

DOI Number XXX-YYY-ZZZ

Conference Number HiSST-2022-7

This publication presents the results of an ongoing investigation into transpiration cooling of scramjets
at the German Aerospace Center (DLR). It summarizes the shock-boundary layer interaction results and
the influence of this interaction on the systems’ cooling efficiency and performance from more than
1000 hot run tests. Special focus is placed on the local static pressure distribution on the upper wall in
the coolant wake region. Furthermore, different flow interaction phenomena were discovered and are
thoroughly analyzed by the application of state of the art optical and non-intrusive measurement
techniques like Background Oriented Schlieren (BOS) combined with pressure and temperature data
analysis and correlations. The unique SBLI behavior of the coolant is addressed in this publication.
Three different porous wall materials made of sintered stainless steel are compared and analyzed in
terms of performance and sensitivity to shock-boundary layer interaction issues. It was found that the
shock generator generates a stronger geometric contraction in the hot gas main flow if positioned at
the downstream position. Thus, this position is more prone t generating shock trains and generates a
stronger impact on the static wall pressure distribution in the coolant wake region. It is proven in this
publication that the main drivers for influencing the static wall pressure distribution are the hot gas
mass flow rate (stagnation pressure more important than stagnation temperature) and the
impingement position of the shock generator’s oblique shock. The static wall pressure distribution was
found to be mostly independent of the changes in static wall temperature and in cooling efficiency. An
outlook on the results of additional experiments using different types of porous media (e.g. ceramics)
and improved measurement techniques with the same coolants is also presented. Further research
requirements and subsequent changes in the test setup are discussed

Read the full paper >

In Categories: 1.Events, HiSST 2022, Testing and Evaluation
Email
Print
LinkedIn
The paper above was part of  proceedings of a CEAS event and as such the author has signed a publication agreement to have their paper published in the repository. In the case this paper is found somewhere else CEAS always links to the other source.  CEAS takes great care in making the correct content available to the reader. If any mistakes are found  in the listings please contact us directly at papers@aerospacerepository.org and we will correct the listing promptly.  CEAS cannot be held liable either for mistakes in editorial or technical aspects, nor for omissions, nor for the correctness of the content. In particular, CEAS does not guarantee completeness or correctness of information contained in external websites which can be accessed via links from CEAS’s websites. Despite accurate research on the content of such linked external websites, CEAS cannot be held liable for their content. Only the content providers of such external sites are liable for their content. Should you notice any mistake in technical or editorial aspects of the CEAS site, please do not hesitate to inform us.