DLR AS HYP Transition Experiments on BOLT Modell in H2K
Abstract
The correct prediction of the laminar to turbulent boundary layer transition is essential for the development of hypersonic vehicles. Most of the available ground and flight tests data are gained with conical or other convex geometries. The aim of the Boundary Layer Transition (BOLT) Flight Test Program is the investigation of the transition process on a more complex geometry with concave surfaces. It is expected, that cross flow instabilities influence the transition process significantly. In addition the effect of surface roughness is tested on the identical upper and lower surface. The suggested experiments include investigations of the BOLT geometry in the hypersonic test section (H2K) of the German Aerospace Center (DLR) in Cologne. Experiments will be performed at different Reynolds numbers, different angles of attack and combinations of angle of attack and yaw angle. The transition mechanism will be investigated based on the heat flux with high spatial resolution and as well as the PCB data with high temporal resolution. To determine differences of the transition process on convex and concave surfaces, the availability of experimental data of cone models from the same facility and measuring equipment is advantageous. In addition the H2K data can be compared to the potential flight test data as well as to the results of other ground test facilities and numerical simulations. This comparison should give insight to what extent quiet flow, high enthalpies and long duration are mandatory for the correct prediction of the transition process and position.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jan 14, 2022
- Source ID
- FA95501917028
Entities
People
- Thomas Thiele
Organizations
- Air Force Office of Scientific Research
- German Aerospace Center
- United States Air Force