Model reusable rocket stage travels seven times the speed of sound in hypersonic wind tunnel
Model reusable rocket stage travels seven times the speed of sound in hypersonic wind tunnel
This picture shows a reusable rocket stage model re-entering Earth's atmosphere at seven times the speed of sound, in the hypersonic wind tunnel in Cologne (H2K). The engine fires against the direction of travel in order to reduce its speed and in-so-doing minimise the high stresses experienced during re-entry. As part of the ESA RETPRO project, funded by the Future Launchers Preparatory Programme (FLPP), a study was carried out on the influence of firing a varying number of engines on the overall aerodynamics of the rocket stage. The flow is visualised using the schlieren method, in which differences in density lead to the deflection of light guided through the measurement segment. This makes the flow structures clearly visible, especially when it comes to supersonic flows. In the upper image with one engine active, flows are reproduced comparatively sharply, which indicates little dynamic behaviour in the flow field. In the lower image with three active thrusters, the mutual influence of the thruster jets and a clear increase in dynamics can be seen. Such results in the future consideration of how dynamic flow influences the behaviour of the structures and control of spacecraft.
Credit:
DLR, ESA, Future Launchers Preparatory Programme (FLPP)