ProjectsThe main objectives of this activity have been the development and validation of models and tools to account for the phenomena linked to the presence of particles in Mars atmosphere. Necessary for this respective test facilities had to be adapted to the specific needs. A large sample test program has been performed – with some surprising results. One focus has been particle erosion and the increase of convective and radiative heat fluxes due to particle effects and associated earlier transition to turbulence. The final goal was to assess and improve the theoretical knowledge, tools and methodologies for the flows with particles, and specifically to provide design rules for heat-shield sizing. One major topic has been the „hot erosion tests“ which have been performed at LDR-Cologne in a wind tunnel with insertion of dust particles.
The limited number of tests performed in the study MDUST for the critical conditions have not provided a substantiated statistical data base which allows properly justified reduction of residual uncertainties and resulting design margins. Therefore investigations on the constitution of the Mars atmosphere and more tests at already known conditions and subsequent test evaluations have been ordered by CNES in the frame of the continuation study “DUST” (2007-2008). Further involved have been CEA (F) and the University of Paris. The test campaign with associated modelling and evaluation activities gave a little bit more understanding of the behaviour of the used ablator material and enabled a more reliable dimensioning prediction for the ablator.
|
|
|
