In space missions, the atmospheric entries present a critical challenge for the design of spacecraft due to the extreme external environment that they must endure. Thermal protection systems (TPSs) are required to prevent any damage to the spacecraft, its internal components or passengers. A very common and highly reliable TPS type is based on the use of ablative materials. The improvement of the ablator simulation procedure in its entirety, from the fist phases of the design process to the exceptionally accurate modelling of the material behaviour in the final stages, is the focus of the study herein presented. In order to achieve this goal, two activities were completed: the creation of a new simulation tool and the precise characterization of porous material permeability. The simulation tool consists of a novel and low computationally demanding coupled methodology able to simulate the three-dimensional behaviour of ablative TPSs. This tool is composed by the Ablative Response Code (ARC), which was specifically designed for this task, and reduced order aero-thermodynamic models. The property characterization was performed using the DSMC (Direct Simulation Monte Carlo) method. This activity evaluated the changes in permeability, commonly considered constant, caused by the variations in temperature and pressure occurring during a (re-)entry. The combination of the activities generated for this dissertation can be used for both the design of future mission TPSs and the development of next generation ablative materials. Simulation results produced for several test cases with different planets' atmospheres and examples of possible applications are presented as confirmation of the developed methods relevance for ablative design and development.
|Date of Award||17 Sep 2018|
- University Of Strathclyde
|Sponsors||University of Strathclyde|
|Supervisor||William Dempster (Supervisor) & Marcello Lappa (Supervisor)|