New paper on radiation!
The P1 approximation to the radiative transfer equation is coupled to a material response code in order to model ablative materials. These types of materials are used as thermal protection systems for atmospheric entry vehicles. Several test cases are presented to verify the implementation and to validate the approach. Representative conditions -- mimicking an arc-jet, a radiant heating facility, and an atmospheric entry trajectory -- are used to demonstrate the validity of the coupled model. The code is then used to replicate an experiment that studies the effects of the wavelength on the thermal response of charring ablators. Two lasers are used to deliver the heat pulse. The first laser, at a wavelength of 1.07 micron, deposits the energy within the material, as opposed to the 10.6 micron laser, which mostly does it on the surface. The numerical results verify the findings of the experiment, thus confirming the importance of spectrally resolving the radiative heat flux within charring ablators.
Martin, A. and Panesi, M., “Radiative transmission and absorption within the thermal protection system of an atmospheric entry spacecraft,” Journal of Spacecraft and Rockets, 2020.
doi:10.2514/1.A35029