Aerothermodynamic Simulations of the Huygens Probe During the Hasi Balloon Flight Campaign

An explicit algebraic Reynolds stress model has been developed in order to investigate the turbulent flow around the Huygens probe during its descent phase in earth atmosphere. The developing of the turbulence model has been focused on the achievement of good numerical predictions of the aerodynamic forces, the spin velocity profile, and the convective heat flux trough the probe. The variable turbulent viscosity coefficient has been obtained using a simplified algebraic equation of the second order invariant of the Reynolds stress anisotropy tensor that accounts for the variations of the production to dissipation ratio. The numerical simulations has been performed with a finite element commercial code in which the turbulence model subroutines have been implemented. The results of the numerical simulations have shown that the predictions given by the present model are in good agreement with the data supplied by the experimental campaign of the 2003 HASI balloon flight.