Andrea Lani

A Residual Distribution Method for Symmetrized Systems in Thermochemical Nonequilibrium

A computational model based on a Residual Distribution method for unstructured meshes applied to symmetrizable systems in thermo-chemical nonequilibrium is discussed. At

Assessment and Validation of the Rebuilding process of Test conditions in VKI-Longshot Hypersonic facility

In order to investigate the accuracy of the rebuilding code for the free stream conditions and the total enthalpy in the VKI-Longshot facility, a series of unsteady numerical computations of axisymmetric hypersonic ow over a heat ux probe have been performed. The free stream and the total conditions provided by experiments as function of time were used as unsteady inlet boundary conditions for these simulations. The full 20 ms of the test are simulated by means of unsteady second order time accurate nite volume solver. Numerical methods and the time integration procedure used during this investigation are described. Good agreement is obtained between the numerical results and the measured data for both the stagnation pressure and the heat ux during the useful test time. The limitation of the current rebuilding procedure is discussed and a new method based on coupling CFD and experimental data is developed.

Assessment of Residual Distribution Method Heat Flux Prediction Capabilities: Application to Atmospheric Entry Problems

In the present contribution we evaluate the heat flux prediction capabilities of secondorder accurate Residual Distribution methods in the context of atmospheric entry problems around blunt bodies. Our departing point is the computation of subsonic air flows (with air modeled either as an inert ideal gas or as chemically reacting and possibly out of thermal equilibrium gas mixture) around probe-like geometries, as those typically employed into high enthalpy wind tunnels. We confirm the agreement between the solutions obtained with the Residual Distribution method and the solutions computed with other Finite Volume based codes. Straightforward application of the same technique for hypersonic cases involving strong shocks exhibit severe deficiencies. We investigate new variants of residual distribution schemes in an attempt to mitigate this problem.

Numerical Investigations of Local Correlation-Based Transition Model in Hypersonic Flows

Numerical simulations of hypersonic ows using local correlation based transition (LCTM) model was performed in order to assess the accuracy of the model in hypersonic conditions. Implementation of the model was done in object oriented framework. The governing equations as well as the numerical methods are described. A series of runs were performed for simulating Mach 8 ow over a 7 half angle sharp cone, using three di erent free stream turbulence intensity levels. Moreover, both Laminar and fully turbulent cases were also considered. The LCTM model behaves pretty well and the heat ux remain bounded between laminar and fully turbulent case. The model shows strong sensitivity to the free stream turbulence intensity level regarding the transition location. The results were compared with Kimmel ’s experimental data and good agreement was obtained with 1% free stream turbulence intensity level.