Direct and large eddy simulations of thermo-convective flows.

Transitional and and turbulent thermo-convective flows in a cylinder heated from below are studied numerically. The governing equations for mass, momentum and energy conservation axe solved in vorticity-stream function-temperature variables utilizing the Boussinesq approximation and a sub-grid-scale turbulence model. The simulations are performed by a finite-difference code employing a combined 2nd and 4th order accurate spatial discretization. The resulting set of equations is factored into one-dimensional operators that are applied in alternating order. Calculations have been run on the CRAY C92 vector processor as well as on the SP2 parallel machine. The results show good performance, especially on the CRAY C92 where up to 550 Mflops were achieved.