Scaling of turbulent mixed convection under high pressure

Abstract

Measurement of turbulent mixed convection at reduced model size by aerodynamic scaling is a promising approach to simplify the investigation of many technical configurations and offers the potential to make large scale flows accessible on a laboratory scale. First results of an experimental study of turbulent mixed convection in a generic convection cell at ambient and high pressure are reported. The aim of these measurements is to prove the possibility of scaling mixed convection by varying pressure and inflow velocity. We present and discuss results for mixed and forced convection obtained with air as working fluid at ambient pressure with Gr = 3.52*10⁶, Re = 1.1*10³ and thus Ar = 1.81 and at 10 bar with Gr = 3.51*10⁸, Re = 1.1*10⁴ and thus Ar = 1.83. The scaling theory, which allows to scale the cell, is presented as well as the PIV set up used for measurement at high pressure conditions in the high pressure wind tunnel in Göttingen (HDG) and the cell.