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 fluid pressure and
inflow velocity. We present and discuss results for mixed and
forced convection obtained with air as working fluid (Pr �
0.7) at ambient pressure for 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 of Göttingen (HDG) and the
convection cell.
At elevated fluid pressure a significant increase of the
velocity fluctuations was observed. Furthermore for mixed
convection a transition of a stable 2D flow into an instationary
3D flow has been found
