Investigations on Minichannel Gas Cooling
Profiles of the axial velocity component have been measured by Laser-Doppler-Anemometry (LDA) with a resolution of 40µm inside a flat minichannel of 1mm channel height. Time averaged velocity as well as higher statistical moments have been calculated and analysed, as well as compared to CFD calculations testing various turbulence models. In the inlet section up to 60mm downstream of the inlet nozzle, the flow showed characteristically transitional profiles for mean velocity, turbulence intensity and skewness. These investigations stressed the high importance of controlling the inlet turbulence conditions of the HFTM cooling channels.
Left: LDA setup for measurement inside a 1mm minichannel, Right: Results for measured velocity profiles (50mm downsream of nozzle) transformed to wall coordinates and compared to the laminar and universal turbulent velocity profiles