Measurements of convective heat transfer are carried out in separated and reattached cavity flow regions of a two-dimensional incompressible turbulent air flow past two vertical fences on the flat plate affected by upstream velocity and width between two fences.
Under the conditions of flow tested, the flow separation occured at a distance of about two times the fence height upstream from the front face of the first fence and the flow reattachment occured at a distance of about thirteen times the fence height downstream from the first fence in the closed type cavity flow.
However, compared with the flow past a single fence on the flat plate, the reattachment distance downstream from the second fence is shorter.
Detailed distributions of static pressure, velocity and wall temparature are measured in the separation and reattachment regions as well as re-separation and re-attachment regions.
It is found that the local heat transfer coefficient becomes maximum at the reattachment point and minimum around the corner of the rear face of the first fence.
The mean heat transfer coefficient between two fences is given by a power law relationship with the upstream velocity, i.e. $h\propto U^n$ where n=0.34∼0.37.
