Abstract: IFA300 isothermal HWFA is used to measure and study the turbulent flow in hot air channels of a heat exchanger. The experimental results obtained by using one-dimensional probes show that the heat transfer boundary conditions have a small effect on the distribution of non-dimensional mean velocity in the measuring field, whereas different heat transfer boundary conditions have a certain effect on the distribution of turbulent intensity. Combined with the experimental results obtained by using two-dimensional probes, it is illustrated that when the boundary is cooled, the main reason why the turbulent fluctuation is aggravated lies in the volume variation of the air near the wall.

Key words: Cooling, Heat exchanger, Turbulent flow