DOI: 10.1615/ICHMT.2009.CONV
ISBN Print: 978-1-56700-261-4
ISSN Online: 2642-3499
ISSN Flash Drive: 2642-3502
NEW MEASURING METHOD FOR THE LOCAL HEAT TRANSFER IN MICRO-STRUCTURED HEATEXCHANGER CHANNELS
ABSTRACT
The work described in this article describes the development of a method based on induced fluorescence to measure the local height-averaged two dimensional temperature fields of micro heat exchanger channels passed by a water flow. The fluorescence signals of rhodamine B and sulforhodamine 101 solutions in water are detected in sequential experiments. For rhodamine B the fluorescence intensity strongly depends on temperature, whereas sulforhodamine 101 expresses little temperature dependence. With the additional information of the sulforhodamine 101 measurement, the influence of exciting light intensity can be eliminated arithmetically. In this way, diffraction effects due to diffraction index gradients are no longer present in the results. From the experimentally determined height averaged two-dimensional temperature fields and gradients in the fluid, heat transfer from the channel wall to the fluid can be determined analytically using a simplified one-dimensional model. The experimental results are compared with the results obtained by three-dimensional numerical simulations based on the Navier-Stokes equation and the energy equation with the program FIDAP.