Yasuyuki Yokono

Unsteady Viscous Flow Simulation around Turbine Blade

In this study, 3-D unsteady viscous flow analysis around turbine blade cascade is carried out to investigate basic physical process involved in the pressure loss mechanism. In this regard, the strategy of the present study is first to compare the predicted results with the experimentally measurable data to check the prediction ability of numerical method. As a consequence of that the computed results agree with the experimental results. Therefore computed results could be used for visualization of the overall flow behavior to gather knowledge about what physical phenomena are associated with the mechanism of pressure loss. Because all the experimentally results compared so far with the computed results are the final outcome of the cause. From computed results, it turned that structure of vorticity from suction side and pressure side of turbine blade is a factor of pressure loss mechanism.

Flow Visualization of Heat Exchanger's Fins

Recent advancement of technology.need the compactness of heat exchanger to be used in the air conditioner without lowering its overall performance. It is well known that the performance of heat exchanger can be improved by introducing slits on the fin. However, the important problem here, is to choose the best possible slit pattern. In order to study the above mentioned problem, in the present work, experiment is carried out by using 10 times enlarged model fins of heat exchanger for flow visualization.Results indicate fully developed laminar flow pattern in the case of flat parallel plate. In the case of alternative arrangement of the slits, it is observed that the flow is symmetrical downstream the second stage of alternative slit pattern. Comparison of the experimental flow pattern with the calculated heat transfer coefficient lead to the understanding that downstream the second stage, if slits are arranged in such a way that the flow interact with the slits in the portion where the flow velocity is high, it is possible to increase the heat transfer coefficient.