충돌 Jet에서 Rod 형상에 따른 유동특성의 PIV 계측에 의한 연구

The thermal load is a very important problem to be solved in many industrial systems including the electronic equipment. Impinging Jets have been known to provide a large heat transfer rates on surface for many years. The turbulence enhancement of fluid flow is requested for the efficiency elevation of heat transfer. A study on flow fields by rods attached to the wall surface as a promoter of turbulence enhancement has been carried out. The exact analysis on chracteristics of impinging jet field is requested to obtain the optimum design of the impinging jet system. By visualizing the flow field and processing the high digital image by computer, PIV can afford exact data on the velocity vector, kinetic energy, and turbulence intensity in the complex turbulence field. In this study, three kinds of rod shape such as square, triangle, and semicircle are selected as the turbulence promoter. Nozzle diameters are 10mm, 17mm, and 23mm. And the analysis of the flow characteristics due to the above rods is carried out at Re No. 2,000, 3,000, and 4,000 by PIV measurement. It is clarified that the rod setup is very useful to obtain the turbulence enhancement and the turbulence intensity according to the shapes of rod appears large in order of the shapes of rod such as square> triangle> semicircle.