Abstract
In recent years, the further improvement in the cooling technology in narrow space is needed for the integration of apparatus, and the miniaturization of apparatus. Consequently, we focused on the single round impinging jet which is one of the fundamental cooling methods. Impingement jets have been widely used for cooling and heating on a surface of a body in the industrial fields, because the high heat transfer coefficient is obtained near the stagnation point where the jet struck. This paper present the characteristics of flow behaviors and thermal fields of the impingement jet issued from the circular orifice nozzle of D=30 mm in diameter. The experiments were performed for the separation distance, H, between jet exit and impingement plate in range from H/D=0.5 to 4, for Reynolds number in range from 1600 to 6600. The flow behaviors of the impingement jet were observed by the smoke flow visualization recorded by a high speed camera using 5000 frame per second. The heat transfer coefficients on the impingement surface were measured by means of an infrared camera. Particularly, we investigated the effect of the flow behavior on the heat transfer in the narrow space. From the result of these experiments, we showed the effect of the jet flows on the heat transfer.
