Control of Impingement Heat Transfer Using Mist

Abstract

Impingement heat transfer enhancement from a circular orifice jet by using latent heat of water mists was studied experimentally. M i s t s w e r e added near the orifice edge within a range of which liquid films were not formed on a target plate. Adding mists hardly influenced free jet mean velocity profiles and target plate pressure coefficients. On the other hand, mists had a strong influence on temperature and humidity profiles of a free jet and the also influenced Nu distributions on the target plate. Increases of mists and Re caused increases in Nu on a developed region. Moreover, we investigated the influence of the way were added mists, and results showed that Nu was varied not only by the amounts of mists but also by adding method. Local Nu profiles with mists were closely related with temperature distributions of the free jet at the corresponding location of the target plate.