Abstract
A study of cooling by a single water jet impinged on the horizontal flat plate had reported in the previous paper. In this paper, the mean coefficient of heat transfer between 9 jets, which were held in square array, and the surface of plate are measured in wide range. The radius (γ_j) of the hydraulic jump and the thickness (δ_<m2>) of water film were measured, and observed that the former became smaller and the latter varied thicker with respect to the reduction of nozzle distances respectively. The experimental formulae about γ_j, δ_<m2> were obtained by the data above mentioned. The mean coefficient of heat transfer of single jet based upon square area of plate was computed by the theoretical treatment. It was found that the theoretical equation of heat transfer rate about the single nozzle could be applied to the case of multi jets. Furthermore, the jet was impinged against the limitted area constrained by dikes, which was considered as if the simulation instead of actual multi nozzles experiments. The value of heat transfer rate and the radius of jump in this experiment so-called "simulation" were coincided with the data of the actual multi jets.
