Enhancement of an impingement heat transfer between turbulent mist jet and flat surface

摘要

The work presents the results of numerical investigation of the flow structure and heat transfer of impact mist jet with low concentration of droplets (M_(L1) ≤ 1%). The downward gas-droplets jet issued from a pipe and strikes into at a center of the circular target wall. Mathematical model is based in the solution to RANS equations for the two-phase flow in Euler approximation. For the calculation of the fluctuation characteristics of the dispersed phase equations of Zaichik et al. (1997) [35] model were applied. Predictions were performed for the distances between the nozzle and target plate x/(2R) = 1-10 and the initial droplets size (d_1 = 5-100 μm) at the fixed Reynolds number based on the nozzle diameter, Re = 26,600. Addition of droplets causes significant increase of heat transfer intensity in the vicinity of the jet stagnation point compared with the one-phase air impact jet.