Numerical Assessments of Impingement Flow over Flat Surface due to Single and Twin Circular Long Water Jets

Abstract

Hydrodynamics of impingement flow is a key partner of heat transfer analysis of run-out table (ROT) steel cooling. Velocity and pressure profiles before and after impingement of long circular free-surface industrial water jets (Re = 16,669-50,068) was numerically studied and also wetting front propagation and size of impingement zone were computed. The turbulent models represented impingement water flows over surface better in good agreement with the experimental data at the ROT facility. Higher velocity gradient was obtained for long turbulent jets indicating enhanced heat transfer at impingement zone. The effect of local pressure on saturation temperature changes predication of boiling heat transfer correlations up to 9% which is noticeable for ROT cooling. Impingement zone was found smaller respect to the estimation used in ROT modeling obtained from short jets experiments. For twin jets, simulation show calm interaction of low flow rate water jets with no splashing in accordance with the experiment. Water film thickness in interaction zone is elevated toward jet-jet axis.