Experimental investigation on impingement of a submerged circular water jet at varying impinging angles and Reynolds numbers

Based on the particle image velocity (PIV) and pressure measurements, an experimental investigation has been made to study the flow characteristics of a fully developed submerged pipe jet impinging on an impermeable plane at a constant jet-to-plane distance of H/D = 3. This study focuses on the velocity distribution in the free-jet region and the flow structure in the impingement region at different impinging angles (0 ≤ θ ≤ 90°) and Reynolds numbers (11,700 ≤ Re ≤ 35,100). Moreover, the development of the deflected wall jet in terms of the maximum velocity decay and the half width, as well as the jet-induced hydraulic pressure on the plane, have been presented. The energy loss of the jet in the process of impingement is found to increase with θ, while the mean velocity distributions and the hydraulic pressure coefficient show little variation with Re, indicating that the flow is highly dependent on θ and but is relatively independent of Re within the examined range.