Numerical And Experimental Investigation On Impinging Of A Submerged Water Jet At Varying Parameters

Submerged water impinging jet is a classical jet flow,which widely exists in various engineering movement backgrounds,such as helicopter takeoff and landing,irrigation and drainage engineering,cooling and heating processes.However,the flow state of submerged water impinging jet is complex and has many influencing parameters,which has important academic value for its research.In this paper,the flow field characteristics and impinging pressure of submerged water impinging jet are analyzed by means of numerical simulation and experimental research.The internal flow field characteristics of submerged water impinging jet with different geometric parameters(impinging angles?,jet-to-plane distance H,Reynolds numbers Re)are studied.The main results are as follows:(1)The results of submerged water impinging jets with various impinging angles(15°???90°)show that the flow is highly dependent on the impinging angle?.With the increase of the impinging angle,the velocity of the jet reaching the impinging region decreases,the lateral diffusion degree of the wall jet increases,and its thickness decreases gradually.The maximum impinging pressure on the impinging wall increases gradually with the increase of impinging angle.,and its position is closer to the impinging origin.The maximum pressure coefficient Cpmax is found to grow linearly with the critical normal velocity of the jet just entering the impinging region.The pressure coefficient C_p along the plane mainly concentrates on the impinging region in the range-2?x/D?2,and the concentration of pressure on the upstream side of the maximum pressure point is higher than that on the downstream side.(2)The results of oblique impinging jets(?=45°)with different jet-to-plane distance show that the flow field of oblique impinging jets at different heights is similar.With the increase of impinging heights,the whirlpool strength of oblique impinging jets decreases gradually,and the maximum pressure coefficient on the impinging wall decreases linearly.(3)The results of horizontal impinging jets with different horizontal heights show that the distance from the jet diffuses to the wall is linear with the horizontal height.When the jet diffuses to the wall,its vertical diffusions change into transverse diffusions,and the velocity distribution near wall region changes significantly.(4)The analysis of the results of impinging jet and horizontal jet under different Reynolds number shows that the dimensionless axial velocity distribution curve is similar under different Rayleigh numbers,the pressure coefficient distribution on the impinging wall is consistent,and the flow is similar.