Hydraulic Characteristics in Depressed Density Interface Induced by Vertical Impinging Jet

Abstract

Hydraulic characteristics inside the depressed density interface induced by vertical impinging jet is studied experimentally. The relationship between the integral time-scale and predominant period of interfacial fluctuation is found to be similar to the experimental result with oscillating grid. The most turbulent energy is occupied by the component of predominant period. From measurement of flow velocity, the intergral time-scale is proportional to Brunt-Baisala frequency and the predominant period. The characteristic length scale defined by the predominant period and turbulent intensity is almost identical to root mean square of interfacial fluctuation at the edge of interface and to nominal width of jet at initial position of interface. The characteristic length-scale mentioned above is closely related to the entrainment process at the edge of interface