Experimental Investigation of Effect of Inlet Froude Number on Turbidity Currents Behavior over Obstacles

Density currents are formed when gravity acts upon a density difference between two various fluids, and the driving force is the buoyancy force. The streaming of particle laden fluid is called turbidity current and this kind of currents is the major mechanism for sediment transportations in lakes and seas. In the present study, the main concentration is on the effect of inlet Froude number on the behavior of a turbidity current passing over an obstacle and a series of laboratory experiments were carried out including an acceptable range of Froude number from subcritical tosupercritical.The obstacle has an isosceles right triangular crosssection and a height of 10 centimeters. In each experiment, velocity profiles in the body of the current were measured, using anADV (Acoustic Doppler Velocimeter).The investigations showedthat the current with lower inlet Froude number senses the influence of the obstacle more rapidly compared to the currents with higher values of Froude number.Also the local Froude numbers has an abrupt increasewhen the dense layer passes the obstacle

کلیدواژه ها:

turbidity current ، obstacle ، Froude number ، velocity profiles ، experiment