Experimental investigation of the influence of flow rate pulsations on the rivulet flow regime

Abstract

The influence of flow rate pulsations on the rivulet flow regime has been investigated. The experiments were carried out on the underside of a smooth polyethylene plate. The investigation has shown that the influence of flow rate pulsations on the stream patterns is determined by flow peculiarities in the steady-state regime. Disturbances arising from pulsations of liquid flow rate can affect the stream liquid pattern of the rivulet. Such disturbance can cause the development of latent instability at individual points situated along the length of rivulet. The greatest effect on the stream structure is observed for the flow rate pulsation at liquid discharge with the ambiguity of rivulet regime. If the flow rate pulsations affect periodically the meandering rivulet, then it is possible to reduce the degree of meandering and convert the stream into the straight rivulet. In the regime of unstable meandering, it is impossible to identify correctly the effects caused by the flow rate pulsations at the initial area of the rivulet because of great self-acting pulsations of flow rate appearing in different sections along the rivulet.