Critical Submergence in Two‐Layer Stratified Flow

Abstract

Experiments are conducted on circular, vertical intakes drawing from two-layer stratified sources. Arguments are presented to suggest that current definitions of critical drawdown, as the condition under which the upper layer is on the point of being drawn into the intake, are unnecessarily conservative. Instead it is suggested that 1% mixing is acceptable. Experimental results for capped and uncapped intakes are presented to compare these two definitions of critical conditions. It is shown that significant differences in acceptable flows or depths may occur depending on which definition is used.