Experimental study of the critical submergence for double-layer intakes

Empirical hydraulic engineering formulas for the critical submergence are applicable only to single intakes. This study analyzes the critical submergence for double-layer intakes using hydraulic model tests with an equivalent pipe size used to correlate the critical submergence for double-layer intakes. The results show that the critical submergence for double-layer intakes is larger than calculated Gordon's empirical equation, but the slopes are similar. Thus, Gordon's correlation should only be used with single intakes with the current empirical correlation useful for double-layer intakes.