Wave Breaking in Undular Bores with Shear Flows

Abstract It is well known that weak hydraulic jumps and bores develop a growing number of surface oscillations behind the bore front. Defining strength as ratio head undular to undisturbed depth, it was found in classic work Favre (Ondes de Translation. Dunod, Paris, 1935) regime laminar flow demarcated from partially turbulent flows by sharply defined value 0.281. This critical characterized eventual breaking leading wave Compared depth flume, waves developing front are long small amplitude, can be shown situation described approximately using Kortweg–de Vries equation. In present contribution, if shear incorporated into KdV equation, kinematic criterion used test whether spilling, then theoretically within an error less than ten percent.