The schematic figure of a circular hydraulic jump is shown in figure. The vertical liquid jet impinges on the horizontal plate and spreads out radially, and the circular hydraulic jump is then formed. The phenomenon can also be observed in a kitchen sink and has been investigated experimentally and theoretically by many researchers.
There are mainly two types of circular hydraulic jump according to the eddy formed after the hydraulic jump. They are type I and type II jump. The Type I jump is the standard circular hydraulic jump in which the surface flow is everywhere radially outward. The interior flow is radially outwards everywhere except within a recirculating region just downstream of the jump (Tani 1949). The Type IIa jump is similarly marked by a subsurface ‘separation bubble’, but also by a region of reversed surface flow adjoining the jump. As the outer depth increases further, the jump transforms into a Type IIb jump marked by a tiered or ‘double-jump’ structure. Recent experimental results show that the circular hydraulic jump can change into various regular polygonal shape by changing ‘d’ in type II.
