Hydraulic jump is an important phenomenon in water resource engineering. Present study involves linear stability analysis of St. Venant equations for hydraulic jump in an open channel under steady flow conditions. Frequency of perturbed flow is studied numerically with respect to flow depth and Froude number (Fr). It is observed that angular frequency (ω0) of flow achieves the peak at critical Froude number Fr = 1. Effect of roughness coefficient and bed slope on the frequency of the flow reveals that frequency peak increases with roughness coefficient, but an increase in bed slope reduces the frequency. Further, study of the characteristics of angular frequency (ω0) and wave number (k) of hydraulic jump shows the stability in supercritical, subcritical and critical flow regimes. The study shows the propagation of perturbations in different flow regimes and the effects on the stability due to influence of roughness and slope.
Jiwane et al. (Sun,) studied this question.