Investigation on flow characteristics effect on scour depth of two inclined jets impingement

Local scour of free fall jets due to destructive effects on hydraulic structures is an interesting topic for researchers. Impingement of 2 jet changes the erosive water power and also leads to air entrainment. In this research-based on experimental results, scour depth in the plunge pool due to two inclined jets impingement was investigated. Three sizes of sediment aggregate was used and tailwater was changed at four levels. Jets had three angles relative to vertical, namely 30, 45, 60 degrees. It was found that with increasing densimetric Froud number, the scour depth increases. Also It was found that with increasing jet angle, the scouring depth was increased. Some formulas presented by different researchers were compared to estimate the scour depth for impingement of the two inclined jet and a new equation for estimating of scour depth was proposed. Furthermore, the results showed that air entrainment had a significant effect on reducing scour depth.