Effects of flow condition and chute geometry on the shockwaves formed on chute spillway

Shock waves have undesirable effects, such as excessive dynamic pressure on spillway walls and the extension of flow beyond spillway conduits. To eliminate these detrimental impacts, designers have attempted to detect the characteristics of these waves. Flow interaction with chute piers generates triple waves in the middle walls and sidewalls of spillway conduits. The present study quantitatively investigated the characteristics of these waves with respect to variations in the bottom inclination angle (θ), wall contraction (w), and Fr numbers (Fr0). The results indicated that with the increment of θ, Fr0, (w, Fr0), and (θ, Fr0), the height (Hm) and distance (ls) of the first wave (w1) increased, which can be helpful for flow aeration. Furthermore, owing to a boost in θ, Fr0, (w, Fr0), and (θ, Fr0), the height of the second wave (w2) was decreased. Therefore, the amount of dynamic pressure on the spillway walls was reduced. Moreover, the distance of w2 decreased with a rise in θ, w and increased with the increment of Fr0 and (w, Fr0). As for w3, raising w and (w, Fr0) elevated the height of this wave and declined its distance. An increase in the height of w3 boosted the flow turbulence and aeration.