Experimental Study On Navigation Flow Conditions At Navigation Building Approach Channel Of Winding Canyon River With Generalized Model In Wujiang River

Wujiang River belongs to a classical winding canyon river.Because of the winding ,the layout of straightway is restricted,the plane layout of approach channel is mostly arranged for antisymmetry and curve profile;Because of the canyon ,most of the skew angle of tail water channel to lower river are 40 to 60o,which seriously influences the flow condition at the entrance area in low-water season.The article analysed and summarized the condition and characteristic of navigation building in Wujiang River by collecting the information of hydro-power station in Wujiang River.Based on the backing engineering at mostly junctions of Wujiang River,the hydro-power station model for the winding canyon rive was sets up and the influence of the length of guide channel and the skew angle of tail water channel to lower river and the distance of the dam axis to the curved conduit on navigation flow conditions were studied.The research disclosures the length of the approach wall influences the navigation flow condition more seriously compared to else.When it is short excessively,the intension of the circumfluence and lateral oblique flow very strong in low water period.Per contra,the intension of the oblique flow very strong in flood period;When the approach wall locates straightway,opened pore on the approach wall and extended on the head of the approach wall can improve the navigation flow condition at the entrance area;The influence of the skew angle of tail water channel and lower river on navigation flow conditions is serious,and the skew angle suggested is no more than 40o;The longer the straightway of the approach channel is,the shorter the length of the approach wall needed,the length suggested of the approach wall is more than 363m.Meanwhile,the research disclosures that changing the length of downstream approach channel,head arrargement of flow partition wall,dike opening,minishing the skew angle of tail water channel and lower river and increasing the length of the straightway of the approach channel can improve the navigation flow conditions obviously.