Abstract

Scouring around spur disk head belongs to local scouring problem around regulation, and that will concern on the safety of the regulation directly. This paper starts from the physics essence of local scouring around spur disk: the function of circumfluence around spur disk head. The incidence of circumfluence around spur disk head to the flow field at transverse section is general 3–5 times longer than effective spur disk length according to the theory of hydrodynamics and the width of scouring hole commonly is less than the effective length of spur disk. The analysis shows that if the conditions are the same except the section form in upper reach of the spur disk, the scouring holes around spur disk head are also different, especially the natural riverbed composed with a certain content of thin particle. Obviously, the local scouring formula that can fully represent those influence reasons will be very practical. Based on the mode of circumfluence press flow around spur disk head and started from the principles of current continuity, corresponding formula, which is used to estimate the scouring depth around the spur disk head, is set up. And through the comparison between the results with formula, field data from Yellow river and experiments, it shows this formula is beneficial.

Keyword: spur disk, local scouring, the mode of circumfluence press flow