| Since our country founded, large numbers of hydraulic projects have been built. Withthe improvement of worker's techniques of the dam and the development of the hydraulicand hydroelectric construction, the hydropower projects with high water head and largedischarge keep continually increasing, of which the flood discharge and energy dissipationstructures are indispensable parts.However, ski-jump dissipation is the most common-usedtype in high water head water release structure. In order to get the water jet, current ways ofski-jump dissipation (besides aerated baffle ski-jump dissipation) all use the method ofchanging the geometry of the bottom slab and the sidewall to change the shape of the crosssection. Among all these kinds of current ski-jump dissipation ways, impact-type ski-jumpdissipation, which is more flexible, takes advantage of the impact force between the streamand the pier to make the stream reflect and become a jet flow. At least, it could be an alternateway among the new-type ski-jump dissipations. The main purpose of this paper is makingsome explorations on a new ski-jump dissipation way—impact-type ski-jump dissipation.First of all, this paper makes a detailed analysis on existed kinds of simplified formulasof shock wave, presents the applicable conditions of every kind of simplified formulas; makesa theoretic study on the shock wave with deflective or gradient sidewall, and deduces thecalculation formulas accordingly, also experimental verified, good agreement is attained, thispaper makes a theoretic analysis on the problem of the differences resulted from theapplication of the ideal shock wave and actual water flow phenomenon, here are the reasons:①Generally, the original part of actual shock wave isn't zero-thick, so the real flowinggraph is more complex than calculation schematics, also it's impossible to determine thethickness of that part only using the equations of the mass conservation and energyconservation;②When the value h2/h1 can't be omitted and the original part has a certainthickness, the flow particle gets an vertical component, unforgettable, or it will cause certainerror;③Whenαbecomes bigger,Fr1 higher,the length of the deflector restricted, thepressure of the stream doesn't obey the rule of pressure distribution of the still water in theback of the wave.Second, Convenient for practical use, there are tables of different states in differentdeflector angles, different slopes, different deflector angles corresponding to the Froudenumbers of coming flow and different ratios of the down-stream flow depth to the upstream flow depth in common, based on theoretical formulas. Also graph of Fr1-α-β-h2/h1-Fr2in caseθ=30℃,θ=40℃,θ=45℃,θ=50℃,θ=60℃,θ=70℃,θ=80℃,θ=90℃θis the slope angle.Third, based on the theoretical formulas of the shock wave with deflective sidewall,when the height of the wave is small enough, h2≈h1,friction force and energy loss omitted,formula 1 obtained using integration, this formula is applicable in case of smooth slope; Toget simplified formula 2, Micro-shock wave is developed by Taylor series in the hypothesisthat Es=cons tant, with the high order infinitesimal neglected. This formula has a simpleform, but it brings obvious error in the deflector angle in comparison to the original formula,due to the neglect of the high order infinitesimal, still applicable for project use. Simplifiedformula 2 is applicable to common artificial rapid flow channel, when the deflector angle ofthe sidewall is small, this formula also can calculate sharp shock wave. Convenient forapplication and reference, there are tables of different states in different deflector angles,different shock angles corresponding to the Froude numbers of coming flow and differentratios of the down-stream flow depth to the upstream flow depth.
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