| Water resources are serious shortage in the northern area of China, but it can't be utilized reasonable for existing water resources, such as the utilizing of multi-slit and flood. Since this it is possible to utilize flood to research the new hydro-automatic roller gate which works automatically with the balance of driving moment engendered by water pressure, and returning moment engendered of self-weight and matched weight. And it has been proved feasibly by hydraulic-model experiment. It can be ensured opening and closing automatically while silting in front of gate. So it is important to calculate the force which acting on gate for designing gate exactly. The force can be calculated before gate opening. However, the hydraulic pressure can't be calculated after opening, and the formula hasn't been found. So the hydraulic characteristics of roller are studied by experimental, numerical simulation and theoretical methods in this paper. The main contents are as follows.(1) By the hydraulic model experiment, the change rule of roller surface's time-averaged pressure and hydraulic pressure are analyzed in different jaw opening and upper level conditions.(2) To establish mathematical model according to physical model, hydraulic characteristic of transverse roller surface are studied through numerical simulation. Ultimately, The RNG k ?εturbulence model and volume of fluid method (VOF) are applied to simulate the flow around transverse roller in this paper.(3) Numerical simulation is applied to simulate the conditions that physical model experiment can't carried out. the influence of jaw opening(h), roller top water depth(h1), upstream water depth (H)and roller radius(R)to around flow and hydraulic pressure of roller surface is analyzed.The main results of physical model experiment:(1) The hydraulic pressure presents the trend that increasing in the beginning and reducing afterward along the roller surface. When upper level is above the top, hydraulic pressure reaches maximum atφ=135°, hydraulic pressure is less atφ=0°andφ=180°, the bottom's hydraulic pressure is less than the top's.(2) When h is definite, roller surface's hydraulic pressure increases gradually with upper level H increasing. H is definite, the hydraulic pressure in 0<φ<90°isn't obvious change. While the hydraulic pressure in 90°<φ<180°reduces along the roller surface adown with h increasing. And the trend is obvious atφ=135°. The basic frequency of pulsation pressure is about f=50Hz. The Pulsation amplitude is maximal atφ=0°and atφ=45°pulsation amplitude is minimal. and in 90°<φ<180°extent, the pulsation amplitude of basic frequency increasing along the roller surface adown.The main results of numerical simulation: (1) The velocity reduces minimum at center line of roller, roller top and bottom's velocity is relative great. The velocity of above center line increases with h1 increasing. At back surface, the velocity of above center line increases with h1 increasing, and its change is complicated.And the velocity of back side is greater than water wind.(2) With H rising, The hydraulic pressure of water wind increases and reach maximal atφ=135°, then rapidly decreased. At roller bottom, the hydraulic pressure reaches minimal and appears negative pressure zone. At back surface, the pressure is relative small; the hydraulic pressure presents the trend that increases in the beginning and reduce afterward along the roller surface adown, and the change gradient enlarge gradually.(3) The pressure and R is in direct proportion at water wind when h and h1 are definite. At back side, the pressure and R is in inverse proportion in 220°<φ<260°domain.(4) The formula of transverse roller surface's hydraulic pressure is established through the result of physical model experiment and numerical simulation. And the results of calculational model are verified, it is comparatively exact.
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