| Today more and more water conservancy and hydropower construction projects, which with high-head and large-flow is increasing. Due to its discharge flow has tremendous energy, which causing a strong impact on the downstream river bed, so the design of high dam of the discharge structure in engineering applications is particularly important.Taking account of some of the traditional energy dissipator Stilling-to-bed flow can not meet requirements of the discharge. They designed a number of new energy dissipator based on the traditional energy dissipater. The step-down bottom energy dissipater proposed this new form. This new energy dissipater add a step-down on the conventional energy dissipation as reduce the elevation.of Stilling.Because of the step-down, Stilling pool of water flow has changed from the end of flow dissipation of conventional wall jet flow into the submerged end of state, also caused plunge pool energy consumption and changes in the distribution of turbulent energy. Eventually reach the mainstream of energy dissipation after the Stilling Basin significantly reduced the clinical bottom velocity, reduce its Stilling erosion damage. Therefore, the end sill or flow dissipation can not only reduce the stilling basin floor-to-bed velocity can reduce the hydrodynamic pressure, thereby enhancing its structural stability. At present, domestic although there will be examples of its application to practical engineering, however, the end of the sill or flow dissipation of a lack of systematic theoretical study.This paper, based on Natural Science Foundation of Yunnan (2006A0018M) standing to the subject. Experimental research in hydraulics, based on energy by changing into the pool, into the pool or Hom angle and depth of the three conditions, or sill dissipator flow stilling pools, both when the hydrodynamic pressure, velocity, hydraulic indicators detailed observation. In the test result analysis based on the theoretical analysis the following research:(1) analysis of stilling pool flow patterns in the variation and influence factors; (2) study the bottom currents flow under the stilling pool water movement structure; (3) Hom on plunge pool or depth, angle and plunge into the pool formula for estimating the length pool; (4) of the Stilling of cavitation and abrasion damage and the mechanism of, damage and material selection.This paper briefly introduces the basic conventional energy dissipator flow phenomena and the movement mechanism and a detailed analysis or sill dissipation dissipation mechanism. To flow analysis and the depth of analysis or Hom, into the pool of energy, the angle of the plunge into the pool flow pattern of pool. And the test data, the above factors taken into account based on the bottom of the sill or flow dissipation stilling basin shape optimization. While in the theoretical analysis and experimental combined with the results analyzed based on the down sill dissipation workers of the hydraulic characteristics, invert the submerged bottom currents flowing down sill dissipator control equation and the plunge pool or Kan depth formula, and determine the submerged bottom current flow patterns for engineering design or Horn depth range. Calculated the length of stilling basin. On the failure mechanism of the Stilling Basin based on the analysis of the Stilling material selection. |
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