Simulation On Flow Field Of Inverted Arch Cushion Pool And Experimental Study On Vibration Characteristics Of Slabs

The stability of a water cushion pool by the action of high water head and large flood-discharge power is one of the key technologies which relate to its safe operation. The development of flow conditions evolving from a free impinging jet in a simplified stilling basin, into a submerged impinging jet and further into a surface current and the corresponding flow-fields by high water and large discharge are simulated in 2-d k-e turbulence model to get regularities of distribution of streamline, velocity, hydrodynamic pressure and turbulent energy and turbulent dissipation rate. The flow field of an inverted arch pool by the submerged jet condition is simulated in 3-d k-e turbulence model to get regularities of distribution of streamline, velocity, hydrodynamic pressure, turbulent energy and turbulent dissipation rate. From comparison of results from the measured results with those from 3-d one, it is shown that simulation on the flow field of the inverted pool by using 3-d turbulence model is feasible.Comparison of results from 3-d model with ones from 2-d model shows that the pressure at shock point computed from the former is evidently less than that from the latter, and that characteristic variables are more uniform. Thus, the stability of theinverted pool is obviously superior to that of the flat bottom cushion pool. By making theoretical analysis of the vibration characteristics of a slab set in arch ring, a formula on its maximum free displacement, a division of slab vibration and a subdivide of flow field near the wall are proposed. Equations of dynamics of a slab installed in both types of cushion pool are analyzed and compared to arrive a conclusion that dynamic properties of slab in the inverted arch ring is superior to those of the flat bottom.Study on the vibration properties of a single slab and five ones set in a inverted arch ring is carried out to propose a division of vibration along water flowing, that is, three strong vibration areas and two weak ones, and give the vibration properties and the distribution laws of characteristic variables, which will be very significant for research on the unstability mechanism of inverted arch slab.