Application Of Large Eddy Simulation In The Characteristics Of Fluctuating Pressure On Structures Of Overlapping Layout

Fluctuating pressure, which closely related to the safety problem of vibration,cavitation, energy dissipation and erosion control of hydraulic structures, is a concernparameter in practical project research. Guide wall and floor of stilling basin are theextensive concern of the key position of research on discharge and energy dissipation.In fact the partitions on dam surface in front of the stilling basin should be also keyobject in research of building security and stability. However, there is few relatedresearch so far. Therefore, the paper study on the characteristics of fluctuatingpressure on dam partitions between discharge structures of overlapping layout byusing large eddy simulation method. Specific content as follows:1. Base on the generating mechanism of fluctuating pressure and PossionEquation which is the derivation of Navier-Stokes Equation, the paper provides aresearch method of combining quantitative analysis of influencing factor such asfluctuating velocity, velocity gradient, fluctuating vorticity and qualitative analysis ofthe characteristics of fluctuating pressure.2. A numerical simulation of large eddy simulation which used in thecharacteristic research of fluctuating pressure on dam partitions between dischargestructures of overlapping layout is achieved. The validation between calculatedresults and test data shows the method of large eddy simulation is feasible.3. Base on the numerical simulation results and test data, vertical fluctuatingpressure distribution is analyzed. It is show that the largest fluctuating pressureintension occurs in the headpiece partitions of surface hole, but in the deep hole thelargest fluctuating pressure intension occurs in the middle part of partitions.4. Through the further analysis research of numerical simulation results,influencing factors of fluctuating pressure are sought out which are fluctuatingvelocity, velocity gradient and fluctuating vorticity. Then it is proposed that thecombining action of fluctuating velocity and velocity gradient mainly impactfluctuating pressure distribution on partitions of surface hole, and the self-action offluctuating vorticity mainly impact fluctuating pressure distribution on partitions of deep hole.5. Fluctuating pressure distributions of different downstream water level areprovided. When the water level is middle level, fluctuating pressure intension ofsurface hole is largest. The lowest water level and highest water level do not result inlargest fluctuating pressure intension. The self-action of fluctuating vorticity canexplain fluctuating pressure distribution.6. Two working condition have been simulated, which are only surface holesdischarge and combining discharge. The numerical simulation results show thatfluctuating pressure value of surface hole is larger in the working condition ofcombining discharge. It proves that deep hole discharge can impact fluctuatingpressure distribution in surface hole.