Experimental Study On The Law Of The Soleplate Fluctuating Pressure And Its Conversion Of Point And Area In The Hydraulic Jump Region

Our country is a nation with rich water conservancy resources, in the process of development and exploitation of water conservancy resources, particularly high head hydraulic structures'design, construction and research, we usually meet a high velocity flow problem. So fluctuation pressure caused by the high velocity flow is a problem that we have to go deep into a research, it all has the problems with such as vibration, cavitations'erosion, energy dissipation and erosion, scour etc. Because of the complexity of actual engineering, the side wall fluctuation pressure problem in most engineerings can hardly beg solution with the theories analysis' method, usually from experiment measurement. The method which combines together with theories analysis through a physical model is a kind of valid method which work outs the pressure problem of the water current fluctuation.Because we need to make sure some area's dynamic water load in the actual engineering, but the direct measurement of area fluctuating pressure be very difficult, therefore, people try to establish the relationship of point fluctuating pressure and area fluctuating pressure. The research which with people have already done a great deal of work in recent years, got some beneficial conclusions, this text will study the conversion of point fluctuating pressure and area fluctuating pressure through a model experiments on the basis of other people's study result. Moreover fluctuating uplift breakage which have close contact with the fluctuating pressure is also currently our concern of the safe problem of flood releasing structure, so it is also the content which is worthy of thorough research. This text'main contents are as follows:(1) On the basis of different Fr number, under four kinds of work condition, we arranged respectively 0.2mm, 0.5mm two kinds of plate gap structure.(among them work condition 1 additionally set out the plate gap with 2 mm).we analyzed fluctuating pressure characteristic of the top surface and bottom surface, got the value characteristic along the plate middle line , relativity characteristic and frequency characteristic.(2) Under four work conditions (the plate gap with 2 mm), we measured some point fluctuating pressures and area fluctuating loads on the top and bottom of soleplate where the fluctuating pressure strength is probably biggest in the hydraulic jump region, analyzed the conversion coefficient of point and area fluctuating pressure's strength value, got the empirical formula, expained its rationality by comparing with actually measured conversion coefficient. Additionally it gave the actually measured conversion coefficient of the point and area fluctuating pressure's extremum value.(3) Respectively it analyzed frequency chart of point and area fluctuating pressure on the top surface and bottom surface, demonstrated the difference between them, and got the transform regulation of the correlation coefficient of point and area fluctuating pressure's frequency chart on the top of surface and bottom surface.(4) Under four kinds of work condition, we measured the area loads and its'resultant force and fluctuating uplift where the fluctuating pressure strength is probably biggest.with correlation analysis and area resultant force's positive load probability statistics, it analyzed forming reasons of fluctuating uplift; compared the theory value of fluctuating uplift with actually measured value, analyzed the frequency characteristic of area loads and fluctuating uplift at last.