Research On The Characteristics Of Flow Field & Energy Consumption And Effectiveness Of The Local Generator

Now, There are three kinds of means in the application of sand exclusion by spiral flow: the vortex tube sand exclusion, the sand funnel and the spiral flow in the horizontal pipe. The vortex tube sand exclusion was used to breed out the traction load that mains exist in the bottom of channel. The way of the sand funnel is according to the design of character of stream current, make use of separating mechanics of spiraling flow to breed out the sediment of the channel(suspended load and traction load). The spiral flow in the horizontal pipe can generate the spiral flow to transport sediment according to the way of equipping the guide blade in the middle of the pipe. The Preceding two ways have been used of engineering practice comprehensive, the spiral flow in the horizontal is a new way of energy-saving and high efficiency which proposed lately to breed out sediment, now it still in the experiment research phase. As a new way to breed out sediment, the spiral flowin the horizontal pipe has the advantage of high-concentration, energy-saving and no silting it overcomes the paradox of concentration and energy of sediment transportation in smooth flow.On the basis of model experiment, not only is the hydraulic characteristics of the spiral flow in the horizontal pipe locally generated preliminarily investigated by means of numerical simulation, but also is the structure parameters and resistance characteristic of the spiral flow generator which generates spiral flow in circle pipe analyzed and experimental investigation. The main research is as follows:1. In the rotation-starting pipe of the spiral flow in the horizontal pipe locally generated, the influence of boundary layer of guide blade is considered. Through researching the velocity distribution of the rotation-starting pipe(especially in the guide blade) ,it analyses the change status of boundary layer in the curving guide blade and studies the influence of the resistance of boundary layer on the spiral flow energy cost. Hence this article has proceeded the theoretical analysis about the change status of boundary layer and applied the numerical simulation to predict the development of boundary layer in the different position.2. It has proceeded the numerical simulation in the inner of rotation-starting pipe and considered the influence of turbulence effect. Based on the Navier-Stockes equation, which used velocityand pressure as arguments to compose the differential equation this paper adopts the Boussinesq assumption and uses the theory of mixing length to define the eddy kinematic viscosity and establishes the mathematical model about turbulence model. The finite difference method is applied to discrete the Reynolds stress equation on cylindrical coordinate system, the three-dimensional model with steady condition is established. It used moving and alternating difference method and utilized iterating method of Gauss-Seidel to simplify the computation process, finally the flow field information about the rotation-starting pipe was obtained.3. The stress of inner stream current has been analysed, it thinks that the resistance of inner generator is made up of three parts; tube wall shear stress, guide blade shear stress and guide blade resistance. In this paper, the stream current stress of guide blade has been analysed and the resistance loss of guide blade of the spiral flow in the horizontal pipe has been deduced. According to the analysis, it can determine the generator efficiency of different schemes and optimized the generator parameters. It provides the evidence for high-efficiency and low-energy cost generator scheme.4.It has researched the hydraulic characteristic locally generated through physical model experiment and obtained distribution characteristic of flow field produced by different schemes. At the same time ,it has tested the result of numericalsimulation. Comparison and analysis have been done between the result of numerical simulation and physical model experiment, the hydraulic characteristic locally generated has been o...