The Investigation Of Solid Particle Distribution In Gas-Solid Two Phase Of Averaging Pitot Tube

Multiphase flow has been widely applied in sectors of the national economy of our country. As a typical pressure differential measurement instrument, the averaging pitot tube, with simple structure and high measuring accuracy, is applied to the measurement of two-phase flow, the multiphase flow theory, experiment and numerical research related to the averaging pitot tube are almost blank. On the basis of the prototype, with local venturi effect, the averaging pitot tube witch our research group study has higher efficiency output of pressure differential. The flow coefficient is lower by greatly amplitude and the effective measuring range is wider.The development history of the averaging pitot tube is summarized and the related characteristics of the gas-solid two-phase flow is concluded. To confirm the accuracy of calculation results and the rationality of time step, the models of grid, the turbulent flow and multiphase flow are chosen and the calculated results are compared with direct numerical simulation results. Finally the model parameters are determined, and fully developed flow velocity is equivalent processed.In this paper, the control equations of large eddy simulation, under the condition of sub grid turbulence model of dynamic Smagorinsky-Lily, are the Navier-Stokes equations via the cartridge filters. The anthracite coal particles are put in gas phase. The particle movement is under the framework of Lagrangian trajectory model. The particle concentration distribution under different geometric conditions and different sizes of the perimeter are detected. A concept of collision and wear is introduced. The wear model is set up and the bar wall erosion is studied. This paper is based on a large number of the numerical simulation of discrete phase gas-solid two phase flow. Conclusion indicates that enrichment effect occurs at high pressure hole area under turbulent flow conditions. It changes little with the change of speed and distance between bars. All particles of different Stokes number have concentrated distribution in the front of test bars. Large Stokes number particles distribute in most of the area surrounding the bar wall. Particle distribution between bars will change with the change of the Stokes number and distance. Larger Stokes number particles have a high concentration distribution at the static pressure hole area. This is the very reason causes the block. The erosion effect of particles will be changed by the changes of particle size, speed and distance. At the same time, the flow coefficient also varies with the Stokes number, flow velocity and distance.This paper preliminary detect the distribution of solid phase in the new averaging pitot tube of gas-solid two phase flow. It provides a certain reference in engineering application of discrete phase.