Numerical Simulation Of Interior Flow Of Jet Pump To Use Monte Carlo Method

Jet pump is a kind of fluid machinery and mix reaction equipment with fluid jet as working medium, which transfers energy to suction fluid through turbulent diffusion of fluid particle. Jet pump has been used in many department of national economy, and naturally a new subject called 'jets technology' is formed. The theory is eomplicated thought the simple structure of jet pump. With the development of compute technology numerical simulation is one of the main methods for studying fluid field inside jet pump. This paper investigates jet pump using Monte Carlo method (MCM), and the major contents are as follows:First, the working principles and study literatures are reviewed, then a general Introduction of common computation methods of hydromechanics, followed by MCM history and this paper's study purpose.Second, a detailed description of MCM basic idea and characteristic and principles is given, which tells how to solve two-dimension elliptical partial differential equations using MCM and how to realize it on computer.Third, sums up several specific formulas of fluid continuity equations and momentum equation under right-angles coordinates and axis-symmetric poles coordinates. The turbulent diffusion coefficients computing formula is obtained based on the turbulent characteristic and turbulent analysis theory with observed data.Fourth, numeric computation of fluid field inside jet pump is conducted with continuity equation and momentum equation of steady fluid under right-angled two-dimension coordinates, and the random walk model is given. As for nonhomogeneous equation, the method of integrating coupling pressure and momentum equation is adopted. The results is near the outcomes of solving homogeneous equation under the same boundary conditions. Furthermore, the relation of random walk times and computing time and computing errors is analyzed in-depth. Firth, numeric computation of fluid field inside jet pump is conducted with continuity equation and momentum equation of steady fluid under axisymmetrictwo-dimension coordinates, and the random walk model is given. As for nonhomogeneous equation, the method of integrating coupling pressure and momentum equation is adopted. The results is near the outcomes of solving homogeneous equation under the same boundary conditions. The modeling results demonstrate consistence with laser Doppler anemometry (LDA) observed data.Sixth, based on previous work of inner fluid state of liquid gas jet pump is analyzed synthetically. And the fluid state can be separated into three stages.Seventh, the definitions and classification of two-phase and multi-phase fluid are introduced including their developing history. And multi-phase fluid study methods is also discussed and how to use it in fluid field computation of jet pump. This chapter puts forward computing method of fluid drip and bubble diameter. Random movement of bubbles in jet pump is compared to random sediment of solid particles in fluid and movement state of bubbles inside jet pump is analyzed based on the same principles. Under a simple assumption, an illustrative case is studied to give moving probability of bubbles along the axis and radial direction and fluid trajectory in jet pump. Euler method and lagarange method are combined. This indicates that gas can be seen continuity medium with fluid drips regarded as dispersed particles, or liquid can be seen continuity medium with gas bubble regarded as dispersed particles. So the numerical simulation of fluid field in liquid gas jet pump is formed.Finally, this paper sums up the whole content, and suggests some new ideas and methodology for future study.