Study On Numerical Simulation Of Vortex Board's 3-dimension Interior Field Distribution

Vortex tube is a simple device which can bring into Ranque-Hilsch effect, i.e. compressed gas was separated into cold and hot flow simultaneously. The features of simple structure, non-moving parts, convenient maintenance, and credible operation were existed in vortex tube. Until now, applications were in many aspects such as refrigeration, air conditioning, separation of natural gas, mechanical process. However, its disadvantages of low efficiency and less refrigerating output limit it's more extensive applications.In this paper, by numerical simulation on work process, characters and structural performance of the vortex tube, distribution of interior field function was analyzed, and mathematical model was constructed by combining Thermodynamics, Heat Transfer Mechanism and Fluid Dynamics. By using CFD software packs on numerical simulation, energy separation theory was improved from pure vortex tube to integrated vortex tube (vortex board), and then introduced discussions of structural character of vortex board.First of all, thermodynamic model of vortex tube was constructed as hypotheses of friction force resistance flow and adiabatic throttle flow, and Ranque-Hilsch effect was further verified by thermodynamics and entropy analysis. Energy transfer from cold gas flow to hot gas flow was implied by considering radial energy transfer theory. The kinetic energy became into heat because friction force cause gas swirl nearby the wall of vortex tube, as well as exhausting heat was transferred into hot gas flow. The kinetic energy and internal energy increased, total entropy exceeded that of inlet gas. So hot gas flow exhausted in hot end, and cold gas flow exhausted in cold end.Secondly, conception of vortex board was introduced, the numerical simulation was implemented on vortex tube (vortex board also), numerical simulation method was verified of valid by compared with experiment results. In an admirable error bound, the numerical simulation had the close results with experiment by the characteristic curve of cold mass flow fraction, as well as Thermodynamics model of vortex tube (vortex board also), So Thermodynamic theory hypothesis was available to explain Ranque-Hilsch effect of vortex tube.Finally, interior field function distribution of vortex tube (vortex board also) was obtained by the numerical simulation. Plenum chamber was regard as constant press volume. When multiple vortex tubes were arranged inside of the given plenum chamber, total mass flow rate of vortex board increased, characters of interior field function distribution of plenum chamber would be disturbed. The existing plenum chamber had the full impact on distribution of interior field function in vortex tube (vortex board also).Therefore, the location of vortex chamber inside plenum chamber was a key factor to influence interior field function distribution on transverse profile of nozzles, and configuration of nozzles on inside plenum chamber was secondary factor to influence interior field function distribution on transverse profile of nozzles.