The distribution of particle phase concentration in two-phase flows in avertically set duct can be studied by using two-fluid model or diffusionmodel. The same result ``npv′2p=constant'' is deduced fromboth models.rn In the two-fluid model, the principle of force equilibrium is appliedfor each phase. In a steady fully developed pipe flow the inertial forceis zero and there are no other external force on particle phase alongthe transverse direction besides the particle partial pressure caused bythe fluctuation of particles, so a zero gradient of particle pressure,i.e. mp npv′2p=constant, can be resulted from the momentumequation.rn In the diffusion model, the concentration distribution is determined bydiffusion process. For an steady fully developed pipe flow, anequilibrium among the diffusions caused by various diffusion potentialsis reached. There are two main diffusion potential: concentrationgradient and fluctuation intensity gradient of particles. Theequilibrium between the two diffusion potentials means 1np npy+ 1v′2p v′2py=0. Then the same result as in two-fluid model``npv′2p=constant'' is deduced.rn Using two-phase velocity separation technique of LDV, the distributionsof averaged velocity, the steamwise and traverse fluctuation velocitiesof each phase and the relative concentration of particles in aliquid-solid concurrent upward flow in a vertically set duct arecompleted. It is confirmed that the traverse concentration distributionof particles in fully developed sections depends mainly on thedistribution of the intensity of traverse fluctuation and that``npv′2p=constant''.%利用激光多普勒分相测量技术,考察了液固两相自下而上通过竖置矩形管时,固、液两相的时均速度、流向及横向的脉动强度和颗粒相的相对浓度分布,证实了颗粒浓度的横向分布主要取决于颗粒的横向脉动强度分布(即np v′p2=常数)的分析结果.
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