BINGHAM流体环空管流流动及传热规律研究

结合BINGHAM流体的本构方程、管流运动方程及能量方程 ,推导了BINGHAM流体环空管流速度分布及温度分布。由于BINGHAM流体具有屈服值 ,环空管流流动中会形成流核。流核的宽度与屈服应力成正比 ,与广义压力梯度呈反比。流核中心线偏离环空中心线 ,且偏向环空内侧。环空内外径之比越小 ,相对偏离越远。在其他条件不变的情况下 ,当屈服应力增大时 ,速度分布剖面变得愈扁平。当其他条件不变时 ,流核速度随环空内外径之比减小而增大。流核内温度变化比环空内外侧明显小 ,随屈服应力的增大 ,温度分布剖面愈扁平。

Research on Flow and Heat Transfer Law for Annular Pipe Flow of BINGHAM Fluid

Combining constitutive equation of BINGHAM Fluid with equation of motio n and energy equation for pipe flow,the velocity and the temperature profiles fo r annular pipe flow of BINGHAM fluid wer e obtained.Because of yield stress,there is a flow core in annulus.The width of the flow core is directly proportional t o yield stress and inversely proportiona l to generalized pressure gradient.The c enter line of the flow care is partial t o the inner side of annulus.The smaller the diameter ration of inner and outer p ipe is,the greater the relative departur e between the center line of flow core a nd that of annulus is.When the other con ditions are changeless,with increasing y ield stress the velocity profile becomes flatter.The velocity of flow core incre ases with decreasing the diameter ration of inner and outer pipe.Temperature var iation of the flow core is obviously lar ger than that of the inner and outer vel ocity gradient region.The temperature pr ofile in annulus becomes flatter with in creasing yield stress.