Investigation on Characteristics of Pressure Drop for Binary Mixture in Horizontal Micro-fin Tube

Using non-azeotropic refrigerant mixture R32/R134a as the working fluid,the experimental study on the horizontal micro-fin tubes was conducted.Several factors affecting pressure drop were analyzed,and the characteristics of flow boiling and pressure drop of the mixture in the horizontal micro-fin tubes were discussed.Based on the experimental data,the acceleration resistance was calculated according to the phase separation model,and the empirical correlations for frictional resistance were obtained.The calculation result is well consistent with the experimental data

Study on Nucleation and Growth Mechanism of Snow Crystal

Innature ,theformatio nofsnowcr ystalsisve ryintr icateinclud ingnucleation ,growth ,andaggre gation .Re search onthenucle ationand growthofsnowcr ystalsi simportan ttothesnow makingtec hnology .Thesha pesofsnow crysta lsaredete rminedbyth ecrystallatt iceofic eandthegrowt hconditions .Thecrit icalrad iusand critic alener gybarri erforthef ormationo ficenucleus weredetermi nedthr oughanalyz ingthefreeene rgychan geofhomoge neousandhet erogene ousnu cleation ,whichp rovidest heorybasi sforthestu dyofice nucleus .Therel ationsbetw eenshap esofsnow cryst alsandg rowthratesw eredefi nedtheore ticallyusi ngtherelat ionsbetween themas sgrow thrate sofsno wcrystals andwat ervap orflux