The Study Of The Super-hydrophobic Surface And Slip Flow In Microchannel

With the research development of flow in the micro-scale areas, People find the slip flow phenomenon more and more in the micro-scale areas. The no slip boundary condition of macro areas can no longer explain these phenomenon. So the slip boundary condition comes into being. The study development of super-hydrophobic surface offers the best material basis for the study on the slip flow phenomenon.First,this paper reviews and sums up the basic knowledge and the current situation of super-hydrophobic surface and outlooks the development orientation of the preparation of super-hydrophobic surface;It gives the slip basic concepts,the affect factors on the slip flow and the physical mechanism of slip flow. It makes the detailed summary on the main achievements of experimental study and numerical simulation study in the past two years .Second,this paper introduces the preparation method of super-hydrophobic surface used in our experimental process,and highlight preparation method of the super-hydrophobic surface used by the electroplating fluoride syntheticism method the author invented. The result shows,the contact angle of super hydrophobic surface prepared by the electroplating fluoride syntheticism method is more than 120°,and the largest contact angle is 162.3°.So the electroplating fluoride syntheticism method has the same effects with the chemical dislocation etching method .It also makes the hydrophobic -lasting experiment of super-hydrophobic surface made respectively by the chemical dislocation etching method and the electroplating fluoride syntheticism method. The result shows that the surface made by the electroplating fluoride syntheticism method has the longer hydrophobic-lasting time .So it concludes that the electroplating fluoride syntheticism method surpasses the chemical dislocation etching method.Third,this paper uses three kinds super-hydrophobic surfaces of different CA to make the single-side slip experiment .At the same time, It makes the double-side slip experiment. The result shows that at the same condition, the pressure drop of double side silp is lower than that of single side slip by 40.3%.The dimensionless pressure drop ratio of double side slip is 0.464,while that of single side slip is only 0.148.The slip length of double -side slip is as 2.54times as that of single- side slip .The slip velocity of double-side slip is 2.32 times as that of single side slip. It also makes the analysis the affect of temperature,contact angle and the height of micro-channel on the slip .Finally, It has computed that the slip flow in microchannels with superhydrophobic surface by numerical simulation with directly being given the wall slip velocity to simulate the slip boundary condition using Fluent software. Given the wall slip velocity,It makes the analysis that how the dimensionless pressure drop ratio and slip length varies with fluid velocity;Given the slip velocity and fluid velocity of experiment,it make the contrast of the theoreticalΔP with experimentalΔP .