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  3. i really need help with this problem the material in...

Question: i really need help with this problem the material in...

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I really need help with this problem. The material in the chapter does not explain how to solve this. Might need to use the Buckingham Pi Theorem? I have no clue how to approach. Thanks for the help in advance!
1.6. Dip coating Various industrial processes require that a flat sheet be coated with a uniform liquid film. Dip coating is a procedure in which an immersed substrate is withdrawn through a liquid-gas interface. In the process in Fig. P1.6, in which a substrate is pulled upward at a constant velocity V, the coating achieves a uniform thickness H at a certain height above the liquid. It is desired to predict H from V and the liquid properties (u, p, and γ). Air Figure P1.6 One side of a solid sheet being withdrawn upward from v a liquid. Solid Liquid (a) Representative values are H= 0.02 to 0.2 cm, V-0.4 to 3 cm/s, μ 0.3 to 2 Pa.s.p-900 kg/m3, and y 30 mN/m. By examining the ranges of dimen- sionless groups, show that viscosity, gravity, and surface tension are all important, but inertia is not. 25
(b) A theoretical result that is applicable here is (White and Tallmadge, 1965) 0.944(r)2/3 (P1.6-1) Show that this may be rewritten as a relationship between Bo and Ca. (c) If one group is chosen now as N- (Bo/Ca)1/2- [H2g/(v)2 and Ca is the sec- ond group, show that (P1.6-2) Use this to derive explicit expressions for N for Ca → 0 and Ca → oo. How does H vary with Vin these limits?
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