(11.2.1)--6.2TheAdditionalPressureoftheCur.pdf

The Additional Pressure of the Curved Liquid Surface The surface tension causes the pressure difference between the inside and outside of the liquid surface which is called as the additional pressure of the curved liquid surface.1.The Additional Pressure of the Spherical Liquid Surface Given a spherical droplet with the radius of R,spherical cone with plane center angle of 2j can be taken out from the droplets.Vertical component:Its resultant force:When a spherical surfaces interior and its exterior reach mechanical equilibrium,the pressure inside the sphere is always higher than outside by 2/R.1dsindsin2fflrjj1ddsind sinffljj22/frR2/2/pfrR附l dfd2df1dfOrCjRS what can be proved is that such a surface will generate the additional pressure in the downward direction.-Laplace FormulaFor a spherical liquid surface,R1 meets R2 in the formula,and P equals 2/R.2.Pressure difference between inside and outside of any curved liquid level Consideration will be taken into any small surface,which includes taking a point O randomly on the surface,drawing the cross sections P1 and P2 perpendicular to each other,and obtaining the circular arc A1B1 and A2B2 by the intersections of the cross sections and the curved liquid level.Suppose that the curvature center of A1B1 and A2B2 are C1 and C2 respectively,so the corresponding radius of curvature is R1 and R2 respectively.1211()pRR附Thanks!