Semianalytic method for heat transfer calculation in the liquid film under conditions of a constant heat flux on the wall

For calculating the heat transfer in the free-falling liquid film, a semianalytic method is offered in which the temperature field in the liquid is presented as a series of basis functions which satisfies boundary conditions. The proposed method is demonstrated by the example of the problem regarding the film heating under conditions of the constant heat flux on the wall taking into account the heat transfer on the interfacial surface. The analytical solution is derived for the thermal initial section, on which the liquid heating occurs in a thin layer near the wall. Calculations using the proposed method are well agreed with the numerical solution obtained by the finite-difference method and with experimental data.