4. Conclusion

In many common cases, to a first approximation, hydrodynamic effects and temperature variations at the interface can be neglected. The isoviscous hydrostatic model developed in this article can be applied. It leads to the analytical formulation of the main characteristic quantities. We have deduced the following main conclusions.

If the thickness decreases in the direction of flow, when (p _e – p _i ) (h _e – h _i ) > 0 :

• $F_{of}>\frac{\pi \left(R_e^2-R_1^2\right)\left(p_e+p_i\right)}{2}\text{et }{p}_m>\frac{p_e+p_i}{2}$...