Theoretical investigation of the mechanical non equilibrium caused by the radial temperature distribution within two phase flows

Mechanical non-equilibrium in the cross section of a two phase flow (boiling flow) has been suggested. This approach allows the explanation of the superheated thermodynamic state of the wall layer. The pressure difference can be simply calculated using the pressure of saturation corresponding to the know temperature of the heated surface. The authors gain valuable analytic equations for heat transfer DNB. It has been demostrated physically that DNB is caused by a sonic limit for the evaporation