Abstract
An analytical method is presented for the evaluation of frictional pressure drop making use of the analogy between heat and momentum transfer for the case of two-phase flow associated with convective condensation of vapor in a horizontal tube. Experimental data of Kutateladze for in-tube condensation heat transfer are taken, which are cast in the form of an equation for j-factor as a function of the Reynolds number of the two-phase mixture. Colburn's analogy (i.e., Reynolds analogy with correction for Prandtl number) equation between j-factor and friction coefficient is used in the analysis. An expression for two-phase density of the homogeneous mixture is obtained using a momentum balance with the aid of Levy's equation for void fraction. The two-phase friction multipliers obtained in the present analysis showed good agreement with those of earlier authors in literature. To test the present approach further, it is applied taking the correlation equation of Shah for condensation heat transfer coefficient. The friction multipliers thus obtained are compared with earlier authors, and show reasonable agreement.