Heat and mass transfer from moist air flowing inside cold horizontal circular duct : I-theoretical study

Abstract EN

Heat and mass transfer from moist air flowing inside cold horizontal circular duct is investigated theoretically.

In the present theoretical model, the flow of air inside the cold horizontal circular duct is assumed to be laminar and steady in cylindrical coordinates.

The governing equations are the continuity, momentum, energy and concentration equations.

These governing equations are put in the dimensionless form.

By introducing new proper independent and dependent variables, the governing equations are transformed to a set of dimensionless differential equations.

A computer program in FORTRAN language is developed to solve this set of equations to determine the distribution of the dimensionless velocity, temperature and concentration.

Also, local values of Nusselt and Sherwood numbers for different values of process parameters are calculated.

These parameters are presented by the following dimensionless physical quantities; Prandtl, Schmidt, and Reynolds numbers.

The present results show that, the average values of Nusselt and Sherwood numbers increase with increasing Reynolds number.

Nusselt number increases with increasing Prandtl number.

Also, Sherwood number increases with increasing Schmidt number.

Comparison between the obtained theoretical results and the previous experimental works show good agreement.