Entropy generation in laminar jet: effect of velocity profiles at nozzle exit

Abstract

Laminar free jet flow finds wide application in industry. Although considerable research studies were carried out in the past, but the irreversibility associated with the flow field due to heat transfer and viscous dissipation needs further investigation. In the present study, laminar free jet is considered and volumetric entropy generation in the flow field is computed. The normalized entropy ratio (entropy ratio generated in one-fourth of the jet length to total entropy generation), irreversibility, and the Merit number are determined for different velocity profiles leaving the nozzle. It is found that the uniform velocity profile results in less entropy generation due to viscous dissipation as compared to its counterpart corresponding to triangular velocity profile; however, the entropy generation due to heat transfer increases for the uniform profile.