An Optimization Approach to Thermodynamic Limitation on Convective Mass Transfer Enhancement

An optimization method to find the thermodynamic limitation on convective mass transfer for fixed viscous dissipation is developed. The method applies the principle of extremum entropy generation in the mass transfer problem. The mass transfer-induced entropy generation in the fluid flow is defined as the criterion. By maximization or minimization of the criterion under a constraint of fixed viscous dissipation, a velocity field and associate body force field can be obtained, which can enhance the mass transfer process to the thermodynamic limitation. By applying the optimization method, the dependence of the maximum extent of convective mass transfer enhancement on the viscous dissipation can be found. Such a limitation for mass transfer is shown to be useful in setting a target for mass transfer enhancement in practical applications. The analysis is illustrated by three examples.