Thermal modelling of integrated heat exchangers with alternating ribs

The author presents a study of the flow and thermal fields encountered in heat exchangers with alternating ribs on both walls. A numerical study is conducted to solve a laminar conjugate heat transfer problem. Velocity fields were solved assuming periodic boundary conditions. The ribs and the base were assumed to have finite conductivity. The effects of the flow Reynolds number, fin height, and fin pitch on the flow and thermal fields are examined. Results of streamline contours and local heat transfer coefficients are presented. Averaged Nusselt numbers and pressure drop were plotted to analyze the effects of the governing parameters. The penalty of increasing heat transfer by inserting the ribs is the increase of the pressure drop. Water is used as the fluid and the flow is assumed to be steady, incompressible, and two-dimensional. The governing equations are solved by a finite difference code based on the SIMPLE scheme. Convergence and accuracy of the results are discussed