Thermal performance of a vertical double-passage channel separated by a flexible thin sheet.

All studies regarding the double passages channel use a rigid baffle to separate the two passages. In the current paper, we use a flexible separator and inspected its role in enhancing the performance of the heat transfer. The cold fluid is forced upward in the channel which is heated isothermally by different temperatures on its walls. A flexible sheet is fixed from its two ends and equally separate the channel to two passages. The problem is investigated numerically using the finite element method coupled with the arbitrary Lagrangian-Eulerian approach. The problem is casted in dimensionless form and several pertained parameters have been inspected, like Reynolds number in each passage, elasticity of the separating sheet and the temperature ratio of the channel walls. Results are promising where it is found that the enhancement of heat transfer is possible passively in either passage with the aid of using a flexible separator rather than rigid separator. A 6% enhancement in the Nusselt number of the left passage, which comprises the higher temperature, is obtained by making the separator flexible. The flexible sheet is found to increase the pressure drop to 200% in some cases which leading to decline the thermal performance criterion to lower than unity. However, the thermal performance criterion TEC was feasible in the right passage which subjects to lower temperature. • A monolithic finite element approach using high-order schemes in space and time is utilized. • Heat transfer enhancement is possible passively in a passage with the aid flexible separator rather than rigid separator. • A 6% enhancement in the Nusselt number of the left passage is obtained by making the separator flexible. • The flexible sheet increases the pressure drop to 200% in some cases leading to decline the thermal performance criterion. • Thermal performance criterion TEC was feasible in the right passage which subjects to lower temperature. [ABSTRACT FROM AUTHOR]