Thermal performance and optimization of hyperbolic annular fins under dehumidifying operating conditions – analytical and numerical solutions

• An approximate temperature and humidity ratio relationship provides excellent results for completely wet fin case.
• Fin optimization is presented for completely wet fin.
• A numerical solution is convenient to account for actual psychrometric relationship.
• Effect of orthotropic thermal conductivity is studied using a finite element model.
• The orthotropic thermal conductivity has considerable effects on fin performance.

The thermal performance of hyperbolic profile annular fins subjected to dehumidifying operating conditions is studied. An analytical solution for completely wet fin is derived using an approximate linear temperature–humidity relationship. A numerical solution using actual psychrometric relationship for completely and partially wet operating conditions is then obtained to account for the actual temperature–humidity ratio psychrometric relationship under both partially and fully wet operating conditions. An excellent agreement is observed between analytical and numerical solutions for completely wet fin. The fin optimization is presented based on the analytical solution of completely wet fin. Finally, a finite element formulation is used for studying the two-dimensional effects of orthotropic thermal conductivity on the thermal performance of fin under partially and fully wet operating conditions.