Numerical simulation of contact condition effects on heat exchanger performance.

A numerical study has been conducted to investigate the effects of the fincollar form on the heat transfer performance of cross fin-tube heat exchangers. A triangular space is formed by two adjacent fincollars and a heat transfer tube form during the heat exchanger assembly process. The triangular space increases thermal resistance between the tube and fincollars. Increase the triangular space increases the non-contact surface area between the tube and the fincollar. The non-contact area decreases the average contact conductance between the tube and fins and therefore a decrease of heat transfer rate.