Numerical investigation on falling film flow and heat transfer characteristics over corrugated plates

Abstract

Falling film flow is commonly utilized in engineering applications. To explore the heat transfer process over falling film plates, the effects of structure and liquid inlet Reynolds number on flow and heat transfer characteristics are studied. The results indicated that corrugation amplitude and flow rate thicken the liquid film. As the corrugation amplitude increased, the critical inlet flow velocity for smooth flow gradually rose. The local heat transfer coefficient was great in the thin fluid film. The heat transfer performance of the optimum corrugated plate was 45%–77 % higher than that of a flat plate. An empirical correlation equation for Nusselt number was developed at Reynolds number of 149.28–398.09 and corrugation amplitude to wavelength ratio of 0.025–0.1. The deviation was less than ±21 %. These findings are significant for necessary temperature regulation in the CO2 capture packed column and also provide references for falling film equipment design and evaluation.