NUMERICAL INVESTIGATION OF GENERALIZED CORRELATIONS FOR TURBULENT FLOW PRESSURE DROP AND HEAT TRANSFER APPLIED IN HELICALLY COILED TUBE SYSTEMS

摘要

A numerical analysis using a CFD package (Fluent v5.5) has been employed to investigate the turbulent pressure drop and heat transfer characteristics in the helically coiled tube system. The validity of using the techniques for creating coiled tube geometry and the corresponding volume mesh developed in this work is verified by explicitly comparing the numerically calculated results with those obtained from the experiments and correlations related to the straight and toroidal tubes. The authors' previous work includes the collection and summary of the general and application-specific published research and correlations. The information describing the pressure drop and heat transfer phenomena related to turbulent forced convection were combined and re-expressed into more generalized correlations using multiple linear regression techniques. In this paper, a numerical research effort using a commercial CFD package has been employed to reassess the actual phenomena with those predicted by the previously developed generalized correlations. The numerically predicted pressure drop and heat transfer coefficients at various Reynolds numbers are about 5-10% lower than those obtained by using existing generalized correlations. For purposes of engineering calculations an error level of 15% or less is appropriate. The level of accuracy of the CFD modeling technique developed in this work is justified to investigate thermal-fluid phenomena in a coiled tube system.