两头扭曲缠绕管流动换热特性数值模拟OA

A numerical simulation model of two-start twisted helically wound tube is established to sim-ulate the flow and heat transfer characteristics of pro-pane working fluid in the tube under turbulent state.The influencing factors of flow and heat transfer,such as groove depth,twisted pitch and Reynolds number are analyzed,and the dimensionless empirical formulas of friction factor and Nusselt number are obtained by fitting.The relative friction coefficient of the helically wound tube increases with the increase of groove depth,especially when the twisted pitch is small,it is more pronounced.The relative Nusselt number of the helically wound tube is positively corre-lated with the groove depth,and the effect is more sig-nificant when the Reynolds number is low and the twis-ted pitch is small.Helically wound tube is suitable for low Reynolds number and small twisted pitch.