Numerical simulation of flow and heat transfer characteristics in helical pipe
FENG Lulu, XU Rangshu*, FENG Jianyu
Liaoning Key Laboratory of Advanced Measurement and Test Technology for Aircraft Propulsion Systems, Shenyang Aerospace University, Shenyang, Liaoning 110136, China
Abstract:Aiming at fluid flow and heat transfer characteristics in helical pipes, an experimental model of helical pipe was selected as the study object. The flow and heat transfer of water in the pipe was numerically simulated by using Fluent, based on the realizable k-ε turbulence model and thin-wall thermal resistance model along with first kind thermal boundary condition. The velocity and temperature fields in the pipe were obtained at different water flow rates. In addition, the correctness of the numerical simulation method was validated by comparison with the experimental results. With increase of Reynolds number, the core of Dean vortex in the secondary flow in the pipe expands to the wall of the pipe. The comprehensive heat transfer properties in the pipe are the best in a small curvature ratio and at Reynolds number ranged in 2 280-6 000. The correlations of convective heat transfer and pressure drop were established by using multilinear regression model based on the simulated data. It can provide a certain reference for design and optimization of helical-coiled heat exchangers.