Physical and mathematic models of fluid flow and heat transfer in helically coiled tube are established

and numerical simulations of the turbulent heat transfer in helically coiled tube are performed under the uniform and non-uniform heat flux boundary conditions. The results show that

when the same heating power is exerted to the helically coiled tube surface

the turbulent heat transfer coefficient of the uniform heat flux boundary is higher than that with non-uniform heat flux boundary

and the fields synergy angle of the uniform heat flux boundary is less than that with non-uniform heat flux boundary. Meanwhile

the turbulent heat transfer coefficient of small curvature is higher with the same Dean number under non-uniform heat flux boundary while the fields synergy angle is smaller. With the increase of the tube diameter

heat transfer coefficient in helically-coiled tube declines while the fields synergy angle raises.