Abstract: In this paper, the Reynolds stress model is used to simulate the circumferential non-uniform heat transfer of single-phase flow in a helical pipe. The calculation is verified based on the comparison with the experimental data. It is found that the ratio of gravity acceleration to centrifugal force acceleration (?) affects the circumferential heat transfer distribution of helical pipes. The reason for this is that the changes of ? lead to the changes of the direction of resultant force of gravity and centrifugal force. It is concluded that the main factor affecting the circumferential heat transfer distribution is ?. Besides, the changing rules and the effects of geometry parameters of helical pipes, such as the ratio of gravity acceleration to centrifugal force acceleration, pitch circle diameter, pipe hydraulic diameter, and spirally ascend angle, on the circumferential heat transfer distribution are discussed.

Key words: helical pipe, single-phase heat transfer, circumferential non-uniform heat transfer, centrifugal force, computational fluid dynamics