Numerical study of local heat transfer in tube bundle in pulsating flow

Abstract

Forced pulsating flows enhance the heat transfer of various heat exchange equipment; however, such flows remain poorly understood. A numerical simulation was used to study how the position of a cylinder in a tube bundle affects the heat transfer during pulsating flow. The tubes of the tube bundle were arranged in an in-line order with the same relative pitch of 1.4. The Reynolds number and Prandtl number had constant values of 1500 and 4.03, respectively. The pulsating flow exhibits a reciprocating asymmetrical character. The pulsation amplitude related to the cylinder diameter was in the range from 0.1 to 0.4, and the pulsation frequency was in the range from 0.2 to 0.8 Hz. The numerical simulation results indicated that the heat transfer of the cylinder in the tube bundle was affected by the row number. With pulsating flow, the heat transfer of the cylinder in the first row had a minimum value, whereas the maximum heat transfer was observed in the last row. The effect of the position of the cylinder along the flow in the tube bundle decreases with increasing pulsation intensity. The maximum heat transfer enhancement of 51% was observed in the first row at a frequency of 0.8 Hz and amplitude of 0.4.