NUMERICAL STUDY ON HEAT AND FLOW TRANSFER CHARACTERISTICS IN RECTANGULAR MINI-CHANNEL WITH S-SHAPED TURBULATOR INSERTED

The mini-channel heat exchanger has better heat and flow transfer characteristics than conventional heat exchanger. In this study, we use the S-shaped turbulator inserted, which is simple to install and inexpensive, to improve the heat exchange. The fluid-flow and heat transfer characteristics in smooth and inserted S-shaped turbulator rectangular mini-channels are simulated by numerical simulation under constant wall temperature heating in the Reynolds number 198.77-1987.67. The results of the numerical simulation show that compared with the smooth mini -channel, the pressure drop of the three rectangular mini-channels with different inserted S-shaped turbulators with radii on the horizontal axis of 1 mm, 1.5 mm, and 2 mm increase by 334.8-774.3%, 275.9-606.4%, and 234.6-500.4%. The average Nusselt numbers grow by 28.7-98.6%, 18.8-92% and 11.1-88.5%. The total thermal resistances reduce by 22.43-50.15%, 15.91-48.40%, and 10.08%-47.45%. The field coordination numbers increase by 30.36%-115.29%, 19.72-106.94%, and 19.72-104.72%. Moreover, the non-linear regression method establishes the prediction formulas of the pressure drop and average Nusselt number. In most cases, the deviation between predicted and simulated values is between & PLUSMN;4.6% and & PLUSMN;14%.