CFD study of heat transfer for oscillating flow in helically coiled tube heat-exchanger

• The correlation for the calculations of the average Nussel number and average friction factor for the oscillating flow in helically coiled tube heat-exchanger were proposed.
• The uniform design method in the heat transfer area and verified the feasibility of this method for multi-factors heat transfer problems.
• The field synergy principle was used to explain the heat transfer enhancement in oscillating flow in helically coiled tube heat-exchanger.

The heat transfer and pressure drop for oscillating flow in helically coiled tube heat-exchanger were numerically investigated based on the Navier–Stokes equations. The correlation of the average Nussel number and average friction factor were proposed considering the frequency and the inlet velocity. The oscillating flow heat transfer problems are influenced by many factors. Hence we need an easy way to reduce the numbers of simulation or experiment. Therefore, the method of uniform design was adopted and the feasibility of this method was verified. The field synergy principle was used to explain the heat transfer enhancement of oscillating flow in helically coiled tube heat-exchanger. The result shows that the smaller the volume average field synergy angle in the helically coiled tube, the better the rate of heat transfer.