NUMERICAL SIMULATION AND OPTIMIZATION OF CONVECTIVE HEAT TRANSFER AND PRESSURE DROP IN CORRUGATED TUBES

The fluid flow and heat transfer inside corrugated tubes have been studied numerically using the JL (Jones and Lauder, 1973) low-Re k-epsilon turbulence model. The simulated results agree well with the experimental results. Numerical calculation results widen the Reynolds number range of the fluid flow and heat transfer correlation for corrugated tubes. It is found that the tendency of the friction coefficient to variation with the Reynolds number for the corrugated tubes follows the exponential law in a wider Reynolds number range. Effects of different ripple heights and ripple spacings on fluid flow and heat transfer are investigated, and comprehensive evaluation is made for the performance of the model parameters. The results show that the effects of ripple height on flow and heat transfer inside corrugated tubes are more significant than those of ripple spacing. The optimized calculation and analysis are performed; it is found that the enhancement of heat transfer in corrugated tubes could be realized only at high Reynolds numbers, there exists an optimal Reynolds number range (10,000 < Re < 12,000) where the heat transfer factors of eta reach the peak, hence, the heat transfer and fluid flow in corrugated tubes are optimal.