Akademik Veri Yönetim Sistemi
JOURNAL OF ENHANCED HEAT TRANSFER, cilt.14, sa.2, ss.135-146, 2007 (SCI-Expanded)
In this study, three-dimensional heat transfer enhancement was investigated numerically by using turbulence generator produced of stainless steel at three different winglet distances (w) and three different winglet angles (theta). FLUENT computer code is used for numerical calculations. Firstly, calculations were conducted for a smooth pipe and the results were compared with the widely used equations available in the literature. The results showed a good agreement and so, the numerical method was validated. For obtaining net heat transfer increase, the comparison should be made for the constant velocity value. As a result, for equal velocity values, the highest beat transfer increase was obtained by an inserted turbulator with w = 5 cm and theta = 60 degrees. The heat transfer value decreases with decreasing winglet angles. It was shown that using of turbulators inside the pipe gives an increased Nusselt number and both winglet distance (w) and winglet angle (theta) of the turbulator exert an effect on heat transfer. As calculations show, heat transfer is enhanced at different winglet distances and angles of inserts in the pipe when compared to the smooth pipe. So, this kind of inserts can be used in heat exchangers to increase heat transfer and energy saving.