STUDI NUMERIK 2-D PENGARUH FREE STREAM TURBULENCE DAN MODIFIKASI TURBULENCE VISCOSITY TERHADAP PERPINDAHAN PANAS ALIRAN CROSSFLOW PADA TUBES ARRAY ALIGNED DAN STAGGERED

Abstract

The heat transfer in single cylinder and tube array is the basis of the concept that practical applications are widely used in the industrial world, such as determining the tube array design aligned or staggered on heat exchangers. The flow regimes characteristic of crossflow in the tube array is greatly influenced by the value of Reynolds number which is marked by the occurrence of stagnation point phenomenon, shear layer separation and wake formation, while the heat transfer process is influenced by Prandtl number. The heat transfer value is indicated by the average Nusselt number (Nuave) and heat transfer rate (q) parameters. This research uses numerical method 2-D RANS (standard k-e, realizable k-e, and k-ω SST turbulence model) by varying the value of free stream turbulence with the value of turbulent intensity (Tu) and modifying turbulent viscosity by way of interpreting UDF (user define function). Based on the results of the research it is known that Tu has an effect on Nuave value, heat transfer rate (q) and staggered tube arrangement is better in case of increase of heat transfer when compared with aligned tube arrangement. Nuave and q staggered tubes array rise respectively for Nuave by 2.9 % to 16.8 % and q of 10.35 % to 10.52 %.