@article { author = {}, title = {NUMERICAL INVESTIGATION OF LAMINAR FLOW AND HEAT TRANSFER IN HEXAGONAL DUCTS UNDER ISOTHERMAL AND CONSTANT HEAT FLUX BOUNDARY CONDITIONS}, journal = {Iranian Journal of Science and Technology Transactions of Mechanical Engineering}, volume = {38}, number = {M1}, pages = {45-56}, year = {2014}, publisher = {Shiraz University}, issn = {2228-6187}, eissn = {}, doi = {10.22099/ijstm.2014.1926}, abstract = {Three-dimensional laminar flow and heat transfer characteristics in smooth hexagonalducts with equal sides have been numerically investigated in the Reynolds number range from 300to 2000. The numerical solutions are obtained for both axially and peripherally constant walltemperature (T) and heat flux (H2) thermal boundary conditions for five different values of theduct angle ( = 30, 45, 60, 75, and 90o). Local Fanning friction factor and Nusselt number areobtained along the duct. Hydrodynamic and thermal entrance lengths have been determined. Theaccuracy of the results obtained in this study is verified by comparing the results with thoseavailable in the literature. Results show that duct geometry plays an important role on both flowand heat transfer characteristics. It is seen that the thermal entrance length for H2 boundarycondition is greater than that for T boundary condition. Minimum hydrodynamic and thermalentrance lengths are obtained for  = 60o, regular duct. New correlations, important for the designof thermal equipment, are presented for the hydrodynamic and thermal entrance lengths, frictionfactor, and Nusselt number for 30o    90o and 300  Re  2000.}, keywords = {Laminar flow,heat transfer,internal flow,noncircular duct}, url = {https://ijstm.shirazu.ac.ir/article_1926.html}, eprint = {https://ijstm.shirazu.ac.ir/article_1926_b471b33108e32632c2d20505b8a27b86.pdf} }