Yamuk Kesitli Kanal İçerisinde Hidrodinamik Olarak Tam Gelişmiş Isıl Olarak Gelişmekte Olan Laminer Akış ve Isı Transferinin Sayısal Olarak İncelenmesi

Yıl 2012, Cilt: 9 Sayı: 2, - , 01.04.2012

Nevzat Onur Kamil Arslan Oğuz Turgut

Öz

In this study, steady-state hydrodynamically fully developed thermally developing
three-dimensional laminar forced convection flow and heat transfer in a horizontal
smooth trapezoidal duct were numerically investigated under uniform surface temperature
condition. Numerical study was carried out for a Reynolds number range of 100 to 1000. Air (P r ∼= 0.7) was used as the heat transfer medium. A commercial CFD program Fluent
12.1 was used to carry out the numerical study. Average Nusselt numbers and average
Darcy friction factors were presented for different Reynolds numbers. Local Nusselt numbers
were plotted as a function of the distance along the duct. Velocity and temperature
contours were given as graphically at different positions along the duct. The results obtained
from this study were compared with the results of similar studies available in the
literature, and the results were found to be in good agreement. It is seen that increase in
Reynolds number causes decrease in friction factor and increase in heat transfer. Value
of the Nusselt number for hydrodynamically and thermally fully developed laminar flow
conditions in trapezoidal cross-sectioned duct was determined to be 2.95. Based on the
present numerical investigation, new engineering correlations were obtained for the heat
transfer and friction coefficient.

Anahtar Kelimeler

Trapezoidal cross-section duct, laminar forced convection, hydrodynamically fully developed thermally developing flow, Ansys Fluent 12.1.

Kaynakça

• [1] W. M. Kays and A. L. London, Compact Heat Exchangers, McGraw-Hill, New York, 1964.
• [2] S. M. Flockhart and R. S. Dhariwal, Experimental and numerical investigation into the flow characteristics of channels etched in silicon, Journal of Fluids Engineering 120 (1998), 291–295.
• [3] R. K. Shah, Laminar friction and forced convection heat transfer in ducts of arbitrary geometry, International Journal of Heat and Mass Transfer 18 (1975), 849–862.
• [4] A. Lawal and A. S. Mujumdar, Developing flow and heat transfer to power law fluids in square, trapezoidal and pentagonal ducts, International Communications in Heat and Mass Transfer 12 (1985), 23–31.
• [5] J. B. Aparecido and R. M. Cotta, Fully developed laminar flow in trapezoidal ducts, 9th Brazilian Congress of Mechanical Engineering, 1987 (IX COBEM) (1987), 25–28.
• [6] R. Sadasivam, R. M. Manglik and M. A. Jog, Fully developed forced convection through trapezoidal and hexagonal ducts, International Journal of Heat and Mass Transfer 42 (1999), 4321–4331.
• [7] J. Yuan, M. Rokni and B. Sund´en, Simulation of fully developed laminar heat and mass transfer in fuel cell ducts with different cross-sections, International Journal of Heat and Mass Transfer 44 (2001), 4047-4058.
• [8] R. K. Shah and A. L. London, Laminar Flow Forced Convection in Ducts, Academic Pres Inc., New York, 1978.
• [9] S. Kaka¸c, R. K. Shah and W. Aung, Handbook of Single-Phase Convective Heat Transfer, John Wiley and Sons, USA, 1987.
• [10] S. Kaka¸c and H. Liu, Heat Exchangers Selection, Rating, and Thermal Design, CRC Press, USA, 2002.
• [11] M. Renksizbulut and H. Niazmand, Laminar flow and heat transfer in the entrance region of trapezoidal channels with constant wall temperature, Journal of Heat Transfer 128 (2006), 63–74.
• [12] F. P. Incropera, D. P. DeWitt, T. L. Bergman and A. S. Lavine, Fundamentals of Heat and Mass Transfer, John Wiley & Sons, USA, 2007.