Mohammad Hemmat Esfe, Ali Akbar Abbasian Arani, Wei Mon Yan and Alireza Aghaei Pages 354 - 363 ( 10 )
Background: Due to the wide range of the mixed convection dilemma, it becomes one of the main topics of research in the last two decades. These types of fluid flow and heat transfer occur in technological and industrial applications, such as electronic cooling, crystal growth, and solar collectors, energy-saving household, double-wall thermal insulation and oil extraction. In addition, the view of nanofluid and convection inside an enclosure and considering its complex shape, make it much more significant in these applications which motivate us to consider the present type of problem.Method: The finite volume method and the SIMPLER algorithm are employed to solve the governing mass, momentum, and energy equations. The first step of discretizing the governing equations is to generate a finite difference mesh in the computational domain. A control volume is used around each node of the mesh afterwards. The governing equations are then integrated over each control volume. The diffusion terms are replaced using a second-order central difference scheme; while, a hybrid scheme is employed for the convective terms to obtain stable solutions for convectiondominated cases. An under relaxation scheme is adopted to obtain the converged solutions. Results: Results show that for all inclination angles at various aspect ratios ranging from 0.15 to 0.5, with increasing solid nanoparticles volume fraction up to 0.015, the average Nusselt number enhances and then decreases. In these aspect ratios, for all solid nanoparticles volume fractions, the average Nusselt number at inclination angle equal to 90° is greater than it at the other. Furthermore, with increasing inclination angle from 0 to 90°, the maximum enhancement of average Nusselt number is 39.8% which occurs at nanoparticles volume fraction of 0.008 and aspect ratio of 0.75. Conclusion: At low solid volume fraction (φ=0.002), there is not a distinct differences in the temperature and streamline counters of nanofluid compared to those of the base fluid. 3. In addition, with increasing inclination angle from 0 to 90°, the maximum enhancement of average Nusselt number is 39.8% which occurs at volume fraction of 0.008 and aspect ratio of 0.75.
Cavity, inclination angle, mixed convection, nanofluid, Richardson number.
Department of Mechanical Engineering, Khomeinishahr Branch, Islamic Azad University, Isfahan, Department of Mechanical Engineering, University of Kashan, Kashan, Department of Energy and Refrigerating Air-Conditioning Engineering, National Taipei University of Technology, Taipei 10608, Young Researchers and Elite Club, Arak Branch, Islamic Azad University, Arak