Effect of using nano-encapsulated phase change material on drag coefficient and temperature in a square cylinder

In the present paper, a two-dimensional model for investigating thermal and hydrodynamic characteristics of a square cross-section cylinder with nano-encapsulated phase change material (NEPCM) as the coolant is studied. Continuity, momentum and energy equations are solved using finite volume method based on SIMPLE algorithm. Base fluid and NEPCM particles material are pure water and n-octadecane with an average diameter of ۱۰۰ nm and melting range of ۱۰ K, respectively. Coolant flow is steady and laminar, while the square cylinder emits a constant heat flux of ۲۵۰۰ W/m۲ into the fluid around it. Effects of NEPCM particles volume fraction in the range of ۰% to ۲۰% and Reynolds numbers ranging from ۵ to ۴۰ on Nusselt number, drag coefficient and local cylinder temperature are studied. Results show that utilization of NEPCM particles increases Nusselt number and decreases local cylinder temperature. These nanoparticles slightly increase drag coefficient. With enhancing Reynolds number, Nusselt number increases for both base fluid and NEPCM slurry. Additionally, it is found that local temperature of cylinder and drag coefficient are inversely related to Reynolds number

کلیدواژه ها:

square cylinder ، phase change material ، nano-encapsulated PCM ، volume fraction