LAUSR

Friction factor and heat transfer characteristics of Al2O3/water nano-particle inside the twisted square duct (TSD) using water as base fluid numerically investigated. A uniform heat flux applied on the external walls. Three-dimensional (3D) analysis of steady fully developed laminar flow inside the twisted duct of square cross-section flow area is carried out for Reynolds number and nanoparticle concentration range of 600–2000 and 0.5 %–1 % using the commercially available software. Heat transfer and friction factor characteristics of fluid flowing through twisted square duct using water/Al2O3 as normal fluid are compared with the results of the straight square duct using water as working fluid. The numerical study is conducted for a uniform wall temperature case, twist ratio of 7.5, 11.5 and 16.5, for Prandtl number range of 8 to 10. One of the key outcomes of this work is up to a limiting concentration of nanoparticle in the base fluid beyond which it decreases. It is also found that the Nusselt number increases by decreasing the twist ratio (tr) and increasing the Prandtl number. However, in the case of friction factor (f), a regular decrease in friction factor is observed with increasing Reynolds number (Re).