LAUSR

In the present work, different passive methods have been numerically investigated to improve the thermal performance in a miniature channel. The heat transfer and pressure drop of 1 vol% Al2O3–H2O nanofluid inside triangular longitudinal pin fin miniature channel and 0.5 vol% SWCNT–H2O nanofluid inside miniature channel with wavy vortex generator with different angles have been numerically investigated. The angles of wavy vortex generator have been considered to be 0°, − 60° and 60°. The nanofluid flow has been simulated by mixture two-phase model. The results show that the thermal performance of Al2O3–H2O nanofluid is increased about 40% compared to that of pure water in miniature channel, while the pressure drop is slightly changed. The overall performance has been improved by the triangular pin fin and wavy vortex generator in miniature channel. The highest value of the overall performance has been observed for Al2O3–H2O nanofluid in triangular longitudinal pin fin miniature channel; the increase rate is about 83% than that of pure water in miniature channel. Also, in all different angles of wavy vortex generators, the thermal and frictional performances have been increased by adding the SWCNT nanoparticles. But, the effect of nanoparticles on the frictional performance was negligible. Also, the heat transfer and pressure drop have been increased when the angle of the wavy vortex generator was 0°. The highest and least values of the overall performance are observed for angles of 60° and − 60°, respectively.