Wings shape effect on behavior of hybrid nanofluid in a vortex generator channel

Thermal and flow characteristics of hybrid nanofluid inside a vortex-generator channel with different wing shapes, is numerically investigated. Three wing shapes, including rectangular, triangle, and trapezoid, are considered and tested. The geometrical configuration considered in this work is representative of a channel with three wings in each row; one mounted to the top plate and the other ones mounted to the bottom plate and this trend changes between the plates alternately. The MgO-MWCNT (50:50) suspended in the base fluid of ethylene glycol with volume fractions of 0.1%, 0.2%, 0.4%, and 0.6% as working fluid. A constant surface temperature is assumed to be the thermal condition for the upper and lower walls. The effects of volume fraction of the nanoparticles and type of wings in the Reynolds number range of 200-1600, are examined and compared using the heat transfer coefficient, pressure drop and performance evaluation criterion (PEC) parameters. While the channel with rectangular wings has the greater values of the heat transfer coefficient, the results slow that the channel with trapezoid and triangle wings at the same volume fraction, have the higher values of PEC due to lower pressure drop. Also the result reporting indicates that the maximum value of PEC is 1.22 for trapezoid wings at 0.6 vol.% and at the minimum Reynolds number.

Keywords:

heat transfer coefficient , hybrid nanofluid , pressure drop , vortex generators , wings shape