Numerical Simulation of fluidic aspects and heat transfer for geometry modification in an elliptical cylinder bundle

Abstract

In this paper, flow field separation due to an adverse pressure gradient around rotating elliptical cylinders in a two-dimensional laminar flow inside a rectangular-shaped channel is investigated. To do so, the effects of the cylinder’s rotation and aspect ratio are considered to examine the transient heat transfer, drag coefficient, velocity field, and vortex shedding. According to the results, it was reported that the maximum transient heat transfer occurred at Cylinder number 2, and the least heat transfer was related to Cylinder number 4. Thus, transient heat transfer increased by 33% by increasing the aspect ratio. The results show that the arrangement of elliptical cylinders inside the channel has caused the minimum pressure drop in the flow direction. The vortex generation frequency is also reported to be the least for the first cylinder located along the channel, and by moving from the channel inlet, the magnitude of these vortices becomes larger. The maximum drag force is imposed on Cylinder number 5 (the last cylinder), while, contrary to expectations, the least drag force is applied to Cylinder number 2. Statistically, by increasing the rotation angle from Cylinder number 2 to Cylinder number 5, the skin friction coefficient increases by 107%, denoting the increase in drag force. It is also reported that the vortex distribution is symmetrical around both sides of the cylinders.