Impact of an Arc-shaped Control Plate on Flow and Heat Transfer around a Isothermally Heated Rotating Circular Cylinder

TL;DR

This study investigates how an arc-shaped control plate affects flow patterns, vortex formation, and heat transfer around a heated rotating cylinder using numerical simulations, revealing significant control over aerodynamic and thermal characteristics.

Contribution

It introduces a detailed numerical analysis of the effects of an arc-shaped control plate on flow and heat transfer around a rotating heated cylinder, highlighting the influence of plate position and rotation rate.

Findings

Vortex shedding is shifted upward by rotation.

Vortex size reduces significantly at certain plate positions.

Rotation and plate position can optimize drag, lift, and heat transfer.

Abstract

The main objective of this paper is to study the flow characteristics of a rotating, isothermally heated circular cylinder with a vertical arc-shaped control plate placed downstream. Stream function-Vorticity ($\psi-\omega$) formulation of two dimensional (2-D) Navier-Stokes (N-S) equations is considered as the governing equation and the simulations are performed for different distances of the control plate ($0.5$, $1$, $2$, $3$), rotational rates ($0.5$, $1$, $2.07$, $3.25$) at Prandtl number $0.7$ and Reynolds number $150$. The governing equations are discretized using the Higher Order Compact (HOC) scheme and the system of algebraic equations, arising from HOC discretization, is solved using the Bi-Conjugate Gradient Stabilized approach. Present computed results show that the vortex shedding plane is shifted upward from the centerline of the flow domain by the cylinder's rotational motion. The structure of the wake varies based on the plate's position. The size of vortices is greatly reduced when the control plate is set at $d/R_0=3$ and the rotational rate is very high. At greater rotational rates, the impact of varied positions of the arc-shaped control plate is very significant. The rotation of the cylinder and the location of the plate can be used to lower or enhance the values of drag and lift coefficients as well as the heat transfer from the surface of the cylinder. The maximum value of the drag coefficient, which is about $3$, is achieved for $d/R_0=2$ and $\alpha=3.25$.