Natural Convection: Concentric Cylinders Introduction

This tutorial demonstrates how to solve a natural convection problem in Simcenter STAR-CCM+.

An infinitely long cylinder of radius 1.78 cm, heated at a constant temperature of 306.3 K, is placed inside another larger cylinder of radius 4.628 cm at a lower fixed temperature of 293.7 K. These temperatures are chosen to give an even temperature distribution about a bulk temperature (Tb) of 300 K in the annulus. As the flow is expected to be symmetrical about the center-line, it is only necessary to work with half the geometry, as shown below.



Set up the model for an ideal gas with the following material properties, evaluated at bulk temperature of 300 K and pressure of 100,000 Pa.

Property Setting
Density (kg/m2) 1.1614
Dynamic viscosity (Pa-s) 1.846E-5
Kinematic viscosity (m2/s) 1.589E-5
Specific Heat (J/kg-K) 1007.0
Thermal Coefficient of Volumetric Expansion (1/K) 1/Tb (Ideal Gas) = 0.00333
Thermal Conductivity (W/m-K) 0.0263
Thermal Diffusivity (m2/s) 2.249E-5

This case repeats the experiments of Kuehn and Goldstein [416]. Set up the physics to correspond to a Rayleigh number of 2.66 X 104.