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.