Encyclopaedia Index

### TITLE : A tube with spiral rib

BY : Dr S V Zhubrin, CHAM Ltd

DATE : November, 2000

Updated : May, 2006

FOR : Demonstration case for PHOENICS PHOENICS 3.3.1 / 3.6.2

### INTRODUCTION

Shapemaker has been used
here to create the spiral rib object and the case presented makes use of it for the
situation when the ribbed tube is cooled down by natural convection in a cylindrical
chamber.

### THE STATEMENT OF THE PROBLEM

This case deals with the free-convection flow of fluid arising in an annular cavity the
inner rib augmented tube of which has higher temperature than the outer chamber surface.

### COMPUTATIONAL DETAILS

### Conservation equations

The independent variables of the problem are the three components of cylindrical polar
coordinate system, namely X, Y and Z.

The main dependent (solved for) variables are:

- Pressure, P1
- Three velocity components, U1, V1, W1 and
- Temperature of the medium, TEM1.

### Buoyancy model

The Boussinesq approximation is used to incorporate the temperature dependence of the
density.

### THE RESULTS

The plots show the distribution of velocity and temperature within the enclosure.

Pictures are as follows :

Geometry

Velocity vectors

Temperature contours

### THE IMPLEMENTATION

All model settings have been made in VR-Editor of PHOENICS 3.6.2

The relevant Q1 file can be inspected by clicking here.

svz / jcl