Encyclopaedia Index

### TITLE : Radiative oven for heat treatment

BY : Dr S V Zhubrin, CHAM Ltd

DATE : October, 2000

FOR : Demonstration case for V3.3.3.

### INTRODUCTION

An IMMERSOL application is presented aimed at the demonstration
of the method for the 3D situation when the thermal radiation is dominant.

### THE STATEMENT OF THE PROBLEM

A 3D oven for heat-treating samples is 0.32mx0.32m in cross
section and 1.5 m long.

A radiant heater panel consists of a row of cylindrical electrical heating
elements 1 cm in diameter, 150 cm long, spaced at a 3 cm pitch, and backed
by a wall convectively cooled from outside. The panel has dimensions 30x150 cm
and is located 30 cm above a well insulated floor, which is also 30x150 cm.
The heater elements are rated at 5 kW each. The emittances of the elements and
back wall are 0.9 and 0.8, respectively.

Two pieces of metal and brick loads are placed on the asbestos sheets.

The heat transfer coefficient of the ceiling and back/front walls to the
ambient air of 300K are 20 and 10 W/m^2K, respectively. The heat transfer
from black side walls is rated at 300 W/m^2K.

The task is to calculate the distribution of temperatures and radiant heat
fluxes.

### COMPUTATIONAL DETAILS

### Conservation equations

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

The main dependent (solved for) variables are:

- Temperature of the medium, TEM1 and
- radiosity temperature T3.

### Model of radiative transfer

The IMMERSOL model is used to simulate the distribution of T3 and TEM1
within the space filled with transparent air. From the temperature fields
the radiant heat fluxes, QRX, QRY and QRZ, W/m^2, are calculated and used as
the heat sources in iterative manner.

### THE RESULTS

The plots show the distribution of temperature and directional radiant heat
flux within the oven, heater elements and loads.

Pictures are as follows :

### THE IMPLEMENTATION

All model settings have been made in VR-Editor of PHOENICS 3.3.1.

The relevant Q1 file can be inspected
by clicking here.