Thermal Model of an IR-Radiator and Calculation of the Radiation Field 2001-01-2243
A thermal model of an IR-radiator with 1000 W nominal power and about 300 mm length is developed. Using the thermal software ESARAD and ESATAN the radiation field of one or an arrangement of a set of IR radiators is calculated quantitatively. This thermal model of the IR radiator arrangement can be integrated as part of the thermal model of the test article or the test set-up. Defined test runs can be simulated and the thermal behavior can be predicted.
The theoretically defined radiation field of a volume of 2m x 2m x1m was compared with a measured field of an IR radiator. There is a good agreement between the calculated and the measured values. Differences are in the range of 1% to 2.5% for the standard deviation.
The 3-dimensional radiation field is stored in equidistant steps in a matrix. This matrix is the basis of a superpositioning program which allows to calculate the radiation field of defined fields of IR radiators. The irradiance distribution of defined test planes can be predicted in absolute or relative values. For each IR radiator the origin co-ordinates, the direction of the filament and the direction of the reflector must be defined.
Examples for IR radiator arrangements and resulting irradiance distribution in the target plane are presented. An optimization for the arrangement of the IR radiators in a plane for illuminating plane surfaces of test articles, for example solar panels, is performed. The best results are obtained if the distance of the IR radiators in filament direction is 30 mm to 50 mm and perpendicular to the filament the rows are arranged in a distance of 250 mm to 300 mm.
