Numerical and Experimental Investigations on Radiative Heat Flux Characteristics of an Infrared Quartz Lamp

Infrared (IR) heating is being employed in many applications for decades. Some of these applications require accurate prediction of radiative heat flux characterization of IR heating. For example, in spacecraft applications, IR lamps are employed in thermal vacuum tests in order to simulate the external radiative heat fluxes in orbit. In order to successfully simulate this environment, accurate predictions on IR fluxes have to be made. This research presents a comprehensive information on IR quartz lamps and governs the heat transfer equations of IR lamps. Based on the heat transfer equations, a method to numerically calculate the temperature of IR lamp components is described. To calculate the temperature profile of IR lamp, detailed inspection on geometrical, thermal and optical properties of the IR lamp and the environment is discussed. A thermal mathematical model (TMM) is created and introduced, in order to predict the radiative heat flux of the IR lamp by using the calculated temperature profile of the IR lamp. The TMM results were correlated and compared with an experimental investigation, in which an IR lamp and a calibrated heat flux sensor were used. Using the recorded heat flux measurements in experimental investigations, the TMM was validated for different IR lamp power inputs and for different sensor orientations. Based on the comparison of predicted TMM results and recorded heat flux values, minimum, maximum and average heat flux prediction relative errors were calculated as between 0.3 %, 6.3 % and 2.5 % respectively. Based on the calculated relative errors, it was concluded that the TMM produces accurate results for the estimation of radiative heat fluxes.