By Emily M. Hunt West Texas A&M University
Temperature variations that provide valuable information about heat transfer and fluid phenomena that occur during a mechanical and chemical process stand out clearly in an infrared image. An overview is given for three different mechanical engineering projects currently using infrared imaging to describe high-speed thermal events and provide experimental data for computational models. The first project involves conducting experimental measurements and numerical simulations to investigate the effect of mist on the spray heat transfer and fluid dynamics in the cooling of a cylindrical surface heated to the nucleate boiling temperature range. Infrared imaging (FLIR A40) is used to capture the effect of the spray flow conditions on the droplets transportation process around the heated cylinder. As a comparison to laser ignition behaviors, the next study focuses on impact ignition of nano and micron scale energetic material composites. An impact tester is used to measure ignition of the energetic composites to drop-weight impact. Ignition is determined using highspeed thermal imaging (FLIR SC6000). Results show that the difference in ignition sensitivity between composites is greater with laser than with mechanical ignition and a diffusion mechanism controls mechanical ignition. The overall goal of the third project is to use infrared imaging (FLIR SC6000) to examine the initiation and propagation of heat in explosives. To achieve this goal, infrared imaging is used to accomplish map the temperature field created by heating explosive crystal to observe "hot spot" peaks in the material.