Surface Temperature Measurements of Burning Solid Propellants Using Phosphor Thermography

In recent years, phosphor thermography has received increased attention as an alternative to other common temperature measurement techniques (e.g., thermocouples, pyrometry). This technique has been successfully used for surface temperature measurements on coated surfaces (e.g., turbine blades, furnace walls) and, in some cases, mixed with a reacting material. However, this technique has yet to be used for measuring the surface temperature of burning energetic materials (e.g., propellants, explosives). Adapting this technique to the study of energetic materials would enable temporally and spatially resolved surface temperature measurements that also lack some of the shortcomings of conventional methods. This work investigates the feasibility of using phosphor thermography to measure the surface temperature of burning nitrocellulose, an energetic material used extensively in single-, double-, and triple-base propellant formulations. Using phosphor thermography, two-dimensional time-resolved surface temperature measurements were obtained across the surface of a burning nitrocellulose pellet. The average surface temperatures measured with this approach (T=534 K) were in good agreement with previously published measurements for nitrocellulose obtained with embedded thermocouples (T=523 K). This work demonstrates the viability of using phosphor thermography for measuring the surface temperature of burning solid propellants as well as other types of energetic material compositions.