Infrared Spectra of Aluminum Fluorocarbon Polymer Compositions to Thermal Signature of Jet Engine
Flares are energetic materials, which can yield thermal signature that can to interfere with infrared guided missiles. Flare thermal signature should be similar to aircraft but with higher intensity; this signature depends on exothermal reaction as well as the chemical nature of combustion products. Aluminum is the most common reactive metal fuel in use in energetic systems as it can offer high heat output (32000 J/g) as well as superior chemical stability. In this study, different flare formulations based on aluminum as a fuel, fluorocarbon polymer (Teflon) as an oxidizer, and Viton as a binder (with fuel percentage from 40:70 wt%) were developed by granulation and subsequent pressing. The spectral performance of developed formulations was evaluated to the thermal signature of aircraft jet engine using (FT-MIR 2-6 μm) spectrophotometer. The thermal signature of jet engine was characterized with two characteristic peaks over α (2-3 μm) and β (3-5 μm) band; this signature was correlated to black body emission by the hot nozzle at 690°C. The developed flares offered similar thermal signature but with higher intensity. Aluminum/Teflon/Viton (ATV) flare, with 50 wt% Al, offered an increase in the intensity of α band and β by 6 and 1.5 times respectively. The developed ATV flare offered characteristic intensity ratio Æ (Iα/Iβ) (the main spectral parameter) of 0.73; this value was found to be in good accordance with literature. Quantification of infrared emitting species as well as combustion temperature was conducted using the ICT thermodynamic code. ATV flare (50 wt% Al) offered the highest percentage (78.1 wt%) of AlF the main IR emitting species as well as 12.1 wt% of C soot which is an ideal black body emitter. This is manuscript would open the route for the development of flares with tailored spectral performance.
Amir Elsaidy, Mohamed Kassem, Hesham Tantawy, Sherif Elbasuney and Gaber Zaky M