Comparative Mode Analysis for Coefficient of Thermal Expansion Testing on the TA Q400

摘要

Traditional Coefficient of Linear Thermal Expansion (CLTE) testing had been performed in our laboratory using Liquid Nitrogen (LN2) as the coolant for testing propellants and explosives in the range of-65 ℉ to 165 ℉. The rapid evaporation of LN2 required that a relatively fast heating rate of 3-5 °C/min was necessary. ATA Q400 with a mechanical cooling accessory capable of reaching -70 °C was recently procured. Comparison of CTLE by heating rates was conducted for three materials using our traditional heating rate, a proposed Joint Army Navy NASA Air Force (JANNAF) heating rate of 0.5 °C/min, and a quasi-isothermal method.