A novel thermocouple for ultra high temperature applications: Design and computational analysis

The development of high temperature sensors for accurately measuring temperature has become critical for structural health monitoring of high temperature structures viz. gas turbines, furnaces and hypersonic space vehicles. Conventional thermocouples have limitations owing to the maximum operational temperature of metallic alloys. In this perspective, it is imperative to explore new material systems which can extend the operational range of thermocouples up to 2500K temperature. Current work investigates a novel thermocouple design which employs Zirconium diboride based ultra-high temperature ceramics for providing protection to metallic thermocouple wires in oxidizing environments in heat flux as high as 2.5MW/m2 for up to 120s duration. The performance evaluation of this novel thermocouple design has been carried using Finite element based computational modelling. This demonstrates that the proposed thermocouple design has good sensitivity of 3V/K in relevant hot environment.