Performance analysis of coaxial thermocouples for heat flux measurement of an aerodynamic model on shock tube facility

Abstract

The K, E and J-types of coaxial thermo-sensors have been used to measure surface heat flux at the nose, spatial position-1 and spatial position-2 over an aerodynamic model subjected to a homemade shock tube flow facility. The high pressure shock has been applied to the aerodynamic model for 60 ms subsequently their variation in transient temperatures have been recorded for four experimental shots. The surface heat flux has been predicted from the transient temperatures by using one-dimensional heat transfer theory in a semi-infinite solid body. The average errors have been found between four experiments for transient temperature and surface heat flux are less than ±0.2% and ±4% respectively. A two-dimensional numerical model has been developed by using commercial software Ansys to solve the high enthalpy flow facility as exists in shock tube arrangement to validate the experimental results. The accuracy found in transient temperatures and surface heat fluxes are ±0.51% and ±0.633%. These coaxial thermo-sensors will help the design and development of aerodynamic vehicles in terms of measurement of heating rate on different inclined surfaces, missile nose, hypersonic aircraft technology, gun barrel test, advanced production technology, engine measurements etc.