High Heating Rate Electrical Discharge Calorimeter Calibration System

In answer to the need for an increased heat-flux calibration capability, Streamline Automation (SA) proposes a novel calorimeter calibration system including a data reduction methodology and its implementation and demonstration in a high heat-flux calibration unit, powered by an electrical discharge. The new calibration system: enables calibration at heat flux levels specific to high-enthalpy hypersonic flows, returns all the necessary information required to recover the classic step response of the calorimeter, and features a built-in means for correcting gauge output due to a zero intrinsic integrated energy deficiency. These characteristic make possible operation at a fraction of total heat flux required by classical step response calibration systems and help preserve calorimeter integrity during the calibration process. In Phase I SA has demonstrated the feasibility of the concept and has performed the calibration of a null point calorimeter. Phase II activities will include: the design and fabrication of the calibration system for flux levels up to 30kW/cm2 and test duration of up to half a second, a full system characterization, and system optimization for enhanced lifetime. At the conclusion of Phase II SA will deliver and demonstrate a fully featured system to the Air Force. BENEFIT: Hypersonic transport vehicles powered by air-breathing scramjet engines are beginning to come into focus as the quick-response space launchers and super-swift, far-ranging missiles of the future. Future development programs will require unique ground testing capabilities, such as supersonic and hypersonic wind tunnels, and sophisticated instrumentation to provide flow and thermodynamic data. Currently, the calorimeter calibration systems available to the DOD do not provide heat flux levels as high as those the calorimeters experience during testing in arc-jet heated facilities. The proposed calorimeter calibration system will enable calibration to be performed in an environment more closely approximating the operational environment (e.g. hypersonic flight, reentry etc.), thus providing a greater degree of confidence in the measured data during testing, and improving test operations. Commercially, a high heat flux calorimeter calibration system would benefit the gas turbine engine manufacturing industry, arc-jet heated, and gas-fired furnace facilities as well as organizations such as NASA, ESA and other propulsion oriented research institutions.