SBIR-STTR Award

If the development of a vehicle capable of sustained hypersonic flight in the atmosphere at speeds above Mach 8 is to be realized, a ground-based wind tunnel with a reliable force measurement system is a necessity. However, above Mach 8, due to thermal survivability of wind-tunnel nozzle throat materials, only impulse tunnels having test times no more than several milliseconds in duration will be available for the foreseeable future. To accomplish aerodynamic force measurement in such a short time period, a non-conventional approach for the force balance design is required. Our approach is based on the interpretation of stress waves traversing the model and a suitably designed sting as has been previously demonstrated for drag-thrust measurement in shock tunnels, and recently for three-component force measurement at GASL. This stress-wave force balance appears to offer a route to a fully-metric mounting system for impulse-tunnel test articles. This proposal endeavors to build a universal force measurement system that will accept different aero-propulsion test articles, and deliver drag, lift and pitching moment measurement within the available test time of a conventional reflected shock tunnel.

Potential Commercial Applications:
Hypersonic propulsion test facilities will need increased capability to meet the growing demands of new weapons and access to space programs. The present lack of adequately instrumented wind tunnels capable of testing above Mach 8 strongly influences the vision of propulsion and space craft system designers, tending toward limiting atmospheric operation below this speed. The development of a force measurement capability for Mach 8+ wind tunnels will open the design space spawning a new era of hypersonic systems and consequently test opportunities for the NASA-HYPULSE Facility located at and operated by GASL. Further opportunities exist in the instrument resale market. Recently, GASL has been very successful designing and building instrumentation suites for other test facilities both in the US and abroad. The proposed force measurement system will be seen as extremely important by other impulse tunnel operators and sales of such units will follow.