Accession Number : AD0607382

Title :   MODULATION TECHNIQUES FOR MEASUREMENTS IN LOW DENISTY HYPERSONIC WIND TUNNELS,

Corporate Author : TRAINING CENTER FOR EXPERIMENTAL AERODYNAMICS RHODE-SAINT-GENESE (BELGIUM)

Personal Author(s) : Smolderen,J. J.

Report Date : 25 SEP 1964

Pagination or Media Count : 1

Abstract : A new technique for the measurement of small forces or other low level effects has been developed at the VKIFD low density wind tunnel. Measurement of forces as low as 10 micrograms appear feasible using ferroelectric transducers in conjuction with a low level tuned amplifier system and synchronous demodulator. This performance is made possible by periodically screening the flow on the model or even chopping the full flow of the wind tunnel by means of a mechanically actuated screen. Such modulation techniques, which result in considerable noise and drift reduction because of the narrow band width of a system using synchronous demodulation are of course widely used for the measurement of low level DC signals as well as detection of weak radiation, molecular beams, biological phenomena, etc. (Author)

Descriptors :   (*AERODYNAMIC LOADING, TRANSDUCERS), (*TRANSDUCERS, AERODYNAMIC LOADING), HYPERSONIC WIND TUNNELS, WIND TUNNEL MODELS, AERODYNAMIC CHARACTERISTICS, MEASUREMENT, INSTRUMENTATION, FERROELECTRIC MATERIALS, ELECTRONIC EQUIPMENT, FLUID MECHANICS

Distribution Statement : APPROVED FOR PUBLIC RELEASE