Fluid velocity measurement instrument

Claim 1

A method of determining time-resolved measurements of magnitude and vector of velocity in laminar and turbulent fluid flows, said method comprising the steps of: forming a composite gauge by mounting a skin friction sensor element on a smooth surface of an electrically insulated flat plate of low thermal conductivity with bevelled edge, and placing an assortment of thermal indicators around it being within the thermal field of influence if located downstream of the thermal wake of the heated skin friction element, said elements being flush with said surface, connecting said gauge to a bridge circuit having means connected thereto to maintain the temperature or current of the skin friction element, connecting said gauge additionally to electronics having means connected thereto to convert temperature changes of thermal indicators adjacent to the skin friction element into voltage signals and to monitor these signals, mounting said gauge in a calibration device having known flow, temperature, fluid characteristics, and controlled values of velocity, relating said voltage outputs to known values of velocity, direction, and fluid composition in said calibration facility, and obtaining calibration curves which relate magnitude of the flow of selected fluids to the voltage output of the anemometer, direction of the flow to the voltage output of the thermal indicator electronics, and volume fractions of heterogeneous fluid mixtures to the voltage output of the anemometer (where applicable), removing said gauge from said calibration facility, mounting said gauge in a fluid flow to be tested with the leading edge facing the flow, either at a fixed location or moving relative to the fluid flow in a known path and time pattern, providing fluid flow relative to the gauge, measuring flow magnitude and direction of flow with said calibrated gauge, and volume fractions of co-existing constituents of heterogeneous mixtures (where applicable).

Claim 2

A method of determining time-resolved measurements of magnitude and vector of velocity in laminar and turbulent fluid flows, said method comprising the steps of: forming a composite gauge by mounting a skin friction sensor element on a smooth surface of an electrically insulated flat plate of low thermal conductivity with bevelled edge, and placing an assortment of thermal indicators around it being within the thermal field of influence if located downstream of the thermal wake of the heated skin friction element, said elements being flush with said surface, connecting said gauge to a bridge circuit having means connected thereto to maintain the temperature or current of the skin friction element, connecting said gauge additionally to electronics having means connected thereto to convert temperature changes of thermal indicators adjacent to the skin friction element into voltage signals and to monitor these signals, mounting said gauge in a calibration device having known flow, temperature, fluid characteristics, and controlled values of velocity, relating said voltage outputs to known values of velocity, direction, and fluid composition in said calibration facility, and obtaining calibration curves which relate magnitude of the flow of selected fluids to the voltage output of the anemometer, direction of the flow to the voltage output of the thermal indicator electronics, and volume fractions of heterogeneous fluid mixtures to the voltage output of the anemometer (where applicable), removing said gauge from said calibration facility, mounting said gauge in a fluid flow to be tested with the leading edge facing the flow, either at a fixed location or moving relative to the fluid flow in a known path and time pattern, providing fluid flow relative to the gauge, measuring flow magnitude and direction of flow with said calibrated gauge, and volume fractions of co-existing constituents of heterogeneous mixtures (where applicable).