Abstract: This invention is a flow measurement device that has high spatial (less than 1.0×1.0 mm2) and temporal resolution (greater than 10 s to 100 s kHz) to measure flow properties in unsteady and direction-reversing conditions. The present invention can have an oscillating substrate, hot wire prongs, a hot wire attached to the hot wire prong, sensor leads from the prongs to a constant temperature anemometry circuit (CTA), means for the oscillating substrate to oscillate the substrate at a frequency greater than a characteristic cycle frequency of the flow to be measured, at a frequency less than a CTA bandwidth frequency, and such that a frequency and amplitude (Aw) of oscillation are sufficiently large to be detected, and means to obtain two measurements during an oscillation cycle when the hot wire is at its maximum oscillation velocity. Alternatively, the prongs can be eliminated and a hot wire or hot film can be directly applied to the oscillating substrate.

Abstract: This invention is a flow measurement device that has high spatial (less than 1.0x1.0 mm2) and temporal resolution (greater than 10s to 100s kHz) to measure flow properties in unsteady and direction-reversing conditions. The present invention can have an oscillating substrate, hot wire prongs, a hot wire attached to the hot wire prong, sensor leads from the prongs to a constant temperature anemometry circuit (CTA), means for the oscillating substrate to oscillate the substrate at a frequency greater than a characteristic cycle frequency of the flow to be measured, at a frequency less than a CTA bandwidth frequency, and such that a frequency and amplitude (Aw) of oscillation are sufficiently large to be detected, and means to obtain two measurements during an oscillation cycle when the hot wire is at its maximum oscillation velocity. Alternatively, the prongs can be eliminated and a hot wire or hot film can be directly applied to the oscillating substrate.