Directional fluid flow transducer

Abstract

A fluid flow sensor apparatus for determining speed, mass flow and direction of motion relative to a fluid in which the sensor is immersed. The sensor is constructed of at least two spaced apart resistive electrical conductors which are mechanically supported to provide a degree of thermo isolation between the conductors in order to effect the determination of instantaneous fluid flow direction. A pair of the conductors is joined so that the flow around separate conductors is avoided so as to force one conductor to be a leading edge to the flow stream and the other conductor to be a trailing edge, with separate flow passing over the conductor pair. The electrical conductors can be wires or they can be metallic or resistive films which are deposited on a supporting body. The conductor is made of a material which exhibits a change in the electrical resistivity as a function of temperature. Electrical connections are provided on each end of each conductor to permit each conductor to be separately heated by its own electrical current. The paired conductors can be supported at one end so as to be cantilever in form, whereby they are joined along a major part of their length, with the lead wires for the electrical connections extending from one end of the cantilever form. The pair of electrical conductors is connected in series, and they are electrically excited so that their total series resistance is maintained constant by a feed-back operation, and the potential at the junction of the two series connected conductors can be observed to electrically change in value as a function of direction flow, and the total series output of the pair of conductors can be electrically observed to indicate fluid velocity.

Dependencies are inferred from the claim text.