Patent ID: 7409875

Claim:
A method of determining velocity of a flowing fluid with the fluid being electrically conductive with finite resistivity, said method comprising the steps of: controlling the flowing fluid between an upstream and downstream location thereof to insure that a convection timescale of the flowing fluid is less than a thermal diffusion timescale of the flowing fluid between said upstream and downstream locations; coupling first and second nodes of a current-carrying circuit to the fluid at said upstream location wherein the flowing fluid passes between said first and second nodes; applying a current pulse to the current-carrying circuit wherein said current pulse travels through the flowing fluid to thereby generate a thermal feature in the flowing fluid at said upstream location, and wherein said thermal feature is convected to said downstream location; monitoring the fluid flow at said downstream location to detect a peak associated with said thermal feature so-convected; and determining velocity of the fluid flow using (i) the distance between said upstream and downstream locations, and (ii) the time between said step of applying and detection of said peak.