Airspeed sensing post for determining relative velocity of a fluid and a carrier

Claim 1

An airspeed sensing post for determining the relative velocity of a fluid and a carrier, in a direction which can vary in a substantially planar circle sector defined on both sides of a mean direction, from static pressure and total pressure values, said post including a body to be fixed to the carrier, a static pressure sensing device fixed to said body and forming a first pressure signal, and a total pressure sensing device, fixed to said body, having an orifice opening in a direction substantially parallel to said mean direction and for forming a second pressure signal, said static pressure sensing device including at least one orifice made in a surface in which it opens in a direction substantially normal to said mean direction, said surface in which at least one orifice opening includes at least a part of a revolutionary surface having a revolution axis normal to the plane of said circle sector, said revolution axis intercepting or being disposed very near to said orifice, said revolutionary surface part having an angular extension at least equal to the angular extension of said circle sector, and said revolutionary surface part being disposed at least above the orifice in the flowing direction of the fluid, so that the fluid flow arriving near said orifice is always the same and the fluid flows along a surface having the same contour when the fluid flow direction varies in the circle sector.