National Aerospace Laboratory of Science Technology Agency

Tokyo Aircraft Instrument Co., Ltd.

Asao Hanzawa

Teruomi Nakaya

Naoaki Kuwano

Seizo Suzuki

Yoshio Hayashi

Toru Iwata

Takashi Saitow

Mitsuo Usami

Seigou Nakamura

Masao Ebihara

A flight velocity vector measuring system in a wide velocity region in which an attack angle pressure coefficient C&agr; of air current, a sideslip angle pressure coefficient C&bgr; and an air current angle pressure coefficient C&ggr; are obtained from five pressure information detected by a square truncated pyramid-shape probe. The aforementioned pressure coefficients, pressure calibration coefficients with respect to a Mach number M, an attack angle &agr; and a sideslip angle &bgr; every velocity region obtained by dividing the wide velocity region into a plurality of regions stored in advance in the calculation processor, and a Mach number M, an attack angle &agr; and a sideslip angle &bgr; of unknown quantity constitute a calculation processing expression comprising a polynomial approximation to call the pressure calibration coefficients in the velocity region, and flight velocity vectors (M, &agr;, &bgr;) are calculated by the polynomial approximation.

Flight velocity vector measuring system in wide velocity region using truncated pyramid-shape probe

A flight velocity detection system using a truncated pyramid-shape multi-e Pitot probe in which an extreme end portion has a truncated pyramid-shape, a cylindrical hole is provided at the apex thereof, a total pressure tube of a smaller diameter than that of the cylindrical hole is secured at a position by a predetermined length determined by a relationship with the diameter of the cylindrical hole from the extreme end of the cylindrical hole, and groups of pressure holes comprised of a plurality of pressure holes are arranged in each of the truncated pyramid surfaces of the truncated pyramid shape. Items of pressure information detected by the probe are input into a velocity vector processor to convert them into electric signals, and signals are processed using pressure coefficients of the holes of the probe with respect to the velocity vector stored in advance in the velocity vector processor to calculate flight velocity vector (V, .alpha., .beta.) with respect to the probe axis from the pressure information and air density.

Truncated pyramid-shape multi-hole pitot probe and flight velocity

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Hachioji, Japan

Asao Hanzawa