Rosemount Inc.

The B. F. Goodrich Company

Rosemount Aerospace Limited

Floyd W Hagen

Richard V DeLeo

Pennelle J Trongard

Gregg A Hohenstein

John Albert Severson

Richard V De Leo

An air data sensing probe adapted for mounting to an aerodynamically-shaped airfoil or strut attached to an air vehicle. An inlet port located near the leading edge of the strut admits fluid, to a first cavity and then, in turn, to a second cavity, so that the total temperature of the fluid may be measured and a signal related thereto conveyed to suitable flight control gear. A first exhaust port located generally opposite the inlet port allows entrained particles to exit the probe and boundary layer fluid evacuation apertures formed through the strut across the interface between the two cavities permit only a substantially particle-free core sample of fluid on the temperature sensing element. The secondary cavity couples to the primary cavity at an angle so that inertial separation of entrained particles results. In a second embodiment, the air data sensing probe connects to a barrel-shaped probe head so that multiple parameters related to the fluid can be measured, such as total pressure, Pt, static pressure, Ps, and total temperature, Tt, of a fluid flowing relative to the air vehicle as well as angle-of-attack (AOA) of the air vehicle relative to the fluid.

Integral airfoil total temperature sensor

An aerodynamic air data sensing probe adapted for mounting to an air vehicle and capable of generating signals related to a fluid flowing relative to the air vehicle. A fluid inlet positioned on a first end of the strut faces generally transverse to the fluid flow selectively admits fluid to an internal strut cavity due to a pressure differential thereacross. In operation, the pressure differential forms between the first end surface of the aerodynamically-shaped, forward-inclined strut and probe exhaust ports. A temperature sensing element disposed in the internal strut cavity registers the temperature of the fluid and the sensed fluid is expelled from the internal strut cavity through the exhaust ports. In another embodiment, a barrel-shaped probe head adapted to sense fluid pressure connects to a portion of the leading edge of the strut to form an aerodynamic multifunction air data sensing probe.

Multifunctional air data sensing probes

An air data sensing system utilizes a plurality of probes, each probe having three pressure sensing ports, and each assembled with a sensor package that minimizes the need for corrections due to temperature or other variations in ambient conditions. The system is mounted on an air vehicle using two or three sets of right and left pairs of probes. The probes of each set are vertically spaced from the probes of the other sets. The probes are made light weight and small. In the arrangement shown the probes provide triple redundancy and because of the orientation on the air vehicle provide all needed pressure and angle information, including the angle of sideslip.

Three pressure pseudo -.DELTA.-P sensor for use with three pressure air

A deployable probe has pressure ports positioned radially around a longitudinal probe axis. The probe mounts within a pressure chamber such that it can reciprocate from a retracted position where the pressure ports are contained within the pressure chamber for measuring static pressure to a deployed position where air flows generally orthogonal to the longitudinal axis of the probe and into the pressure ports such that differential pressures in oppositely facing pressure ports can be sensed for measuring relative flow magnitude and flow angles.

Deployable probe combined with flush static port

An apparatus detects an air turbulence and wind shear encountered by an air vehicle having an accelerometer sensing air vehicle vertical acceleration. The apparatus includes a pressure sensor having a pressure sensing port for sensing a pressure parameter of a local air flow which changes with changes in the local airflow turbulence, and a fast time constant pressure transducer coupled to the pressure port for generating a transducer signal representative of the parameter. Differentiating means calculates a time derivative of the transducer signal and provides a turbulence signal representative of the time derivative. Subtracter means provides the difference between the turbulence signal and a vertical acceleration signal from the accelerometer, to provide a wind shear indicating signal indicative of an increase in air turbulence. The apparatus also preferably includes a second differentiating means for calculating a time derivative of the wind shear indicating signal and provides a turbulence severity signal which when above a selected level indicates that corrective control action should be taken.

Air turbulence and wind shear sensor

An angle of attack sensor is provided with ports for sensing flow angles in desired planes based upon differential pressure at the ports when a longitudinal or reference axis of the sensor changes relative to the flow stream. Impact pressure is also measured with the same probe, or with a separate probe, and the angle of attack is calculated by subtracting the pressures at the angle sensitive ports, and dividing by the measured impact pressure (q.sub.cm). At higher angles of attack, the denominator q.sub.cm approaches and passes through zero. When this quantity, q.sub.cm, approaches zero, the angle of attack signal becomes undefined. The problems encountered as q.sub.cm approaches zero has been a limitation of useful angle of attack range of angle of attack sensors for many years. It has been discovered that if the angle of attack ratio, where q.sub.cm is the denominator, is inverted at some point when the denominator q.sub.cm approaches zero, the useable range of indication of angle of attack can be greatly extended. The present invention provides apparatus and method for inverting the ratio at selected values of q.sub.cm.

Angle of attack sensor using inverted ratio of pressure differentials

A preassembled air data sensor probe and air data transducer assembly has permanently connected flexible tubing coupling the air data transducer fittings and the sensor fittings. The flexible tubing permits the air data sensor and air data transducer to be installed into an air vehicle after having been preassembled and pretested for leaks at the factory. The permanently attached assembly avoids the need for calibration or pressure checks after installation on the aircraft. The preassembled flexible tubing permits manipulation of the transducer to mount it into the proper location even in tight quarters. The flexible tubing can have a section that acts as a drain trap for accumulating ingested water.

Preassembled air data sensor and transducer

A water separating device for a pressure measurement such as static, pitot measurement system provides a plurality of ports therethrough such that water, snow and ice from atmospheric air is substantially removed therefrom so that desired parameters such as temperature or pressure can be measured. Separation of water, snow and ice as disclosed eliminates additional chambers for collecting same and eliminates drain systems and drain valves to eliminate same from the measurement system. Since sensors are not exposed to moisture, sensor dependability and longevity is enhanced.

Water separator for air data sensor

An air data sensor comprising an elongated probe having a standard, sharped edge, orifice pitot port or opening, and a tapered leading end that is elongated with respect to its lateral dimensions along the longitudinal axis of the probe. The leading end portion blends into the main portion of the probe at a desired relatively short distance downstream from the pitot port. The probe comprises a tube or barrel that can be rectilinear or circular in cross section. Sets of sensing ports are utilizied and at least one pair of ports is oriented on a common axis and facing in opposite directions. Reliable sensing can be obtained when two sets of oppositely facing ports are used with the axis of each set 90.degree. to the axis of the other set. By using the pressure sensed in more than one combination, that is by co-using the pressures, static pressure, impact pressure, angle of attack and angle of sideslip can be derived. The ports are positioned on the tapered forward section, rearwardly of the pitot port before the full size of the basic tube is reached, and are positioned very close to the leading end. The tapered forward section expands from the edge of the pitot port a short axial distance, not generally more than eight equivalent radii at the port location, and the ports are positioned greater than one and less than six equivalent radii aft of the pitot tip.

Compact air data sensor

A short multiple static pressure sensing probe that is compensated for both subsonic and supersonic speeds in the same probe and a family of such probes for different aircraft with each of the probes in the family having a common barrel configuration except for the final shaping of compensation surfaces and the location of static pressure sensing ports. In an assembly operation, heaters and interconnecting wires, bulkheads and pressure tubing are arranged, internal to the probe, to stay clear of predetermined areas in which static pressure ports may be located. In a finishing operation, compensation surfaces are produced and static pressure ports are created at selected locations in the predetermined areas, thus avoiding damage to internal parts. A preferred arrangement of compensation surfaces facilitates multiple subsonic and supersonic compensation by providing at least two regions of relatively constant, but selectable, supersonic compensation pressures that coincide along the length of the barrel with two regions of variable subsonic pressures. The supersonic compensation in this preferred arrangement is adjusted to the desired levels by selecting two of the compensation surfaces. The subsonic compensation is then adjusted by selecting a second two of the compensation surfaces and the location of the static pressure ports.

Family of aerodynamically compensated multiple static pressure tubes

A unitized drain manifold apparatus for removing water from air in a conduit of an air data sensor system for an aircraft comprises a manifold having a plurality of drain cavities therein. Each drain cavity has a center chamber portion and two end drain chambers positioned vertically above and below the center chamber portion when the aircraft is at rest. The end drain chambers are used for accumulation of water which is separated from the air pressure signal. The cavities are each equipped with two drain passageways such that the accumulated water can be removed from the apparatus in normal or inverted positions. The positioning of the external drain passageways permits water accumulation and removal to occur independently of the spatial orientation of the apparatus and the symmetry of the manifold permits it to be mounted on either side of the aircraft.

Drain manifold for air data sensor

A test system for air data sensors includes means for mounting the system components directly on the sensor and provides a self contained source of the necessary vacuum or positive pressure as needed for testing the sensor for function. The self contained test system includes manual pressure creating means that is self limiting to prevent excessive pressures being generated. In one form of the invention the entire assembly slips over and is supported on a sensor probe, and includes passageways and connections to provide the fluid pressures required to the sensing ports. In a second form, the self contained test system mounts on the sensor strut and has a pressure fitting that fits over the ends of a probe barrel to provide an adjacent coupling means for supplying the fluid pressures to the respective ports. The test system is a compact, easily mounted unit that is supported directly on the air data sensor being tested, and which has self contained fluid pressure sources for the necessary test. It is easy to use with minimal training of the operators, compact, and does not require any electrical power nor any other power supply.

Test system for air data sensor

The invention comprises an improved sensing instrument (10) for sensing the angular position of the longitudinal axis (17) of a cylindrical sensor body (14) of an object moving relative to a fluid medium with respect to a first plane. Such object has a leading end portion (15) joined to the sensor body (14) and exposed to the fluid medium. A first pair of pressure sensing ports (20 and 21) are on the object and face in the upstream direction and have their axes lying in a second plane at right angles to said first plane and disposed at predetermined angles with respect to the axis (17) of the object. A second pair of pressure sensing ports (22 and 23) on the object have their axes lying in the first plane, such axes being disposed at predetermined angles with respect to the axis (17) of the object. A single pressure port (16) on the object has an axis coinciding with the axis (17) of the object. The improvement comprises the leading end portion ( 15) of the sensor body (14) defining a spherical segment of one base.

Pressure sensing instrument for aircraft

A method and a sensing instrument are claimed for sensing atmospheric pressure. The instrument (24) comprises an enclosure (26) that has a shape exposed to a fluid medium, which fluid medium may be moving at a certain velocity relative to the sensing instrument. The sensing instrument has at least one port (28) open to the fluid medium for sensing the velocity of the medium and for measuring a pressure of the fluid medium. The measured pressure is corrected for the effects of the velocity of the medium according to the formula

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Eden Prairie, MN, United States of America

Floyd W Hagen