Abstract: An aerodynamic noise measurement system for a vehicle uses sound reflectors to determine the sound wave propagation of aerodynamic noise of the vehicle. The vehicle is placed within a test section of a wind tunnel. The air flow of the wind tunnel generates the aerodynamic noise as it passes over the vehicle. An array of sound reflectors is placed outside of the air flow of the wind tunnel. Microphone arrays receive the aerodynamic noise directly from the source and from the sound reflectors. An analyzer system forms an acoustic image of the vehicle based on the aerodynamic noise. A viewing device displays an image of the vehicle with an overlay of aerodynamic noise data in real-time.

Abstract: A damping section, for an aerodynamic wind tunnel having a test section defined by a nozzle mouth at an upstream end and a collector mouth at a downstream end, is adapted to conform to a perimeter of the collector mouth and extend in the downstream end of the test section, and includes a slotted section adapted to dissipate irregularities in the flow of air at the perimeter of the collector mouth.

Abstract: An apparatus for measuring soil stability of a test surface comprising a housing defining an interior chamber, the housing having an open bottom wherein the housing is configured to be placed over the test surface proximate the open bottom. A means for generating wind shear disposed in the interior chamber, the wind shear generating means configured to generate wind shear proximate the test surface and at least one particle monitor in communication with the interior chamber.

Abstract: In the computational fluid dynamics analysis of airfoils, a laminar/turbulent transition location is determined by consideration of a turbulence length scale in addition to a turbulence intensity. In an exemplary implementation, the transition is predicted as occurring when a momentum thickness-based Reynolds number reaches a given exponent of the factor multiplied by a constant. The factor may consist of the turbulence intensity multiplied by a momentum thickness and divided by the turbulence length scale.

Abstract: A lamp assembly for use in a pressure sensitive paint measuring system, such as for measuring pressure on a test air vehicle using pressure sensitive paint, is constructed and configured to provide (1) exceptional cooling for the various optical elements and the housing, (2) a combination of filters that minimizes heat load on the interference filter, yet provides a high beam intensity at the desired wavelength, (3) a mounting structure for the lamp assembly that allows the lamp assembly to be accurately aimed and positioned with little translation of the output aperture, and (4) easy access to the internal components, including the bulb-reflector assembly and optical elements.

Abstract: An apparatus and method is provided for testing at least one performance characteristic of a vehicle.

Abstract: A wind tunnel model for wind tunnel testing having an additional mass mounted on the model via vibration absorbing material to dampen model vibration.

Abstract: A wind tunnel for measuring the aerodynamics of a vehicle may comprise a test section. Air moving through the test section may be collected in a plurality of individual ducts, each with a fan for moving the air through the test section and ducts. The vehicle of vehicle wheels may be supported at an incline.

Abstract: A flutter test model is provided that utilizes a novel approach for fixing wing elements to an elastic spar, resulting in reduced airflow disturbance. A test wing has an elastic spar that simulates the elasticity of a wing of an actual airplane, and a plurality of wing elements that simulate the external shape of the wing of the actual airplane. A pair of fore and aft anchor members are fixed to the elastic spar by bolts, the wing element that is formed by stereolithography is fitted around the anchor members from the wing tip side, and the wing element is fastened to the anchor members by bolts that run through the wing element from the wing tip side. A weight, which is a tungsten rod, is housed in a weight support hole formed in the wing element. The anchor members and the bolts are not exposed on the surface of the wing element and the airflow over the surface of the test wing is not disturbed when a flutter test is carried out in a wind tunnel, thereby enhancing the accuracy of the flutter test.

Abstract: The invention relates to a device for measuring a tire pressure of a tire arranged on a rim (10), having a tire valve (14) arranged in a bore (12) in the rim (10), and a tire pressure sensor unit (16) arranged inside the tire and fastened on the tire valve (14), it being possible to fasten the tire pressure sensor unit (16) in various angular positions with reference to the tire valve (14). It is provided according to the invention that an electric connection (18) exists between the tire pressure sensor unit (16) and the tire valve (14), and that the tire valve (14) is provided as an antenna for communicating with a receiver and/or transmitter arranged outside the tire.

Abstract: The invention pertains to a process for determining aerodynamic parameters of an airflow surrounding an aircraft. On the basis of at least two probes situated on the skin of the aircraft, each probe comprising means for measuring the local angle of attack (?loc i, ?loc j), the process consists in determining the angle of attack (?) and/or sideslip (?) of the aircraft, as a function of the local angle of attack of each probe and of the aerodynamic field of the aircraft. The invention also pertains to a process for detecting a fault with a probe used to determine the aerodynamic parameters of the airflow surrounding an aircraft.

Abstract: A method is used for checking the air noise of a motor vehicle, particularly of a passenger car, which air noise is generated by air flowing onto an outer skin of a vehicle body of the passenger car. In order to optimize this method, targeted air currents are applied by means of a blower to a stationary passenger car in areas where sealing devices extend between stationary vehicle body structures and movable vehicle body elements of the vehicle body, and the air noise occurring as a result of the air currents is measured subjectively and/or objectively. For the implementation of the method, a device is used in the case of which the blower comprising the outflow cross-section is a component of a flow device which is equipped with a blast nozzle for acting upon measuring points on the outer skin.

Abstract: A reduced drag cable for use in vertical wind tunnels and other applications with a change in the spacing and/or size of the strands of a standard twisted wire cable is disclosed. The perimeter strands of one embodiment all have a standard diameter, with the exception of one or more wires with different diameter from the other perimeter strands. The different sized strand forms a helical feature around the cable, creating a non-circular profile to reduce drag in air.

Abstract: Apparatus and methods for airflow testing, especially for air testing of gas turbine components on an airflow test bench. Various embodiments of the present invention include the use of a flow-stabilizing member downstream of the component being tested. Since the flow through or over the component is subsonic, a flow-stabilizing member placed down stream of the component can have an effect on the flow conditions in or around the component being tested. In one embodiment, the flow-stabilizing member provides more consistent results during the testing of the component.

Abstract: An open jet wind tunnel having a test section, a nozzle exit and a collector in which the leading edge of the collector is configured with at least a portion being non-uniformly spaced from the nozzle exit.

Abstract: A method for locating two dimensional critical flow features on a surface of a three dimensional body immersed in a fluid stream is presented. The method includes applying a hot film sensor array on the surface of the body. The hot film sensor array includes a plurality of hot film sensor elements disposable in a two dimensional array over at least a portion of the body surface. Each sensor element is connected to an associated anemometer circuit to provide an output voltage. The method further comprises obtaining output voltage data for each hot film sensor element with the body immersed in the fluid stream under a set of flow conditions and processing the hot film sensor element output voltage data to locate at least one two dimensional critical flow feature on the body surface.

Abstract: A positioning system is provided for use in a wind tunnel that results in accurate and dynamic orientation for a model while reducing aerodynamic interference. The system includes a pitch-yaw sleeve having a generally cylindrical shape and a torque tube disposed askew within the sleeve and rotatable about its longitudinal axis to drive a shaft. The shaft is generally elongated and crooked. The sting, to which a model is affixed, is rotatably attached to a distal end of the shaft. Rotation of the pitch-yaw tube and/or the pitch-yaw sleeve provides precise pitch and yaw orientation of the model, and rotation of the sting relative to the shaft provides precise roll orientation.

Abstract: Apparatus and methods for airflow testing, especially for air testing of gas turbine components on an airflow test bench. Various embodiments of the present invention include the use of a measurement section downstream of the component being tested. The measurement section, in one embodiment, includes apparatus for measurement of gas properties at a plurality of spaced-apart radial locations and/or a plurality of spaced-apart circumferential locations. In another embodiment, the invention includes a method for testing a component including a comparison of gas properties measured in both forward and reverse flow directions.

Abstract: A method is provided for determining a load on an object immersed in a fluid stream under a set of flow and attitude conditions associated with unsteady flow phenomena. The method comprises measuring surface heat transfer at a plurality of surface locations on the object under the flow and attitude conditions to provide a set of heat transfer data. The heat transfer data are used to determine an indicator surface location of at least one critical flow feature indicator. The method further comprises calculating a load coefficient using the indicator surface location of the at least one critical flow feature indicator and calculating the load from the load coefficient and the flow and attitude conditions.

Abstract: A wind tunnel for measuring the aerodynamics of a vehicle may comprise a test section. Air moving through the test section may be collected in a plurality of individual ducts, each with a fan for moving the air through the test section and ducts. The vehicle or vehicle wheels may be supported at an incine.

Abstract: A multi faceted system for simulating free flight, playing games in a free flight mode, and photographing the experience in a manner which permits of the creation of a montage, in which a vertical air column is defined by a variable cylindrical walls, and in which at least a portion of the air column is moving in laminar flow mode.

Abstract: Apparatus and methods for airflow testing, especially for air testing of gas turbine components on an airflow test bench. Various embodiments of the present invention include the use of a measurement section downstream of the component being tested. The measurement section, in one embodiment, includes apparatus for measurement of gas properties at a plurality of spaced-apart radial locations and/or a plurality of spaced-apart circumferential locations. In another embodiment, the invention includes a method for testing a component including a comparison of gas properties measured in both forward and reverse flow directions.

Abstract: A wind tunnel model design employs a reinforcing strongback 10, made of a rigid material, for receiving a balance 12. At least one jacket section 14, made of a rapid prototype (RP) material, fits over the strongback 10 and defines at least part of an aerodynamic surface. Other aerodynamic surfaces, made of either RP materials or conventional metal materials, may be attached directly to the strongback 10.

Abstract: Apparatus and methods for airflow testing, especially for air testing of gas turbine components on an airflow test bench. Various embodiments of the present invention include the use of a measurement section downstream of the component being tested. The measurement section, in one embodiment, includes apparatus for measurement of gas properties at a plurality of spaced-apart radial locations and/or a plurality of spaced-apart circumferential locations. In another embodiment, the invention includes a method for testing a component including a comparison of gas properties measured in both forward and reverse flow directions.

Abstract: An improved tunnel or covered highway structure with means for easy and quick access to the interior. The structure includes a wind tunnel built over a highway and a wind deflector slab provided near the exit end of the tunnel and having an opening for permitting vehicular traffic to pass therethrough. The wind deflector functions to deflect upwardly the air flow generated by the piston action of traffic moving in the tunnel so as to diffuse air pollutants such as carbon monoxide and traffic noise. The wind tunnel includes vent openings and/or side entrances which are normally closed to prevent ventilation of the tunnel therethrough but can selectively be opened to reduce wind pressures generated by piston action of the moving traffic so that the operation of maintenance personnel may not be hampered thereby during repairs.

Abstract: An open jet wind tunnel having a test section, a nozzle exit and a collector in which the leading edge of the collector is configured with at least a portion being non-uniformly spaced from the nozzle exit.

Abstract: An open jet wind tunnel having a test section, a nozzle exit and a collector in which the leading edge of the collector is configured with at least a portion being non-uniformly spaced from the nozzle exit.

Abstract: A method and apparatus are presented for determining turbulent boundary layer thickness. In this method and apparatus, a pair of sensors are mounted to a solid surface interfacing with a fluid at two separate stream wise locations. A voltage output from the pair of sensors is recorded and a real non-dimensional value of a correlation coefficient is computed with measured data from the recorded voltage. A laboratory non-dimensional value of the correlation coefficient is independently determined from laboratory data. The real non-dimensional value is compared with the laboratory non-dimensional value to obtain a boundary layer thickness having a value which minimizes a difference between the values of the real non-dimensional value and the laboratory non-dimensional value.

Abstract: A wind tunnel and a heat exchanger for use in the wind tunnel. The heat exchanger is a plate-fin type heat exchanger having at least one heat exchanger unit with an inflow end and an outflow end, and air flow section and a coolant flow section. The air flow section includes fins generally aligned with the air flow through the exchanger and the coolant flow section includes fins defining a coolant passageway.

Abstract: A method and apparatus are presented for determining turbulent boundary layer thickness. In this method and apparatus, a pair of sensors are mounted to a solid surface interfacing with a fluid at two separate stream wise locations. A voltage output from the pair of sensors is recorded and a real non-dimensional value of a correlation coefficient is computed with measured data from the recorded voltage. A laboratory non-dimensional value of the correlation coefficient is independently determined from laboratory data. The real non-dimensional value is compared with the laboratory non-dimensional value to obtain a boundary layer thickness having a value which minimizes a difference between the values of the real non-dimensional value and the laboratory non-dimensional value.

Abstract: The present invention discloses an airflow capture booth with single-plate windbreak comprising an extracting means for extracting polluted air having an opening for air contamination extracting through and a crosswind device for simulating crosswind, the improvement comprises that said crosswind device having a single-plate windbreak perpendicular to an airflow direction of said crosswind having a specific distance to said opening of said extracting means for forming a capture zone, wherein the airflow of said capture zone is not easy to be shed and is extracted mostly by said extracting means.

Abstract: The operating efficiency of a compressor in the range of low Mach numbers at a supersonic wind tunnel test section (for which a considerable flow rate is required) is emphasized, and a design is provided in which pressure fluctuations can be reduced in a supersonic flow and also can be reduced in a supersonic wind tunnel circuit capable of operating at the required Mach number. Pressure fluctuations of flow brought about by inefficient operation can be reduced by operating an axial compressor 9 at a higher operating efficiency in the presence of a tunnel circuit resistor than the operating efficiency determined by the operating state theoretically calculated based on the Mach number required at a test section 19 in the absence of the tunnel circuit resistor. The Mach number at the test section can be made to conform to the required Mach number by causing the stream produced by the axial compressor 9 to pass through the tunnel circuit resistor such as a mesh plate 20 mounted in the tunnel circuit.

Abstract: In a method of controlling vortex breakdown on an aerodynamic surface, a vortex generated by the aerodynamic surface is continually monitored to identify a non-linear region where vortex breakdown occurs. A fluid jet is blown into the non-linear region to displace the vortex breakdown to a target location. A blowing parameter for the fluid jet is continually adjusted to continually direct the fluid jet into the vortex breakdown region and preferably ensure maximum positive feedback. The fluid jet is dynamically displaced toward the sensitive spot to maximize the effectiveness of the jet.

Abstract: A wind tunnel model for wind tunnel testing having an additional mass mounted on the model via vibration absorbing material to dampen model vibration.

Abstract: A method for the accurate positioning of a vehicle to be examined aerodynamically in a measurement position in a wind tunnel, in which it assumes an accurately predefined relative position in relation to the axis of the wind tunnel, the measurement object is supported in the measurement position, in a stable position on the floor or on balance standing points in the wind tunnel, by auxiliary supports, in the case of a motor vehicle via its wheels. Outside the wind tunnel, the measurement object is placed onto a measurement-object carrier that can be moved at least in the longitudinal direction of the measurement-object carrier and is aligned accurately with respect to the latter. The measurement-object carrier with the aligned measurement object is moved into the wind tunnel and stopped in the latter in an accurately predefined position.

Abstract: A system for aerodynamically testing a vehicle having a front pair of wheels and a rear pair of wheels includes a surface for statically supporting the vehicle. The system additionally includes a primary source of air directed towards the vehicle. The primary source of air aerodynamically simulates conditions for the vehicle at a predetermined speed. The system further includes a first supplemental source of air directed into a flow of air generated by the primary source of air immediately behind the first pair of wheels.

Abstract: A device supports a motorized flying instrument in a wind tunnel. To carry out tests in a wind tunnel on a motorized flying instrument (10), with the motor on, under different attitudes hands off, the instrument is connected to the fixed structure (15) of the wind tunnel (11) by a mounting device (12) at least one of the supports (14, 16) of which is fitted with a length adjustment system, such as a hydraulic jack (28). This jack (28) is remote controlled, in real time, by a control system (42).

Abstract: A simultaneous measurement of small displacements, from which forces, moments, pressures, and other physical quantities can be determined, with a high degree of precision and accuracy. A computer may be used to resolve the displacement into the applied loads. More specifically, a class of precision instruments is provided whose chief task is to resolve the applied loads acting on a body into their component forces and moments relative to a fixed coordinated axis system. This class of instruments includes the measurement of forces and moments acting on models tested in aerodynamic wind tunnel facilities.

Abstract: A wind tunnel for measuring the aerodynamics of a vehicle may comprise a test section. Air moving through the test section may be collected in a plurality of individual ducts, each with a fan for moving the air through the test section and ducts. The vehicle or vehicle wheels may be supported at an incine.

Abstract: An aircraft engine run-up hangar comprises a building defining a test chamber capable of receiving an aircraft therein, an air inlet structure, and an exhaust structure. The air inlet structure is formed in a front end part of a roof structure corresponding to a front end part of the building. The exhaust structure is connected to a rear end part of the building and defines an exhaust passage extending obliquely upward from the back end of the building. A ceiling included in the building has an inclined section sloping down backward to straighten air currents, and a groove is formed in a middle part, with respect to width, of the inclined section to permit a vertical tail fin of an aircraft to pass when the aircraft is carried into or out of the test chamber.

Abstract: A measuring apparatus for measuring the volume of a contained fluid includes an exposure chamber adapted for exposure to head volume of a volume of the contained fluid. A displacement mechanism is connected to the exposure chamber such that the displacement mechanism is displaced in proportion to the amount of head volume in the contained fluid acting on the exposure chamber. A read mechanism is connected to the displacement mechanism. The read mechanism generates a signal corresponding to the amount of displacement of the displacement mechanism.

Abstract: A model for a wind tunnel test fabricated at a low cost, in which a plurality of small bores opening on a surface of a wing and a plurality of passages permitting the small bores to communicate therewith. The plurality of small bores and the plurality of passages are so disposed that they do not interfere with each other.

Abstract: Disclosed is a noise source visualizing system used in a wind tunnel test to measure generated sounds, the system comprising an acoustic mirror for converging sound waves of sounds generated on a surface of a vehicle during a wind tunnel test; a microphone measuring the converged sound waves; an image-photographing unit photographing locations on the vehicle at which the sounds are generated; a first display unit displaying the sounds measured by the microphone as colors that vary according to characteristics of the sounds; a movable traverse to which the acoustic mirror is connected for enabling the acoustic mirror to collect the sounds; a workstation for analyzing the converged sound waves measured by the microphone, the images photographed by the image-photographing unit, and the signals displayed through first display unit; and a second display unit overlapping then displaying image signals photographed by the image-photographing unit and the colors displayed on the first display unit.

Abstract: An open jet wind tunnel having a test section, a nozzle exit and a collector in which the leading edge of the collector is configured with at least a portion being non-uniformly spaced from the nozzle exit.

Abstract: The operating efficiency of a compressor in the range of low Mach numbers at a supersonic wind tunnel test section (for which a considerable flow rate is required) is emphasized, and a design is provided in which pressure fluctuations can be reduced in a supersonic flow and also can be reduced in a supersonic wind tunnel circuit capable of operating at the required Mach number. Pressure fluctuations of flow brought about by inefficient operation can be reduced by operating an axial compressor 9 at a higher operating efficiency in the presence of a tunnel circuit resistor than the operating efficiency determined by the operating state theoretically calculated based on the Mach number required at a test section 19 in the absence of the tunnel circuit resistor. The Mach number at the test section can be made to conform to the required Mach number by causing the stream produced by the axial compressor 9 to pass through the tunnel circuit resistor such as a mesh plate 20 mounted in the tunnel circuit.

Abstract: In a method of controlling vortex breakdown on an aerodynamic surface, a vortex generated by the aerodynamic surface is continually monitored to identify a non-linear region where vortex breakdown occurs. A fluid jet is blown into the non-linear region to displace the vortex breakdown to a target location. A blowing parameter for the fluid jet is continually adjusted to continually direct the fluid jet into the vortex breakdown region and preferably ensure maximum positive feedback. The fluid jet is dynamically displaced toward the sensitive spot to maximize the effectiveness of the jet.

Abstract: A support device for a motorised flying instrument in a wind tunnel.

Abstract: A turbulent layer detecting apparatus in accordance with the present invention is equipped with a transmitting section that transmits beams of electromagnetic waves, sound waves or light waves into the atmosphere, a receiving section that receives the electromagnetic waves, the sound waves, or the light waves that have been transmitted by the transmitting section and scattered by particulates or the like in the atmosphere, a wind velocity measuring section that measures a beam direction component of a wind velocity at two or more observation points on a beam from a received signal received by the receiving section, or a density measuring section that measures a density at two or more observation points on the beam, and a turbulent layer detecting section that detects the presence of a turbulent layer on the basis of the output of either the wind velocity measuring section or the density measuring section.

Abstract: A wind tunnel model design employs a reinforcing strongback 10, made of a rigid material, for receiving a balance 12. At least one jacket section 14, made of a rapid prototype (RP) material, fits over the strongback 10 and defines at least part of an aerodynamic surface. Other aerodynamic surfaces, made of either RP materials or conventional metal materials, may be attached directly to the strongback 10.

Abstract: An optical configuration and related analysis techniques are presented that provide a practical method for determining the Rytov parameter based on the difference of variances for the differential image motion (average wavefront gradient or wavefront tilt) between two receiving apertures. The Rytov parameter is the log-amplitude variance predicted by an approximate solution to Maxwell's equations for propagation through media with random index of refraction (Rytov theory). It is a useful metric of the optical effects for extended turbulence propagation and is a leading indicator of the performance limitations of adaptive optical compensation devices not related to the transverse coherence diameter. A time-duplex alternative apparatus and a single source alternative apparatus are also disclosed.