Abstract: A low speed wind tunnel with an adjustable moving boundary is disclosed. The wind tunnel comprises a wind tunnel test section having at least one movable wall installed therein. The movable wall is capable of moving with the same direction and speed of the air flow. The movable wall may be a roller tread or a roller belt. A nested filter is installed at an inlet site of the air flow for regulating a source air flow into an evenly distributed flow field which is then sent to the wind tunnel test section. The nested filter includes a plurality of nested units arranged in order. Each nested unit has an air flow cross. section adjustable structure for varying the cross section area of the air flow passing through the wind tunnel test section, thereby adjusting the speed of the air flow. The movable wall may be designed to be an adaptive boundary for corresponding with different shapes of objects under test located in the wind tunnel test section.

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 method for computing three dimensional unsteady flows about an object. An allowable error is established for the vorticity term calculations, and object geometry is provided giving surface points on an object and a region of interest. A mesh is established incorporating points on the object. Initial flow conditions are set at the surface. Vorticity values that will satisfy boundary conditions are set at the provided surface points. A new mesh is established incorporating the provided points and other points in the region of interest. Boxes are generated containing the provided points and other points. Velocities and pressures at each point are calculated from the flow conditions, vorticity values and boundary conditions., A time variable is incremented and each point is moved by applying the calculated velocity. Vorticity at each point is then recalculated. The method is iterated starting with the step of satisfying boundary conditions until the incremented time variable exceeds a predetermined value.

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 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: A housing for an electronic monitoring device on a vehicle part such as a lead accumulator comprises a metallic, load-bearing baseplate and an injection molded, generally parallelepipedal housing body encapsulating the baseplate. The baseplate projects out of the housing body on at least one side with a cantilevered attachment section.

Abstract: A low speed wind tunnel with an adjustable moving boundary is disclosed. The wind tunnel comprises a wind tunnel test section having at least one movable wall installed therein. The movable wall is capable of moving with the same direction and speed of the air flow. The movable wall may be a roller tread or a roller belt. A nested filter is installed at an inlet site of the air flow for regulating a source air flow into an evenly distributed flow field which is then sent to the wind tunnel test section. The nested filter includes a plurality of nested units arranged in order. Each nested unit has an air flow cross section adjustable structure for varying the cross section area of the air flow passing through the wind tunnel test section, thereby adjusting the speed of the air flow. The movable wall may be designed to be an adaptive boundary for corresponding with different shapes of objects under test located in the wind tunnel test section.

Abstract: A sensor (210) for increasing signal time employs a resiliently deflectable member n(218) with a pressure sensitive signal element (216) and base member (222). The dampening effect of the elastic material provides a longer signal response time that allows sufficient time for a system to react without a need for additional signal conditioning circuitry. Sensor (10, 110) senses a selected path of movement for a moveable element (8) and establishes a signal indicative thereof. The limit sensor includes a resiliently deflectable member (18) for activating the signal at a predetermined station along the preselected path of movement and includes a base member (22) for supporting the resiliently deflectable member (18) and the pressure sensitive signal element (16). An actuator (20) receives the force (F) from the moveable element (8) and transfers the force (F) to the pressure sensitive signal element (16).

Abstract: The present invention provides an apparatus for redirecting air flow, and more particularly, an apparatus for efficiently generating a vertically directed air flow having a generally uniform velocity profile from a horizontally oriented fan. In particular, the present invention provides an apparatus for redirecting a three-dimensional inwardly directed flow to a planar radially inward directed flow, as well as an apparatus for redirecting a generally horizontal planar radially inward directed flow to a vertically outward directed flow, perpendicular to the radial inward directed flow, having a relatively uniform velocity profile across the cross section of the flow.

Abstract: A device for encapsulating a monitoring device for a pneumatic tire with an encapsulation material includes an encapsulation body having an encapsulation chamber. The monitoring device has at least a pressure sensor and an antenna. A damming element is carried by the encapsulation body in an adjustable manner such that the damming element prevents the pressure sensor from being clogged with the encapsulating material when the monitoring device is encapsulated.

Abstract: A micro-dimensional sensor measures the shear force, both in magnitude and direction, at the surface of a solid boundary as a fluid flows over that boundary. The sensor is a micro-mechanical capacitor-transducer system that includes a micro-dimensioned floating upper plate above a fixed lower plate supported on a substrate. The floating upper plate is mounted and held over the substrate by a number of zig-zap form supporting arms. The flow passing over the upper plate displaces the upper plate in a downstream direction, which results in a measurable change of the capacitance in the capacitor-transducer system. The direction and magnitude of the shear forces can then be obtained from the measured capacitance through specially designed circuitry.

Abstract: An arithmetic processing method and system in a wide velocity range flight velocity vector measurement system using a square truncated pyramid-shape five-hole Pitot probe. Approximation equations that determine attack angle &agr; and sideslip angle &bgr; in the form of third-order equations concerning attack angle pressure coefficient C&agr; and sideslip angle pressure coefficient C&bgr;, which are known numbers, are expressed in the form of a polynomial equation concerning Mach number M, where the coefficients are obtained from a lookup table.

Abstract: The invention relates to a device which determines aerodynamic characteristics of a wall. The device comprises a drum secured to a shaft, an enclosure defining with the drum at least one test zone (10a; 40a), a test fluid delivery line communicating with this test zone and means which determines a parameter representative of the friction factor of the fluid in the at least one test zone. The at least one test zone has a determined width 1 or gap width, for a given rotating speed of the drum and a test fluid having known characteristics (visosity, density . . . ), so that the fluid has a turbulent flow in the vicinity of the wall(s) to be tested, the turbulent flow corresponding to a given Reynolds value Re.

Abstract: A wind tunnel consisting of a closed loop passageway including a test station and an impellor for producing an air stream through such passageway, a device for detecting the standing sound wave of such air stream at the test station and control means responsive to such standing sound wave for propagating at least one sound wave of a selected phase at a point in such air stream to nullify such standing sound wave.

Abstract: The present invention is a vertical wind tunnel amusement device. The device comprises a flight chamber wherein a user may experience a freefall through the atmosphere from the safety of an enclosed flight chamber. Airflow sufficient to fully support a user within the flight chamber is induced by a plurality of fans connected above the flight chamber through a duct. A staging area having openings to the flight chamber is adjacent to the flight chamber. A user may enter or retreat from the flight chamber at will through the staging area openings without significantly adjusting the airflow velocity in the flight chamber. A control room is adjacent to the fight chamber whereby an operator may observe a user or users within the flight chamber and thereby safely control the operation of the fans. A projection room is also adjacent to the flight chamber whereby a video of a skydiving experience may be displayed to a user within the flight chamber.

Abstract: An assembly for positioning a measurement probe proximate a test body disposed for a fluid tunnel test includes a frame having a forward frame portion for attachment to a fluid flow tunnel fluid outlet, an aft frame portion aligned with the forward frame portion, and axial support members interconnecting the forward and aft frame portions. The assembly further includes a probe mount portion having a base slidably mounted on one or more of the axial support members, a probe supporting strut mounted on the base, and a probe mounted in the strut and movable in directions radially of the frame, and a probe moving member for moving the probe radially inwardly and outwardly of the frame portions.

Abstract: A heat transfer-based surface flow visualization method and device that uses a temperature sensitive material to detect advection along a substrate upon application of heat and air flow and thereby provides a surface flow pattern. The present invention includes the capability of providing surface flow patterns for positions of flow separation, reversal of flow and transition flow and is non-intrusive and more cost effective than known methods.

Abstract: Apparatus for simulating aerodynamic heating and cooling on the outer surface of equipment externally mounted on an aircraft or missile as if airborne and exposed to an air stream. A first proximately spaced enclosure substantially uniformly conforms to the outer surface of the equipment and defines a low pressure chamber. A second enclosure envelops the first enclosure and defines a high pressure chamber. An adjustable flow producing mechanism directs flow of pressurized inlet air into the high pressure chamber. A temperature control mechanism selectively heats and cools the inlet air. Vents in the second enclosure exhaust the air from the low pressure chamber to the ambient region and a plurality of spaced orifices in the first enclosure direct jets of the pressurized air from the high pressure chamber into the low pressure chamber which vigorously impinge on the outer surface of the equipment.

Abstract: The development of a nearly-omni-directional pressure probe for three-velocity-component and pressure measurements is described, with particular focus on the techniques and technology employed in probe construction, calibration, electronic interfacing and frequency-response study. The device eliminates the velocity directionality limitations of current multi-hole probes and makes a valuable, rugged tool for use in complex 3-D flow mapping and aerodynamic design and evaluation, in basic research as well as industrial development settings. The probe performance is demonstrated in a flowfield with flow reversal downstream of a backward-facing step. The probe provides low-frequency response capabilities. The probe's main element is a multi-pressure port spherical head, which may include eighteen ports. Fiber optic interferometry techniques may be incorporated to significantly increase frequency response.

Abstract: A drag balance for measuring drag forces on a model is described which mos within a hollow region of a streamlined strut. The strut is attached to a carriage for towing the model through a medium. The drag balance has a ground frame attached inside the strut and a balance frame attached to the flat plate at the base of the strut. The ground frame and balance frame are connected by flexures which allow only a small amount of movement of the balance frame and model relative to the ground frame and strut in the towing direction. Strain gages are attached to one or more of the flexures to determine the amount of bending in the flexures and thus obtain a measure of the drag forces exerted on the model. Mounting the drag balance within the streamlined strut minimizes turbulence and allows the drag balance to be connected directly to the model at the base of the strut such that drag forces on the model are accurately determined.

Abstract: An instrumented device for the study of airflow over a structure (10), comprises a support (16) forming a thin plate (24) adapted to be applied and shaped to the contour of a predetermined region of the structure. Connection structure (22) cements a portion of an inner surface of the support to that predetermined region, leaving a space (36) of low height between an inner surface of the plate (24) of the support and that predetermined region. This height is substantially equal to the thickness of said cementing structure. Instrumentation (18) is connected to the support, a portion (28) of this instrumentation and wire connections (20) therefor being disposed in that space (36), whereby the device is adapted to form a skin on the structure.

Abstract: This invention provides a system for measuring and comparing various characteristics of a motor fan rotated by a power generating unit, the system including the power generating unit for rotating the fan, a housing containing the power generating unit therein and being formed with a suction inlet for drawing air during rotation of the fan and a discharge outlet for discharging the air absorbed through the suction inlet, a supporting unit installed into the housing for supporting the power generating unit, a protection unit having in a front surface thereof a suction hole for drawing the air, for protecting breakage of the fan, a vacuum measuring unit installed to measure a vacuum in the housing, a wind amount regulating unit for controlling a draining port of the housing so as to maintain optimal vacuum in the housing, a revolution measurement unit for measuring revolution of the rotating unit installed to the power generating unit, and a torque table for measuring torque.

Abstract: A transportable three-dimensional calibration wind tunnel system is comprised of a small wind tunnel portion for creating a three-dimensional calibration air having a suitable wind velocity, and a two-axis rotational deformation device portion for causing said wind tunnel portion to effect a conical motion with a nozzle blow port being an apex to suitably change a flow angle. The two-axis rotational deformation device is comprised of a .beta.-angle rotational deformation device having a .beta.-angle deformation base supported to be rotated horizontally, and a .alpha.-angle rotational deformation device having a .alpha.-angle deformation base supported to be rotated vertically. A rotational axis of the .alpha.-angle deformation base, a rotational axis of the .beta.-angle deformation base and a center axis of the small wind tunnel portion are arranged so that they intersect at a point.

Abstract: The present invention provides a new synchronized optical method for measuring surface pressure on rotating objects such as propellers or other rotating objects. The technique is based on the phenomenon of oxygen quenching of luminescence coatings and synchronized optical imaging. A surface coating, referred to as a pressure sensitive paint (PSP), is formed by mixing photo-luminescence molecules in an oxygen permeable polymer. The luminescence excited by an appropriate light source decreases as the oxygen concentration rises due to quenching. As a result, the luminescence intensity of light emitted from the coating varies as a function of the partial pressure of oxygen. A digital camera measures the luminescence intensity distribution over the object and the pressure distribution can be computed.

Abstract: A system and method for creating visual images of aircraft wake vortices allows a user, such as an aircraft controller, to increase a number of airport transactions while maintaining a predetermined level of safety. Wake vortices are simulated in a three dimensional environment taking into account various aircraft, environmental, and atmospherical conditions. The simulated wake vortices are rendered from a perspective selectable by the user. The displayed image allows the user to direct aircraft around potentially harmful wake vortices.

Abstract: A method and apparatus for controlling the level of relative humidity within a corrosion test apparatus is disclosed. The corrosion test apparatus includes a testing chamber, an atomizer which fogs the testing chamber with de-ionized water, a sensor which senses a relative humidity level within the testing chamber, a humidifying valve coupled to the atomizer which regulates a supply of pressurized air to the atomizer, and a controller coupled to the sensor and to the humidifying valve. The controller includes a heating control loop mechanism which generates an output signal proportional to a differential between a relative humidity set point and the relative humidity level. The humidifying valve regulates the supply of operating medium to the atomizer based on the output signal. The atomizer regulates the amount of operating liquid fogged into the test chamber based on the supply of operating medium received from the humidifying valve.

Abstract: A method of forming a hot film sensor directly on a model is provided. A polyimide solution is sprayed onto the model. The model so sprayed is then heated in air. The steps of spraying and heating are repeated until a polyimide film of desired thickness is achieved on the model. The model with the polyimide film thereon is then thoroughly dried in air. One or more hot film sensors and corresponding electrical conducting leads are then applied directly onto the polyimide film.

Abstract: A transportable three-dimensional calibration wind tunnel system consisting of a small wind tunnel portion for creating a three-dimensional airflow having a suitable wind velocity, and a two-axis rotational deformation device portion for causing the wind tunnel portion to effect a conical motion with a nozzle blow port being in close proximity to an apex to suitably change a flow angle. The two-axis rotational deformation device includes a .beta.-angle rotational deformation device having a .beta.-angle deformation base supported to be rotated horizontally, and an .alpha.-angle rotational deformation device having an .alpha.-angle deformation base supported to be rotated vertically. A rotational axis of the .alpha.-angle deformation base, a rotational axis of the .beta.-angle deformation base and a center axis of the small wind tunnel portion are arranged so that they intersect at a point.

Abstract: The invention as disclosed herein teaches apparatus whereby the instantaneous dynamic static pressure and the steady-state static pressure may be simultaneously measured within a supersonic or subsonic gaseous fluid flow field. The dynamic static pressure is measured by an electronic transducer and the steady-state static pressure is measured by pneumatic means.

Abstract: An aerodynamic tunnel particularly suited for entertainment purposes is disclosed. The aerodynamic tunnel includes a converging section and a diffuser system having one or more vertical diffusers all of which cooperate with each other to efficiently produce a vertical column of air that allows a person, positioned within the air column, to experience a state of weightlessness.

Abstract: A method of determining pressure requires that a three dimensional surface of an object (14) be covered with a pressure sensitive coating. Next a raw first image (74) is acquired while the object (14) is not under test and a raw second image (74) is acquired while the object is under test. The raw first image (74) and the raw second image (74) are adjusted for a dark image (76) to form an adjusted first image and an adjusted second image. The adjusted first image and the adjusted second image are mapped (78) from a two dimensional representation onto a three dimensional model, to form a first model and a second model. A ratio model is formed (80) by taking the ratio of the intensity of the first model and the second model. Finally, a pressure is determined (84) for every surface that forms the three dimensional model.

Abstract: A modal survey flexure fixture of designed to be soft laterally and stiff axially to simulate the same behavior of space shuttle flight latches which support shuttle payloads for payload modal survey verification, qualification and test. The device consists of three major components: an A-Frame which supports flexure rods attached to a trunnion clamp. Flexure rods made of stainless steel with a partially reduced cross section at both ends increase the lateral flexibility for simulating flight conditions. The trunnion clamp is a unique design which takes into account payload integration with the test fixture. The trunnion clamp can be split into upper and lower portions. During the modal survey the lower trunnion clamp acts initially as a place holder for payload installation and alignment. After payload installation and alignment the lower trunnion clamp is combined with the upper trunnion clamp to complete the test fixture configuration.

Abstract: A six component balance for use in measuring forces and moments on an aircraft model in a wind tunnel or the like. The balance is mounted on a wind tunnel sting by means of a sleeve that surrounds and is spaced from a central core. The central core is connected to a model by support bars passing through slots in the sleeve from the core. Core ends are secured to the sleeve and support the central core through a plurality of webs. A plurality of strain gages are mounted on the webs to detect strain on the webs resulting from forces and moments applied to the model. This system measures six components, i.e., lift force, drag force, side force, pitching moment, yawing moment and rolling moment.

Abstract: The method and apparatus includes a neural network for generating a model of an object in a wind tunnel from performance data on the object. The network is trained from test input signals (e.g., leading edge flap position, trailing edge flap position, angle of attack, and other geometric configurations, and power settings) and test output signals (e.g., lift, drag, pitching moment, or other performance features). In one embodiment, the neural network training method employs a modified Levenberg-Marquardt optimization technique. The model can be generated "real time" as wind tunnel testing proceeds. Once trained, the model is used to estimate performance features associated with the aircraft given geometric configuration and/or power setting input. The invention can also be applied in other similar static flow modeling applications in aerodynamics, hydrodynamics, fluid dynamics, and other such disciplines.

Abstract: A support (11) for a wind tunnel model (10) has a sting (12) provided with a balance (16) carrying the model (10). On the basis of deformations of the balance (16), the wind forces acting on the model (10) can be measured. The balance (16) together with the model (10) forms a vibrating mass-spring system. For elimination of the vibrations, a counter vibration generator (15) is provided, arranged in serial arrangement with the balance (16).The counter vibration generator (15) is controlled, in dependence on signals of the balance (16) or other sensors describing the movements of the model (10), to cause counter vibrations for compensating the natural vibrations of the model (10).

Abstract: A transportable three-dimensional calibration wind tunnel system consists of a small wind tunnel portion for creating a three-dimensional airflow having a suitable wind velocity, and a two-axis rotational deformation device portion for causing the wind tunnel portion to effect a conical motion with a nozzle blow port being in close proximity to an apex to suitably change a flow angle. The two-axis rotational deformation device includes a .beta.-angle rotational deformation device having a .beta.-angle deformation base supported to be rotated horizontally, and an .alpha.-angle rotational deformation device having an .alpha.-angle deformation base supported to be rotated vertically. A rotational axis of the .alpha.-angle deformation base, a rotational axis of the .beta.-angle deformation base and a center axis of the small wind tunnel portion are arranged so that they intersect at a point.

Abstract: An adaptive wind tunnel wall system for minimizing aerodynamic wall interference for slotted or perforated wall test sections. In the present invention, a plurality of continuous or segmented flexible strips may be deflected by a number of actuators to control fluid flow from the test section to a plenum or plena surrounding the test section. The actuators move the continuous or segmented strips toward and away from the slotted or perforated test section walls along the length of the test section to easily change wall crossflow resistance.

Abstract: An orthogonal shear stress measurement probe assembly is provided for meaements away from a solid surface or a vehicle wall. The assembly includes a plurality of micron-sized floating element drag sensors mounted on a 2 mm stainless steel needle. The needle is in turn supported by a streamlined probe which provides both a support for the needle-drag sensor assembly and a conduit for electrical lead. The electrical leads connect the drag sensing elements, which contain piezo-resistive elements, to an external portion of a bridge. These resistive elements form one-half of a bridge, the remaining bridge elements, amplifiers, read-out circuits and power supply are located outside the probe.

Abstract: A pressure sensitive paint is coated onto the surface over which a pressure distribution is to be measured, such as in a wind-tunnel test of an aerodynamic body. A pressure sensitive paint is a mixture of a photoluminescent-compatible, oxygen-permeable binder that is a mixture of silanol-terminated polydimethylsiloxane and methyltriacetoxysilane, and a photoluminescent active agent such as tris(4,7-diphenyl-1,10-phenanthroline) ruthenium(II) chloride pentahydrate. The binder and active agent are placed into an appropriate amount of a solvent for the binder and the active agent, such as dichloromethane, and applied to a surface. In testing of the surface such as wind tunnel testing, the active agent quantitatively luminesces responsive to the local external pressure at the surface.

Abstract: A free piston shock tube/tunnel and a diaphragm construction for a free piston shock tube tunnel in which the diaphragm is provided with multiple rupture areas.

Abstract: Fluid flow characteristics are calculated directly from a two dimensional rface model of the object. A plurality of surface nodes with defined boundary conditions are established on the surface model. Consecutive layers of nodes are created a preset distance outward from said surface model. Curved panels are defined passing through three nodes at a layer, and a surface shape function is established for each panel from previous panels or from the boundary conditions. The fluid flow velocity for the next layer is developed from the velocities calculated at the previous layer and the shape function. Triangular elements are created by connecting a node on the next layer with two nodes from the previous layer to form an element. First and second vorticity gradients can be calculated for the current node at a time segment from the parameters associated with the previous layer of interest nodes at that time increment.

Abstract: A mobile, transportable ground level skydiving simulator apparatus is provided that includes a collapsible air containment unit for directing air upwardly therethrough to enable a user or users to be supported by the airstream in simulating skydiving activities. The air containment unit is provided on a movable platform, such as a flatbed trailer, with all or substantially all components of the apparatus being mounted thereon or capable of being stored thereon in transit. The various elements, but in particular the air containment unit, are of a design that enables quick and efficient breakdown or disassembly of the components for transport with the apparatus on roads and highways, and which enables quick and efficient assembly of the components into an operable structure at successive locations.

Abstract: For the purpose of diminishing intake vortexes at jet engines with turbo-compressors of aircrafts, in particular during test runs, an apparatus is provided, which consists of a grating disposed near the ground below and directly in front of the engine inlet, which grating comprises short, approximately vertically extending wind tunnels.

Abstract: A method and apparatus for predicting flow over an object such as an air l or hydrofoil. The vortex strength for each of a plurality of vortex segments is obtained over an area of interest. The vortex segments are grouped into a series of square area defined by a series of boxes having different sizes. Initially a vortex strength is established for each of the smallest boxes and the coefficients then provide characteristic vortex strengths for a given box. The conversion of these vortex strengths into velocities is accomplished by directly computing the velocity of a given vorticity segment as influenced by all the vorticity segments in the box containing the given vorticity segment and the direct influence of each vortex segment in that box and any neighboring boxes. The influence of other vorticity segments outside the neighboring boxes is provided by using the influence of the average vortex strength of a given box or group of boxes.

Abstract: The present invention relates to measuring device for measuring a component f a force acting on a test body, such as a hydrofoil, positioned within a testing apparatus. The measuring device has a test body formed by a foil shaped center section and two adjacent end sections. Each end section is joined to the center section by a flexure member having sufficient stiffness so that there is negligible relative motion between the center section and the end sections as a fluid medium flows past the center section. At least one strain gauge is mounted to at least one flexure member to measure the forces acting on the center section. A method for measuring the load on a test body is also described.

Abstract: A free piston shot tube tunnel having a high speed valve for releasing the piston to start the piston shot. A further feature of the present invention is a free piston shock tube/tunnel having a high speed valve for releasing pressure from the compression tube into the shock tube.

Abstract: A portable wind tunnel features a tubular test section which has a constant cross-sectional area. The smaller end of a diffuser, which resembles a funnel, is attached to one end of the test section. The other end of the diffuser has a larger cross-sectional area. A flow generator, such as a fan, creates an airflow through the test section. The flow generator has an air inlet and an air outlet. A flow straightener is situated upstream from the air inlet of the flow generator normal to the direction of the airflow. The smaller end of a constrictor, which also resembles a funnel, is attached to the other end of the test section. The other end of the constrictor has a larger cross-sectional area.

Abstract: An environmental wind tunnel for producing air flow over an automotive vehicle includes a source of air under pressure and an elongated housing for receiving an automotive vehicle. The environmental wind tunnel has an upstream end coupled to the downstream end of the source of air under pressure, so that air is blown axially through the housing from its upstream end to its downstream end. The environmental wind tunnel also includes a large area ratio contraction with large area corner sections, large area duct work with a low angle diffuser, a large area fan, and acoustic treatments on the turning vanes, test chamber walls, and corner duct interior surfaces. In addition, in-flow acoustic absorption panels, and one or more flow conditioning screens may also be included in the environmental wind tunnel.

Abstract: A method for measuring drag forces acting on optical fibers and thin metal ires as a result of the influence of wind of varying force. Also a system for effecting such measurements, based on means for exposing a tightened fiber or wire to an essentially constant flow of air, while at an angle to such flow, means being provided for measuring forces acting on such fiber or wire.

Abstract: A wind tunnel having a plurality of walls surrounding a test section. The walls are provided with a plurality of longitudinal slots. A channel is formed behind each slot. Each channel contains a flexible channel bottom. The shape of the flexible channel bottom may be modified by adjustment devices. The influence of the walls on air flow is thereby decreased and made easier to compute. The influence of the walls on the testing of models is reduced, wind tunnel simulation is improved, and a more accurate and reliable computation of residual influences is provided.