Abstract: Wind tunnel having a free jet test section for simulating wind direction fluctuations, principally for the investigation of vehicles, equipped with a nozzle which can be rotated when the wind tunnel is operating, in order to alter the wind flow direction, in which arrangement the nozzle comprises a stationary part and a rotatable front part and the nozzle front part is surrounded by a cylinder surface which is sealed off in the manner of a plug in the end wall of the nozzle prechamber in relation to the test chamber; within the nozzle prechamber, which surrounds the nozzle, a compensating flow can take place upon rotation of the nozzle front part, so that the quality of the jet flow of the wind tunnel is, if at all, only barely noticeably impaired by the rotational movement. In order to investigate flow-acoustic problems with a varying wind direction, the wind tunnel can be equipped with sound deadening and sound attenuating devices as well as an absorbing lining.

Abstract: A method and device for acoustic flow measurement of the flow velocity of gases is disclosed. An acoustic signal is transmitted into the measurement pipe and, under ideal working conditions, the signals are detected both upstream and downstream by means of two sound detectors mounted at a certain distance from each other within the measurement pipe, the flow velocity of the gas in the measurement pipe being determined by means of correlation of the sound signals. A standardized sound speed in the medium at rest is stored in memory, and whenever one of either the upstream or downstream travel times cannot be measured due to a disturbance, the flow velocity is computed from a single travel time, either downstream or upstream, and by means of the sound speed at rest stored in memory.

Abstract: A capacitance type electromagnetic flowmeter which is capable of measuring flow rates of fluid without being affected by the flow velocity distribution. When the flow tube of the flowmeter is an open conduit, the measurement is made without being affected by variations in the liquid level. The flowmeter comprises a flow tube insulated at least on an inner surface thereof; an exciting means for applying a magnetic field to the fluid, and a pair of detecting electrodes disposed in the flow tube, which are electrically insulated from the fluid and extend at right angles to the flow tube axis and magnetic field. The length of the electrodes is proportional to the cosine of an angle between a line normal to the wall of the flow tube and an axis perpendicular to both axes of the flow tube and magnetic field. Where a conduit is used, the liquid has a free surface, and currents produced from the detecting electrodes are converted by a current-to-voltage converter into voltage signals.

Abstract: An object of spherical shape is disposed in such a way that it changes the peed of any flow of two-dimensionally varying direction to the same extent. The dynamic pressure on the object, relative to the ambient, is so measured that there exists a unique and theoretically determined relation between the pressure and the speed of approaching flow.

Abstract: The present disclosure is directed to a method and apparatus for removing a small sized sample from a very large tanker container. The tank is closed, a valve is mounted in the deck which closes the tank, and the present apparatus attaches to that valve. This defines an open and close passage into the tank. A sample container on a measured steel tape is lowered through the passage into the tank and retrieves a measured sample. Sample container is removed outside the tank in a sample transfer mechanism. The sample transfer mechanism incorporates a container filling head or assembly which features a pair of needles which penetrate the septum on the mouth of a half liter or liter container which can be carried to a test facility after filling. Two needles are used, one to introduce the liquid into the container and the other to vent the container fumes or any over flow, and the vented fumes and over flow are directed to a charcoal carbon filled filter.

Abstract: A multi-axis force platform for determining forces and moments exerted on the platform along x, y and z axes includes at least one multi-axis spring. The multi-axis spring includes a block of rigid material through which a pattern of slots pass through to form a series of deflectable beams separated from each other by the slots. The deflectable beams surround an interior region of the spring and elastically couple the interior region of the spring to an outer region of the spring such that the interior region can deflect relative to the outer region along x, y and z axes when subjected to a load. One or more magnetic sensors are positioned within the interior region of the spring for sensing loads exerted on the spring.

Abstract: An Optical Time Slot Interchange (OTSI) Apparatus that has relatively low optical fiber requirements and good attenuation and signal-to-noise characteristics. This OTSI uses parallel feedback (PFB) to provide the delays. This PFB OTSI can be implemented with an n.times.n optical crossbar switch. The PFB OTSI is conditionally, i.e., rearrangeably, non-blocking for 16.times.16 crossbar switch implementations if a controller using the control method of the invention is also included.

Abstract: The present invention is an improved ice sensor which is particularly effective in measuring and quantifying non-uniform, heterogeneous ice typically found on aircraft leading edges and top wing surfaces. In one embodiment, the ice sensor comprises a plurality of surface mounted capacitive sensors, each having a different electrode spacing. These sensors measure ice thickness by measuring the changes in capacitance of the flush electrode elements due to the presence of ice or water. Electronic guarding techniques are employed to minimize baseline and parasitic capacitances so as to decrease the noise level and thus increase the signal to noise ratio. Importantly, the use of guard electrodes for selective capacitive sensors also enables distributed capacitive measurements to be made over large or complex areas, independent of temperature or location, due to the capability of manipulating the electric field lines associated with the capacitive sensors.

Abstract: A sensor measures an unknown pressure having to a sensitivity on the order of 1 micro-torr. The sensor includes two 10 micro-torr sensitivity capacitance manometers which each receive the unknown pressure. The capacitance manometers are positioned about a common axis around a common pressure chamber that receives the unknown pressure so that the flexible diaphragms of each of the capacitance manometers simultaneously deform either outwardly or inwardly from the common pressure chamber in response to changes in pressure. When a vibrational or gravitational force is applied to the sensor, one flexible diaphragm deforms outwardly away from the common pressure chamber and the other deforms inwardly towards the common pressure chamber. Hence, changes in pressure cause each of the capacitance manometers to produce a like change in their output signal; however, vibrational or gravitational forces produce an opposite change in their output signal.

Abstract: A mass flowmeter comprises a nonvibrating conduit providing a flow passage divided into two parallel and equal subpassages by a planar member with the leading and trailing edges secured to the wall of the flow passage, wherein the planar member is torsionally vibrated about the central axis thereof substantially coinciding with the center line of the flow passage, and a pair of vibration sensors detecting the torsional vibration of the planar member respectively at two different cross sections of the flow passage, wherein the mass flow rate of media moving through the flow passage is determined as a function of a phase angle difference between two alternating electrical signals respectively provided by the pair of vibration sensors.