Abstract: A method of overcoming the problems of measuring the exhaust flow during pulsating and reversing flow by placing a “box” in series within a few feet of the connecting pipe to serve as a filter. The box is constructed with soft expandable sides, so it can expand with the pressure pulsations and then contract, creating a very smooth flow that can be measured with a measuring device at the exit of the flow from the box.

Abstract: A method of overcoming the problems of measuring the exhaust flow from a vehicle engine, which flow is pulsating and reversing, making it difficult to accurately measure. An amount of flow is added to the exhaust flow so that the combined amount of flow exceeds the reversals, and therefore the flow through the primary measuring device is raised a sufficient amount so that the measured flow of the exhaust is always positive. The source of the added flow can be by diverting some of the exhaust flow itself downstream from the measurement device and reintroducing it upstream of the measurement device. In the alternative, the added flow can be from a source external to the exhaust flow.

Abstract: A narrow generator plate (10) is immersed parallel to the direction of flow of a fluid stream (14) for generating Karman vortices. In its various embodiments the generator plate (10) is provided with surface disruption (52) for generating boundary-layer turbulence in the fluid stream in order to eliminate the occurrence of a boundary-layer transition region which would otherwise occur for a range of fluid flow velocities of interest.

Abstract: A narrow generator plate (10) is immersed parallel to the direction of flow of a fluid stream (14) for generating Karman vortices (54). In one embodiment the generator plate (10) has a shedding section wherein an aperture (26) intersects side surfaces (20) of the generator plate (10) at shedding corners (32). A further embodiment includes a generator member (36) mounted on a leading edge (16) of a generator plate (10) and oriented upstream into the fluid stream.

Abstract: This disclosure describes a method and apparatus for using a single sensor to determine the relative velocity between an object and a fluid stream, the average temperature, pressure and/or density of the fluid stream, and thereby the mass flow of the fluid stream. Select properties of a signal, such as a sonic signal, directed through a vortex street are detected using modifications of existing single sensor vortex volumetric flowmeter methods and apparatus. The modifications facilitate the measurement of mass flow by measurements of the relative energy of the signal and the temperature of the fluid as ascertained from the time delay in signal passage from a signal directing means (43) to a signal receiving means (45).