Abstract: A measurement system includes: a tube; a bluff body, situated in the lumen of the tube, for generating vortices in a flowing fluid such that a Karman vortex street is formed downstream of the bluff body; a vortex sensor, having a mechanical resonant frequency, for providing a vortex sensor signal which changes over time and contains a first component representing the vortex shedding frequency and which contains a second component representing the mechanical resonant frequency of the vortex sensor; and transducer electronics for evaluating the at least one vortex sensor signal and configured to do the following: to determine vortex frequency measurement values representing the shedding frequency using the first component and, if the first component is not present, not to provide flow parameter measurement values and to generate a message indicating the current flow speed is not lower than the current acoustic velocity of the flowing fluid.

Abstract: Disclosed is a tube configured to conduct a fluid flowing through the tube in a specified flow direction and for this purpose comprises a tube wall, which encloses a lumen of the tube, and an interference body, which is arranged within the tube but is nevertheless connected to the tube wall at an inner face of the tube wall facing the lumen. In the tube according to the present disclosure, the tube wall has a maximum wall thickness of more than 1 mm and at least two mutually spaced sub-segments with a respective wall thickness that deviates from said maximum wall thickness, wherein the sub-segment is positioned upstream of the interference body in the flow direction, and the sub-segment is positioned downstream of the sub-segment in the flow direction.

Abstract: A measurement system includes: a tube; a bluff body, situated in the lumen of the tube, for generating vortices in a flowing fluid such that a Kármán vortex street is formed downstream of the bluff body; a vortex sensor, having a mechanical resonant frequency, for providing a vortex sensor signal which changes over time and contains a first component representing the vortex shedding frequency and which contains a second component representing the mechanical resonant frequency of the vortex sensor; and transducer electronics for evaluating the at least one vortex sensor signal and configured to do the following: to determine vortex frequency measurement values representing the shedding frequency using the first component and, if the first component is not present, not to provide such flow parameter measurement values and to generate a message indicating the current flow speed is not lower than the current acoustic velocity of the flowing fluid.

Abstract: The tube is used to conduct a fluid flowing through the tube in a specified flow direction and for this purpose comprises a tube wall (110), which encloses a lumen (100*) of the tube, and an interference body (120), which is arranged within the tube but is nevertheless connected to the tube wall at an inner face of the tube wall facing the lumen. In the tube according to the invention, the tube wall has a maximum wall thickness (smax) of more than 1 mm and at least two mutually spaced sub-segments (100-1, 100-2) with a respective wall thickness (s110-1, s110-2) that deviates from said maximum wall thickness (smax), wherein the sub-segment (100-1) is positioned upstream of the interference body (120) in the flow direction, and the sub-segment (100-2) is positioned downstream of the sub-segment (100-1) in the flow direction.

Abstract: A flow measuring device operating on the vortex counter principle, comprises: a measuring tube; a blockage in the form of a bluff body in the measuring tube for bringing about a Karman vortex street with flow dependent vortex frequency; a first pressure fluctuation measuring arrangement for registering vortex related pressure fluctuations and for providing signals dependent on pressure fluctuations; a second pressure fluctuation measuring arrangement for registering vortex related pressure fluctuations and for providing signals dependent on pressure fluctuations. The first pressure fluctuation measuring arrangement is spaced in the longitudinal direction of the measuring tube from the second pressure fluctuation measuring arrangement.

Abstract: A flow measuring device operating on the vortex counter principle, comprises: a measuring tube; a blockage in the form of a bluff body in the measuring tube for bringing about a Karman vortex street with flow dependent vortex frequency; a first pressure fluctuation measuring arrangement for registering vortex related pressure fluctuations and for providing signals dependent on pressure fluctuations; a second pressure fluctuation measuring arrangement for registering vortex related pressure fluctuations and for providing signals dependent on pressure fluctuations. The first pressure fluctuation measuring arrangement is spaced in the longitudinal direction of the measuring tube from the second pressure fluctuation measuring arrangement.

Abstract: A method for determining mass flow of a two-phase medium flowing through a measuring tube of a vortex, flow measuring device. The measuring tube has in a measuring cross section at least one bluff body for producing vortices. By sensor registering of the produced vortices, a flow velocity of the medium in the region of the measuring cross section is determined. In the method, the density of the medium in the region of the measuring cross section is determined from the specific, total enthalpy of the medium in the region of the measuring cross section, from the flow velocity of the medium in the region of the measuring cross section, from a static pressure of the medium in the region of the measuring cross section and from the static temperature of the medium in the region of the measuring cross section. Additionally, the mass flow is determined from the determined flow velocity, the determined density and a flow cross section of the medium in the region of the measuring cross section.

Abstract: A vortex flow measuring device as well as a method for determining by means of a vortex, flow measuring a device, which has a bluff body protruding into the flowing medium and a vortex sensor, the mass flow ratio (x) of an at least at times two- or multiphase medium flowing in a measuring tube and having a gaseous first phase flowing with a first mass flow rate {dot over (m)}G and a liquid second phase flowing with a second mass flow rate {dot over (m)}L.

Abstract: A method for determining mass flow of a two-phase medium flowing through a measuring tube of a vortex, flow measuring device. The measuring tube has in a measuring cross section at least one bluff body for producing vortices. By sensor registering of the produced vortices, a flow velocity of the medium in the region of the measuring cross section is determined. In the method, the density of the medium in the region of the measuring cross section is determined from the specific, total enthalpy of the medium in the region of the measuring cross section, from the flow velocity of the medium in the region of the measuring cross section, from a static pressure of the medium in the region of the measuring cross section and from the static temperature of the medium in the region of the measuring cross section. Additionally, the mass flow is determined from the determined flow velocity, the determined density and a flow cross section of the medium in the region of the measuring cross section.