A wind turbine for generating electric energy including a tower equipped with rotatable nacelle with rotor which is rotatable about a horizontal rotational axis and which comprises an electric generator. The wind turbine additionally comprises a device for determining flow direction and speed of the wind and a device for or regulating the alignment of the rotor against the wind. The device for determining speed and flow direction comprises pair of receiving antennas, for obtaining electric signals using electrically influenced particles, molecules carried by the wind and are supplied to a correlation measurement device. Here, the time needed by the electrically influenced particles/molecules to traverse the distance between the receiving antennas of a pair of receiving antennas is determined. Subsequently, speed and flow direction of the wind are calculated in a computing device and are supplied to the device for controlling or regulating the alignment of the rotor.

The flow rate of light scattering fluid is measured more easily and at a higher speed. A flow rate measuring method according to the present disclosure includes: generating two or more speckle images by continually imaging light scattering fluid to be measured, while defining time shorter than spatial correlation disappearance time corresponding to time in which spatial correlation between speckle patterns generated by the light scattering fluid disappears as exposure time, at a time interval shorter than the spatial correlation disappearance time; and calculating direction and speed of flow of the light scattering fluid from time variation of the speckle patterns between the two or more speckle images, in which the speckle images are imaged by using an imaging device mounted with an area sensor and a pixel group of a part of the area sensor or by using an imaging device mounted with a line sensor.

The flow rate of light scattering fluid is measured more easily and at a higher speed. A flow rate measuring method according to the present disclosure includes: generating two or more speckle images by continually imaging light scattering fluid to be measured, while defining time shorter than spatial correlation disappearance time corresponding to time in which spatial correlation between speckle patterns generated by the light scattering fluid disappears as exposure time, at a time interval shorter than the spatial correlation disappearance time; and calculating direction and speed of flow of the light scattering fluid from time variation of the speckle patterns between the two or more speckle images, in which the speckle images are imaged by using an imaging device mounted with an area sensor and a pixel group of a part of the area sensor or by using an imaging device mounted with a line sensor.

A fluid measurement system includes a first sensor and a second sensor disposed on a same pipe and spaced apart from each other by a predetermined distance; and a measurement controller configured to calculate a flow velocity of a fluid flowing through the pipe based on first output that is output from the first sensor and second output that is output from the second sensor. The measurement controller performs a process including (a) comparing the first output and the second output in a first period of time so as to repeatedly calculate a first time difference between the first output and the second output while shifting the first period of time, (b) calculating a second time difference based on a frequency of occurrence of a plurality of first time differences each calculated in the first period of time, and (c) calculating the flow velocity based on the second time difference.

A fluid measurement system includes a first sensor and a second sensor disposed on a same pipe and spaced apart from each other by a predetermined distance; and a measurement controller configured to calculate a flow velocity of a fluid flowing through the pipe based on first output that is output from the first sensor and second output that is output from the second sensor. The measurement controller performs a process including (a) comparing the first output and the second output in a first period of time so as to repeatedly calculate a first time difference between the first output and the second output while shifting the first period of time, (b) calculating a second time difference based on a frequency of occurrence of a plurality of first time differences each calculated in the first period of time, and (c) calculating the flow velocity based on the second time difference.

A wind turbine for generating electric energy including a tower equipped with rotatable nacelle with rotor which is rotatable about a horizontal rotational axis and which comprises an electric generator. The wind turbine additionally comprises a device for determining flow direction and speed of the wind and a device for or regulating the alignment of the rotor against the wind. The device for determining speed and flow direction comprises pair of receiving antennas, for obtaining electric signals using electrically influenced particles, molecules carried by the wind and are supplied to a correlation measurement device. Here, the time needed by the electrically influenced particles/molecules to traverse the distance between the receiving antennas of a pair of receiving antennas is determined. Subsequently, speed and flow direction of the wind are calculated in a computing device and are supplied to the device for controlling or regulating the alignment of the rotor.

A wind turbine for generating electric energy including a tower equipped with rotatable nacelle with rotor which is rotatable about a horizontal rotational axis and which comprises an electric generator. The wind turbine additionally comprises a device for determining flow direction and speed of the wind and a device for or regulating the alignment of the rotor against the wind. The device for determining speed and flow direction comprises pair of receiving antennas, for obtaining electric signals using electrically influenced particles, molecules carried by the wind and are supplied to a correlation measurement device. Here, the time needed by the electrically influenced particles/molecules to traverse the distance between the receiving antennas of a pair of receiving antennas is determined. Subsequently, speed and flow direction of the wind are calculated in a computing device and are supplied to the device for controlling or regulating the alignment of the rotor.

An optically based combustion off-gas stream velocity sensor assembly is provided for detecting in real-time off-gas flow velocity and/or volume as it moves through a flue duct. The sensor assembly includes two paired coherent light emitters and optic sensors, positioned in a spaced orientation in the flow path direction. The light emitter/optic sensor pairs operate to emit and detect across the off-gas stream coherent light beam energy having a wavelength component corresponding to an absorption profile of an off-gas species component. The detection of non-absorbed portions of the emitted beam is used to identify and detect the movement of a flow species signature at different locations along the flue duct.

An optically based combustion off-gas stream velocity sensor assembly is provided for detecting in real-time off-gas flow velocity and/or volume as it moves through a flue duct. The sensor assembly includes two paired coherent light emitters and optic sensors, positioned in a spaced orientation in the flow path direction. The light emitter/optic sensor pairs operate to emit and detect across the off-gas stream coherent light beam energy having a wavelength component corresponding to an absorption profile of an off-gas species component. The detection of non-absorbed portions of the emitted beam is used to identify and detect the movement of a flow species signature at different locations along the flue duct.

The flow rate of light scattering fluid is measured more easily and at a higher speed.

A flow rate measuring method according to the present disclosure includes: generating two or more speckle images by continually imaging light scattering fluid to be measured, while defining time shorter than spatial correlation disappearance time corresponding to time in which spatial correlation between speckle patterns generated by the light scattering fluid disappears as exposure time, at a time interval shorter than the spatial correlation disappearance time; and calculating direction and speed of flow of the light scattering fluid from time variation of the speckle patterns between the two or more speckle images, in which the speckle images are imaged by using an imaging device mounted with an area sensor and a pixel group of a part of the area sensor or by using an imaging device mounted with a line sensor.