It is described a method for determining a characteristic of air flow close to a surface of a rotating blade of a wind turbine, the method including: measuring at least one value of the temperature of air close to the surface of the blade; and deriving the characteristic of the air flow based on the temperature value.

The present application generally relates to fluid flow detection apparatuses and methods for detecting a water leak in a pipe system of a building. A method may: determine that a low flow is present, if absolute values of temperature differences between ambient and pipe temperatures of respective samples of a first monitoring period are above a difference threshold; and perform a high flow test by estimating a temperature profile of water entering the pipe, based on identifying at least one temperature difference maximum of a second monitoring period, wherein each said difference maxima is a maximum temperature difference between ambient and pipe temperatures of a received sample, and determining that a high flow is present by detecting, based on the received pipe temperatures of the second monitoring period, if the pipe temperature is approaching the estimated water temperature profile.

A method of electronically deriving a conclusion of a condition of slurry flow in a non-vertical conduit having a conduit wall and which contains a slurry to flow or flowing along the conduit is provided.

A flow detector for detecting flow rates of fluid in pipes by measuring the temperature of the pipe and the ambient temperature and determining from the signals whether there is a flow in the pipe, by the shape of the temperature signals without providing any heat input to the pipe or fluid.

A method of deriving a conclusion of the condition of slurry flow in a non-vertical conduit includes artificially generating a first locally heated spot on an interior surface of the conduit at the invert of the conduit and artificially generating a second locally heated spot on the interior surface of the conduit at a location angularly spaced from the first heated spot at an angular spacing of at least 90. The temperatures of the heated spots are measured, obtaining first and second temperature values T1, T2. Electronically generated signals carrying the values T1, T2 are communicated to an electronic computing device. The computing device automatically calculates a first temperature difference T1 minus T2 and automatically derives a conclusion of the condition of slurry flow prevailing in the conduit based on the relationship between the value of the first temperature difference and a first reference parameter.

Disclosed herein is a wind measuring system including a first flow sensor and plural second flow sensors. The first flow sensor and the plural second flow sensors each include a microheater including a board, an insulating film, and a heater. The board includes a first principal surface and a second principal surface. The board has defined therein an opening portion passing through the board along a direction from the first principal surface toward the second principal surface. The insulating film includes a peripheral portion disposed on the first principal surface, a central portion having the heater disposed thereon, and a connection portion extending from the central portion to be connected to the peripheral portion to support the central portion over the opening portion. The first flow sensor and the plural second flow sensors each output a signal that varies according to a change in electrical resistance value of the heater.

The invention relates to a method of measuring turbulence in a high temperature fluid flow, comprising: applying different levels of cooling at different times to a region of a substrate in the high temperature fluid flow; and/or applying different levels of cooling at the same time to different regions of a substrate in the high temperature fluid flow and/or to regions on different substrates in the high temperature fluid flow, wherein the method further comprises: measuring fluctuations in the temperature of the region or regions of the substrate or substrates at each of the different levels of cooling; and using the measured fluctuations to determining an amount of turbulence in the high temperature fluid flow and/or the size of temperature fluctuations in the high temperature fluid flow.

A wind direction meter has the following plurality of sensors and a control unit. Each sensor has a first surface and has first and second interlayer connection members made of different metals or semiconductors. Further, the wind direction meter includes a thermoelectric conversion element which generates an electrical output when a temperature difference occurs between first ends and second ends of the respective first and second interlayer connection members. The sensor generates an electric output when the surrounding air, whose temperature has been changed by a heater, is moved by the wind to produce a temperature difference between the first ends and the second ends of the first and second interlayer connection members. The control unit calculates the direction of the wind on the basis of the difference in output. Thus, the wind direction of a weak wind can be detected with the wind direction meter.

The present application generally relates to fluid flow detection apparatuses and methods for detecting a water leak in a pipe system of a building. A method may: determine that a low flow is present, if absolute values of temperature differences between ambient and pipe temperatures of respective samples of a first monitoring period are above a difference threshold; and perform a high flow test by estimating a temperature profile of water entering the pipe, based on identifying at least one temperature difference maximum of a second monitoring period, wherein each said difference maxima is a maximum temperature difference between ambient and pipe temperatures of a received sample, and determining that a high flow is present by detecting, based on the received pipe temperatures of the second monitoring period, if the pipe temperature is approaching the estimated water temperature profile.

A flow detector for detecting flow rates of fluid in pipes by measuring the temperature of the pipe and the ambient temperature and determining from the signals whether there is a flow in the pipe, by the shape of the temperature signals without providing any heat input to the pipe or fluid.