Development of a flowmeter for simultaneous measurement of two velocity measurement components of a fluid to quantify volume flow and flow direction based on fiber optic temperature measurements in a geothermal borehole

For the precise design of geothermal plants, the quantification of currents in the aquifer is necessary, because the existing flow increases the heat reservoir. Therefore, in this project a thermal anemometer is investigated, which is based on proven fiber optic temperature measurements. A hybrid cable consisting of fiber optics and heating conductors is heated to exploit the fact that the temperature of the hybrid cable adjusts depending on the known heat flow and the unknown flow velocity. Empirical formulas or calibration rules can thus be used to quantify the velocity and with the help of a sophisticated probe concept, the flow direction shall be determined.