Apparatus for measuring the velocity of a fluid flow

An apparatus for measuring flow velocity of a fluid flow, comprising:

• a high voltage source;
• an emitter electrode connected to the high voltage source, wherein the emitter electrode is tangentially arranged at the fluid flow, and wherein electric charge carriers are emitted into the fluid flow and an emitter current flows through the emitter electrode;
• a sensor electrode disposed at a second location of the fluid flow, wherein a first portion of the emitted charge carriers is drained by the sensor electrode and a sensor current flows through the sensor electrode;
• a counter electrode that is insulated from the emitter electrode, wherein a second portion of the emitted charge carriers flows off via the counter electrode;
• a measuring device that measures the sensor current and the emitter current, wherein the measuring device provides a measured value of the sensor current and a measured value of the emitter current;
• and
• a computing device that computes the flow velocity of the fluid flow, wherein the computing device computes the flow velocity from the ratio between the measured value of the sensor current and the measured value of the emitter current, the flow velocity of the fluid flow being computed according to a proportional relationship to the ratio between the measured value of the sensor current and the measured value of the emitter current.