Abstract: A passive acoustic gas wave generator of a gas pipe and a tube-in-tube construction thereof are presented. The passive acoustic gas wave generator is a component of a larger acoustic gas flow meter assembly. The tube-in-tube construction eases installation in application and use, and particularly in applications exhibiting harsh and extreme conditions such as in nuclear power reactors. In an implementation, the passive acoustic gas wave generator has a tube body and a support structure. The tube body has a tube gas flow passage and a multitude of corrugations residing at an inner surface thereof. The corrugations induce a phenomenon known-as vortex shedding within a gas flow stream passing through the tube gas flow passage. The support structure centrally locates the tube gas flow passage relative to a pipe gas flow passage of the gas pipe.

Abstract: A system for measuring gas flow generally including a passive acoustic wave generator disposed in a gas flow stream to passively generate an audio signal through vortex shedding, a sound capturing instrument disposed outside the gas stream to produce an electrical signal representative of the acoustic signal, a temperature sensor to obtain temperature measurements indicative of the temperature of the gas flow stream and a control system for determining the gas flow, such as velocity or flow rate, as a function of the acquired acoustic and temperature measurements. The acoustic wave generator includes a corrugated flow channel whose geometric design is so tuned to generate an acoustic emission whose frequency signature varies as a function of the gas flow velocity. The control system may acquires time-domain acoustic data, and process that data to obtain a frequency-domain representation from which gas velocity or gas flow rate can be determined.

Abstract: A system for measuring gas flow generally including a passive acoustic wave generator disposed in a gas flow stream to passively generate an audio signal through vortex shedding, a sound capturing instrument disposed outside the gas stream to produce an electrical signal representative of the acoustic signal, a temperature sensor to obtain temperature measurements indicative of the temperature of the gas flow stream and a control system for determining the gas flow, such as velocity or flow rate, as a function of the acquired acoustic and temperature measurements. The acoustic wave generator includes a corrugated flow channel whose geometric design is so tuned to generate an acoustic emission whose frequency signature varies as a function of the gas flow velocity. The control system may acquires time-domain acoustic data, and process that data to obtain a frequency-domain representation from which gas velocity or gas flow rate can be determined.