Cetiner, Mustafa S. | Search NASA

DOE OSTI2024

Ultrasonic waveguide for improved ultrasonic thermometry

An improved ultrasonic waveguide for an ultrasonic thermometry system is provided. The waveguide includes a series of sensing zones, each of which is tuned to a specific narrow frequency band. The waveguide is acoustically coupled to a transducer, which launches a longitudinal elastic wave of desired waveform and frequency. The wave propagates down the waveguide, and is reflected from the sensing zone that is tuned to that frequency. Each sensing zone is designed to be highly reflective to a narrow frequency band while being transparent to other frequencies.

Cetiner, Nesrin O.↗

DOE OSTI2023

Method and system to measure gas flow

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.

Cetiner, Mustafa S.↗