Measuring the flow rate in high-temperature gas-cooled reactors (HTGRs) is a challenge for traditional flow meters due to the high flow rate (10 - 15m/s at nominal operating conditions), high operating temperatures (> 700 ºC), and high neutron flux and gamma fields in the reactor core. In the present paper, we discuss developing a novel flow meter that can work under these extreme conditions. Oak Ridge national laboratory (ORNL) first proposed using sound to measure the flow in the reactor, more specifically, using a Kelvin-Helmholtz resonator to correlate the gas flow rate with vibration frequency. With the primary goal of developing a non-intrusive acoustic measurement technique, we propose an acoustic corrugated pipe as a candidate for the development of a novel gas flow meter. Experimental investigations on corrugated pipes have confirmed the dependence of the whistling frequency on the gas flow rate. Also, a tube-in-tube configuration is proposed for the flow meter prototype, which can help mitigate resonance between the system and the flow meter. Experimental investigation using the prototype has shown good independence from the piping system. Furthermore, URANS simulations have been performed and validated against the collected experimental data. Good agreement has been obtained, providing confidence that URANS models can adequately predict the characteristic curve (flow rate vs. frequency) of the corrugated pipe and can therefore be used to optimize the flow meter designs cost-effectively.