Preliminary Evidence of Sound Amplification of Turbulent Noise due to Latent Heat

Infrasound is sound that is below the human threshold of hearing. It has been observed that tornadoes and tornadic storms produce infrasound signatures that relate to the characteristics and formation of the tornado. Detecting infrasound signatures from tornadic storms could be a new method for tornado detection, especially in areas with hilly terrain where line-of-sight methods such as radar are not as effective. However, to effectively use this method of detection, the physical mechanisms responsible for the infrasound signature must be determined. It has been theorized that a thermodynamic effect related to water condensation within the tornado is responsible for amplifying the infrasound signature. An experimental method to create this thermodynamic effect within a small turbulent jet has been developed. Microphones were positioned to measure the sound propagating from the turbulent jet. A comparative analysis of the sound pressure levels from a dry and saturated jet with and without external cooling was performed. This presentation will show the preliminary findings from the experimental setup that indicate that the theorized effect could be present.