Qualitative analysis of mode transitions in bottle-shaped resonators with waterfall plots

ORAL

Abstract

A closed bottle-shaped resonator consists of a coupled acoustic system with the neck behaving as a quarter-wave resonator and the cavity as a half-wave resonator. Such a system gives rise to overtones that are not harmonic of the fundamental and could be used as a thermal sensor. A thermoacoustic stack subject to a temperature gradient can generate self-sustained oscillations within the bottle. Mode transitions were previously observed to occur at the same position within a few millimeters when a piston controlled with a translation stage was moved up or down with a manual control to adjust the cavity length. The dominant mode was recorded using a power spectrum of the signal measured with a pressure sensor. In this study, the piston motion is automated and eight neck/cavity combinations were tested at three different piston speeds and at various input powers. The input powers were adjusted to just above thermoacoustic onset and not to exceed thermal limits of the materials used. Waterfall plots allow the visualization of the time evolution of the power spectrum where intensity is plotted both as a function of time and frequency. Qualitatively, the transitions occur at the same place within the cavity after a threshold input power is reached.

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Authors

  • Bonnie Andersen

    Utah Valley Unversity, Utah Valley University

  • Josh Dimond

    Utah Valley University

  • Colin Roberts

    High Precision Devices, Boulder, CO, Raytheon, Tucson, AZ, Seagate Technology, Minneapolis, MN, Ball Aerospace (retired), Bloomfield, CO, New Mexico State University, Brigham Young University, Colorado State University, Heinrich-Heine-Universitat Dusseldorf, National Security Technologies, Universidad de Buenos Aires, Colorado State Univ, Colorado College, Utah State University, Advisor, Material Physics Group, Utah State University, Box Elder Innovations, LLC, JILA and Department of Physics, CU Boulder, JILA and Department of Mathematics, CU Boulder, Colorado State University, Fort Collins, Colorado 80523, USA, JILA, NIST and the University of Colorado, Boulder, NIST, University of Colorado / NIST, University of Colorado/JILA, Colorado Sch of Mines, Colorado School of Mines, Southwestern Indian Polytechnic Institute, UC-Berkeley, Colorado State University, Fort Collins, CO, Wroclaw University of Science and Technology, Wroclaw, Poland, JILA, University of Colorado and NIST, Harvard University and Harvard-MIT Center for Ultracold Atoms, Univ of Colorado - Boulder, USAFA, Univ of Denver, Boyce Research Initiatives and Educational Foundation, Brilliant Sky Observatory, San Diego Mesa College, Utah Valley University, University of Colorado Boulder, Brigham Young Univ - Provo, Oak Ridge National Laboratory, University of Sherbrooke, NIST Boulder, Universidad Complutense de Madrid, Electrical and Computer Engineering Department, Colorado State University, Fort Collins, Co 80525, Lawrence Livermore National Lab. (United States), Physics Department, Colorado State University, Fort Collins, Co 80525, JILA, Department of Physics, University of Colorado Boulder, Los Alamos National Laboratory, University of Alabama, University of Wyoming, University of Guelph, University of Guelph, Canadian Light source

  • Colin Roberts

    High Precision Devices, Boulder, CO, Raytheon, Tucson, AZ, Seagate Technology, Minneapolis, MN, Ball Aerospace (retired), Bloomfield, CO, New Mexico State University, Brigham Young University, Colorado State University, Heinrich-Heine-Universitat Dusseldorf, National Security Technologies, Universidad de Buenos Aires, Colorado State Univ, Colorado College, Utah State University, Advisor, Material Physics Group, Utah State University, Box Elder Innovations, LLC, JILA and Department of Physics, CU Boulder, JILA and Department of Mathematics, CU Boulder, Colorado State University, Fort Collins, Colorado 80523, USA, JILA, NIST and the University of Colorado, Boulder, NIST, University of Colorado / NIST, University of Colorado/JILA, Colorado Sch of Mines, Colorado School of Mines, Southwestern Indian Polytechnic Institute, UC-Berkeley, Colorado State University, Fort Collins, CO, Wroclaw University of Science and Technology, Wroclaw, Poland, JILA, University of Colorado and NIST, Harvard University and Harvard-MIT Center for Ultracold Atoms, Univ of Colorado - Boulder, USAFA, Univ of Denver, Boyce Research Initiatives and Educational Foundation, Brilliant Sky Observatory, San Diego Mesa College, Utah Valley University, University of Colorado Boulder, Brigham Young Univ - Provo, Oak Ridge National Laboratory, University of Sherbrooke, NIST Boulder, Universidad Complutense de Madrid, Electrical and Computer Engineering Department, Colorado State University, Fort Collins, Co 80525, Lawrence Livermore National Lab. (United States), Physics Department, Colorado State University, Fort Collins, Co 80525, JILA, Department of Physics, University of Colorado Boulder, Los Alamos National Laboratory, University of Alabama, University of Wyoming, University of Guelph, University of Guelph, Canadian Light source