Investigation of a Heat Driven Thermoacoustic Prime Mover
Abstract
The goal of this thesis is to investigate the work output of a heat driven thermoacoustic prime mover. The experimental approach was to measure the frequency response of both a simple resonant tube and a prime mover for a variety of values of mean gas pressure and applied temperature different across the prime mover stack. A least squares fit to the frequency response yields the quality factor which can be compared to predictions based on a short stack, boundary layer approximation theory. The results are reported of measurements made on the lowest three modes of the prime mover in helium for mean gas pressures between approximately 170 kPa and 500 kPa and the applied temperature differences between zero and onset. The signal waveforms of the sound generated by the prime mover above onset at a mean gas pressure of 308 kPa are also reported. Results for the resonant tube have at most 3% difference with theory. For the prime mover, the measurements generally agree with predictions for the fundamental mode except close to onset. This agreement between measured and predicted results worsens with decreasing mean gas pressure. Agreement is poor for the second and third modes for all pressures used. Finally, the sound generated by the prime mover above onset is highly distorted, and the distortion becomes more serve as the temperature difference increases. The peak positive pressure amplitude of this signal at temperature difference of 325 C, 368 C and 453 C are 1.1%, 4.4% and 7.9% of mean gas pressure, respectively. Keywords: Acoustics, Thermoacoustics, Thermoacoustic heat transports.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1989
- Accession Number
- ADA223928
Entities
People
- Hsiao-tseng Lin
Organizations
- Naval Postgraduate School