Development of a thermoacoustic travelling-wave engine

作者：Lawn Chris^*

来源：Proceedings of the Institution of Mechanical Engineers - Part A: Journal of Power and Energy , 2013, 227(7): 783-802.

DOI：10.1177/0957650913498080

• Thermoacoustic engine
• radiative heat exchange
• linear alternator
• mesh regenerator

The objective of the study is to develop a thermoacoustic generator of 100W of electricity that is powered by the heat of a wood-burning stove, which is cheap to produce and easy to maintain. Attention has been concentrated on an unpressurised, air-filled acoustic duct in a looped configuration designed to generate a travelling-wave. The heat transfer to the hot-end of the acoustic regenerator in this loop is through a steel plate that forms the top of the combustion chamber. The regenerator is of the woven-steel mesh design, and the acoustic losses and conductivity of two grades of this material have been determined outside the loop. The regenerator and heat exchangers were first tested with acoustic oscillations produced by a pair of sub-woofers. These results, and those from a simple theory for regenerator efficiency, are described. With both meshes and various configurations of loop, spontaneous oscillations with acoustic pressures up to 2500Pa have been generated in the range 70-90Hz. These have driven a linear alternator built by Nottingham University to produce 9.6W. Numerous attempts to improve on this performance, involving tuning the loop and the alternator, are discussed. Mathematical models of the alternator, the loop thermoacoustics and the interaction with the radiant heat exchange from the flame are shown to describe the observations, and these will guide future development.

• 出版日期2013-11