Abstract
In thermoacoustic devices, an acoustic wave interacts with stacks and heat exchangers in a resonator. Placing such internal structures, in what is
essentially an oscillatory flow, produces complex flow phenomena around their extremities due to the introduction of cross-sectional discontinuities. One of the
simplest geometries of stacks and heat exchangers can be imagined as a series of parallel plates; velocity profiles in the channels in between are disturbed by the entrance effects.
In this work, particle image velocimetry (PIV) is used to investigate the flow structure in the “entrance region”. Velocity profiles of the oscillating air flow
within the channel of a parallel-plate stack, placed in a standing wave resonator, were measured as a function of phase and distance from the stack end. Using the data obtained, this work attempts to quantify an “entrance length” (by analogy with existing fluid mechanical definitions). Its estimations are carried out over the half cycle of an oscillation period, when the working gas is known to flow into the stack. This is followed by the discussion of future uses of the methodology presented
essentially an oscillatory flow, produces complex flow phenomena around their extremities due to the introduction of cross-sectional discontinuities. One of the
simplest geometries of stacks and heat exchangers can be imagined as a series of parallel plates; velocity profiles in the channels in between are disturbed by the entrance effects.
In this work, particle image velocimetry (PIV) is used to investigate the flow structure in the “entrance region”. Velocity profiles of the oscillating air flow
within the channel of a parallel-plate stack, placed in a standing wave resonator, were measured as a function of phase and distance from the stack end. Using the data obtained, this work attempts to quantify an “entrance length” (by analogy with existing fluid mechanical definitions). Its estimations are carried out over the half cycle of an oscillation period, when the working gas is known to flow into the stack. This is followed by the discussion of future uses of the methodology presented
Original language | English |
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Title of host publication | Proceedings of the International Congress on Ultrasonics |
Subtitle of host publication | Vienna, April 9-13 |
Number of pages | 4 |
Publication status | Published - 9 Apr 2007 |
Externally published | Yes |