Synthetic jet cooling using asymmetric acoustic dipoles

In two earlier papers the principles and experimental results have been discussed for a typical embodiment of synthetic jet cooling technology: an acoustic dipole cooler comprised of a standard loudspeaker in a housing provided with two pipes. The current paper shows experimental and numerical results for another type: the asymmetric dipole. Basically, this type consists of a loudspeaker with a minimal volume attached to it with one or more holes with or without pipes. Results for driving power and noise are presented for a number of actuators covering a large parameter space: frequency, pipe dimensions and driving voltage were varied over a large range. A relatively simple acoustic model extended to include separation losses matched the experimental results very well. The results indicate promising heat transfer performance with minimal noise combined with a large degree of freedom.