Parameter analysis in thermoacoustic mixing

Sammanfattning

Thermoacoustic mixing can be a method of enhancing mixing in micro channels by utilizing temperature differences in fluids and applying an acoustic field. The main goal of the project was to build a functional thermal setup, to investigate the significance of input parameters, and to find the optimal parameters in order to achieve the best mixing enhancement. The project was executed at the department of Biomedical engineering at LTH, and was done by first building a setup to generate the thermal gradient outside of the microfluidic device, secondly by performing an analysis of the efficiency of the setup, trying different combinations of input parameters to find the optimal setup and finally a parameter analysis. The results from the efficiency analysis showed that the setup had a weak thermal retention, which resulted in unstable data when investigating thermal parameters. Generating the acoustic field along the channel height showed no significant effect on the fluids, which was unexpected. The parameter analysis showed that voltage on the sound transducers had more significant effect in mixing enhancement. Changing the fluid flow ratio from an equal distribution resulted in a decrease in mixing efficiency. From these results, it was concluded that the amount of acoustic energy deposited onto the fluids is likely to be of highest significance, however, no significance could be found for the thermal parameters, considering the inefficiency of the setup. Flow ratios outside of equal distribution showed drastic decrease in performance, therefore retaining equal inlet volumetric flow-rates is advisable.