%0 Journal Article
%T A Comparative Study of Nozzle/Diffuser Micropumps with Novel Valves
%A Kai-Shing Yang
%A Tzu-Feng Chao
%A Ing Youn Chen
%A Chi-Chuan Wang
%A Jin-Cherng Shyu
%J Molecules
%D 2012
%I MDPI AG
%R 10.3390/molecules17022178
%X This study conducts an experimental study concerning the improvement of nozzle/diffuser micropump design using some novel no-moving-part valves. A total of three micropumps, including two enhancement structures having two-fin or obstacle structure and one conventional micro nozzle/diffuser design, are made and tested in this study. It is found that dramatic increase of the pressure drops across the designed micro nozzles/diffusers are seen when the obstacle or fin structure is added. The resultant maximum flow rates are 47.07 mm3/s and 53.39 mm3/s, respectively, for the conventional micro nozzle/diffuser and the added two-fin structure in micro nozzle/diffuser operated at a frequency of 400 Hz. Yet the mass flow rate for two-fin design surpasses that of conventional one when the frequency is below 425 Hz but the trend is reversed with a further increase of frequency. This is because the maximum efficiency ratio improvement for added two-fin is appreciably higher than the other design at a lower operating frequency. In the meantime, despite the efficiency ratio of the obstacle structure also reveals a similar trend as that of two-fin design, its significant pressure drop (flow resistance) had offset its superiority at low operating frequency, thereby leading to a lesser flow rate throughout the test range.
%K micro pump
%K diffusers
%K nozzles
%K enhancement
%K flow rate
%U http://www.mdpi.com/1420-3049/17/2/2178