Ex-situ experimental study on extraction of droplet dynamic parameters based on droplet shape in PEMFC

ABSTRACT

An ex-situ visualization experimental system for the proton exchange membrane fuel cell (PEMFC) is developed to study the dynamic characteristics of a droplet in a square flow channel. The extraction of droplet dynamic contact angles based on droplet shape is performed by a customized image processing method. The best double circle fitting is found by comparing different fitting methods for contact angle extraction. The accuracy of double circle fitting is improved by the relationship between droplet shape and data analysis, and it achieves good consistency with manual measurement. The contact angle hysteresis gradually increases to the maximum during droplet evolution until the droplet detaches. With the increase of gas flow rate, the contact angle hysteresis decreases at the instant of detachment, the droplet size and removal time are found to decrease, and the oscillation of the droplet is severer before droplet detachment.

KEYWORDS:

• Contact angle extraction
• dynamic characteristics
• flow visualization
• proton exchange membrane fuel cell
• water management

Acknowledgments

This work is financially supported by the National Natural Science Foundation of China (Grant No. 51706153 and 51506122), and the Natural Science Foundation of Heilongjiang Province of China (Grant No. QC2018055).

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [Grant No. 51706153 and 51506122], and the Natural Science Foundation of Heilongjiang Province of China [Grant No. QC2018055].