Abstract

This study investigates the effects of boundary wettability on the turbulent natural convection heat transfer in a rectangular enclosure. Two water contact angles (θ) of the bottom copper plate of enclosure, 10° and 162°, were established using a sol–gel method. The contact angle of the copper plate without surface modification (the plain surface) was approximately 95°. This study presents the measured results of the Rayleigh number (Ra) and the Nusselt number (Nu) for these three surfaces at three aspect ratios (AR=W/H) of 0.5, 1, and 2 for Rayleigh numbers ranging from 7.49×104 to 1.36×107. A power-law correlation is proposed to fit experimental results on the plain surface. As for the modified surfaces within the range of Rayleigh number studied, the results show that Nusselt numbers on the superhydrophobic surface are approximately 16% lower than predicted values obtained from the correlation on the plain surface. However, there is little difference in the Nusselt number between the plain surface and the superhydrophilic surface.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.