Abstract:
This research investigated the flow patterns and heat transfer characteristics of
water and air in a tube heat exchanger equipped with annular copper foam. The study
focused on the impact of superficial liquid velocities, superficial air velocities, pore
density of the copper foam, and the foam's filling rate on the two-phase flow patterns,
heat transfer coefficients, and pressure drops. The double-tube heat exchanger,
containing annular copper foam, featured an outer tube made from transparent acrylic
to facilitate observation of the two-phase flow behavior. The copper foam was inserted
at ratios of 45.7%, 65.7%, and 100%, with pore densities of 30PPI, 40PPI, and 50PPI. The
flow directions of the hot and cold fluids were in counterflow in the horizontal plane.
The experiment identified six distinct flow patterns: bubbly flow, plug flow, slug flow,
annular/slug flow, central core mist flow, and mist flow. Incorporating copper foam into