Efficient Cooling Approach with Integrated PCM Rooftops for Sustainable Load Reduction in Buildings with Natural Ventilation Systems
Amirhossein Khayyaminnejad, Amir Fartaj
Abstract
A new micromixer named '(Y-U)H' is proposed based on the split and recombine (SAR) principle. Five different (Y-U)H mixers are constructed with varying vertical cylindrical connector height H. The optimization is carried out by changingthe height H from 0 mm to 0.8 mm at varying Reynolds numbers ranging from 1 to 100 using numerical simulation software Ansys 15.The numerical setup is validated by comparing the numerical data with the experimental results of a well-known SAR 'H' mixer.Proposed (Y-U)H mixers have superior mixing performance than the H mixer irrespective of Reynolds numbers.Furthermore, the (Y-U)H mixers show excellent efficiency ( > 90%) at low Reynolds numbers ( 1).However, efficiency declines with the incline of Reynolds numbers due to the absence of secondary flow, and efficiency is about 64% for Reynolds numbers ranging from 10 to 100.Mixing efficiency also depends on the vertical cylindrical connector height (H); both efficiency and pressure drop increase with the increase of vertical cylindrical height.The (Y-U)0.8 mm (H = 0.8 mm) mixer shows the highest maximum efficiency (74%) compared to all examined mixers.