Long Phan
Dept. of Mechanical and Materials Engineering, Florida International University, Miami, FL 33174, USA
E. J. Lee
Building Integrated Renewable Energy Design, Korea Institute of Energy Research, Daejeon, South Korea
Soheil Soleimanikutanei
Dept. of Mechanical and Materials Engineering, Florida International University, Miami, FL 33174, USA
Cheng-Xian Lin
Department of Mechanical and Materials Engineering, Florida International University, 10555 W Flagler Street, Miami, Florida 33174, USA
Ground-air heat exchangers (GAHXs) play an important part in the geothermal technology applications. For
many applications, the difference between the ambient air and ground temperatures is an important limit factor
in the system's performance, as it is relatively unchanged throughout the day. To maximize this temperature
difference, optimization of the pipe wall area for enhanced convective heat transfer, while maintaining a short
pipe length was conducted. This includes the generation of turbulence within the fluids with special inserts, and
the selection of different materials of distinct thermal conductivities. In this paper, the plate-inserted pipe is
tested and verified against the regular smooth pipe for the enhancement in the air temperature drop through the
pipe during the summer days. A detailed computational fluid dynamics (CFD) model was established and
validated using the experimental data. Good agreement between computational and experimental data are
obtained. The numerical results also shown that when the plates are added, the temperature difference is much
improved with reasonable pressure drop.