Study on Natural Convection From a Buried Pipe With Backfill

Abstract

Heat transfer and fluid flow induced by thermal buoyancy from a buried pipe with backfill has been examined in this study. Hele-Shaw cells with different gap widths were constructed to simulate a porous medium with distinct permeablities. The flow visualization experiment was set up to investigate how a step change in the permeability of a backfill would affect the flow patterns from a heated pipe. Both permeable and impermeable top surfaces with different buoyancy strengths were considered in this experiment. Using time-elapsed photographs, one observes that the flow fields for permeable and impermeable top boundaries displayed distinct characteristics. The presence of recirculating cell in the more permeable layer was confirmed. The flow fields predicted by numerical work are in good agreement with those observed in the experiment. Thus it is expected that the actual flow field would closely resemble those reported in the present study.

Flow Simulation of Radiant Floor Heating System Using Hele-Shaw Analogy

“…The flow visualization experiment was set up to investigate how a step change in the permeability of a backfill would affect the flow patterns from a heated pipe. The flow fields predicted by numerical work [20] are in good agreement with those observed in the experiment [19]. For the present study, the flow visualization experiment was set up to investigate how a change in pipe spacing and pipe temperature would affect the flow patterns in the surrounded porous medium from the heated pipes.…”

“…The present work focuses on the study of the transport phenomena from the piping system through the surrounded porous media to the floor. Previous studies employing Hele-Shaw analogy, that are most closely resembled the problem at hand, are those reported by Ngo and Lai [19]. The flow visualization experiment was set up to investigate how a step change in the permeability of a backfill would affect the flow patterns from a heated pipe.…”