Unexpected results for downward convection at small-angles raised the question of whether vertical natural convection is the same for rough and smooth plates. This photo shows the plate suspended vertically by steel wire from the two boards above. The ambient temperature sensor is taped to the table leg. I measured the natural convection over three temperature ranges as was done in the other natural convection runs.
If there is less convection than expected, then it could be due to
heat from one side reducing the convection of a side above it, as
happens in the upward facing case.
But slightly more convection than expected was measured. As the
plate is no longer in the wind tunnel, modeling the emissivity of
the room as 0.9 (versus 0.8 for the wind tunnel) brings the
simulation into reasonable agreement with measurement. It thus
appears that, at least for laminar flows from rectangular plates,
natural convection from a rough surface has the same magnitude as
convection from a smooth surface.
The graph below is linked to a pdf of the
measurements and simulations of natural convection in level and
Governance by those who do the work.
- ▼ 2016 (9)
- ► 2015 (17)
- ► 2011 (13)
- ► 2010 (13)