Heat transfer distributions around nominal ice accretion shapes formed on a cylinder in the NASA Lewis Icing Research Tunnel
Abstract
Local heat transfer coefficients were obtained on irregular cylindrical shapes which typify the accretion of ice on circular cylinders in cross flow. The shapes were 2, 5, and 15 min accumulations of glaze ice and 15 min accumulation of rime ice. These icing shapes were averaged axially to obtain a nominal shape of constant cross section for the heat transfer tests. Heat transfer coefficients were also measured around the cylinder with no ice accretion. The models were run in a 15.2 x 68.6 cm (6 x 27 in.) wind tunnel at several velocities. The models were also run with a turbulence producing grid which gave about 3.5 percent turbulence. The effect of roughness was also simulated with sand grains glued to the surface. Results are presented as Nusselt number versus angle from the stagnation line for the smooth and rough models for both high and low levels of free stream turbulence. Roughness of the surface in the region prior to flow separation plays a major role in determining the heat transfer distribution. Free stream turbulence does not affect the distribution of heat transfer in this region but raises the level by a nearly uniform amount. For the rime shape, roughness had a larger effect in the near wedge shaped region past the initial separation point.
- Publication:
-
AIAA, Aerospace Sciences Meeting
- Pub Date:
- January 1984
- Bibcode:
- 1984aiaa.meetR....V
- Keywords:
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- Cylinders;
- Heat Transfer Coefficients;
- Ice Formation;
- Wind Tunnel Tests;
- Circular Cylinders;
- Deposition;
- Nusselt Number;
- Shapes;
- Turbulent Flow;
- Fluid Mechanics and Heat Transfer