Paper presented at the 6th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, South Africa, 30 June - 2 July, 2008.
An experimental analysis of the unsteady pressure
distribution on a two dimensional pitching Eppler-
361 airfoil was conducted by using transducers at
low speed wind tunnel. Dynamic pitching motion
was produced by oscillating the model over a range
of reduced frequencies, k=0.02355- 0.1413. In
addition, Static data were recorded as base line for
analysis and comparison. Both static and
oscillatory tests were conducted at Reynolds
numbers of 5 Re 5. The angle of
attack of the model was varying between 0 to 15
degrees. Surface static pressure was measured for
both upper and lower surfaces. Pitch rate, Reynolds
number and oscillation amplitudes and mean angle
of attack were varied to determine the effect on
pressure distributions. During the test a series of
the quasi-sinusoidal pitching motion were imposed
to the model. At different reduced frequency the
hysteresis loops were observed in variation of Cp
vs.α. Hysteresis loops when plotted against the
angle of attack were both clockwise and
counterclockwise. It was found that pitching
amplitudes, reduced frequency had strong effects in
pressure distribution, near the leading edge of the
airfoil.
