Abstract: The characters of dynam ic stall on NACA 0012 airfo il o scillat ing in p itch w ere inves2 t igated by experimentally determ ining p ressure dist ribut ion. The test parameters included a wide range of reduced frequencies, Reynolds numbers, amplitudes of scillation and mean angles of incidence. Two methods of highspeed data acquisitionscan and sample hold were used in the tests. The effects of filter cutoff frequencieswere investigated. The powerspect rawere analysied by VIEWDAC software package of highspeed data acquistion system. Finally, the comparisons with ther experiments and the retical calculation were presented.

Key words: airfoil, dynamic experiment, pressure measurement