Unsteady flowfield of a propfan at takeoff conditions

The unsteady flowfield of a propfan operation at takeoff conditions with angular inflow is examined by solving the three-dimensional Euler equations. The operating conditions considered are: Mach no. = 0.31, advance ratio = 1.6, and inflow angle to the propfan = 8.3 deg. The predicted results clearly show the cyclic variations of the blade power and thrust coefficients due to angular inflow. The flow changes from blade passage to passage are illustrated in terms of static pressure contours. The predicted blade surface pressure waveforms were compared with flight measurements. The predictions at the inboard radial station, r/R = 0.68, show reasonable agreement with flight data. At the outboard radial station, r/R = 0.95, where the interactions of the tip vortex, the tip-region flow and the blade wake appear to result in a complex nonlinear measured response. The prediction shows poor agreement