A Parametric CFD Study for the Effect of Spanwise Parabolic Chord Distribution on the Thrust of an Untwisted Helicopter Rotor Blade

摘要

The effect of parabolic chord distribution and the taper stacking point location along the span of a helicopter rotor blade is analyzed in terms of the rotor thrust, torque and Figure of Merit. The main focus is on the thrust generated. The Reynolds Averaged Navier-Stokes computations are done using the FINE/turbo flow solver developed by NUMECA International. The Spalart-Allmaras turbulence model is used to calculate the viscosity. The baseline blade is selected as the Caradonna-Tung rotor blade. Various blade shapes were generated by setting a maximum chord length at different spanwise locations. Other blade shapes were generated by moving the taper stacking point from leading edge to trailing edge. All the new blade shapes have the same planform area as the baseline blade. The analyses are conducted for different rotational speeds under different collective pitch angles. It is observed that the generated thrust may increase to about 10% as the maximum chord moves towards the blade tip.