Influence of normalized frequency on timedependent aerodynamic characteristics of vane blading profiles
Abstract
Time dependent flow through mutually moving vane blading profiles is characterized by the frequency k = fz sub 1 b/2V, where f is the angular velocity of the rotor, z sub 1 is the number of blades of the fixed cascade, b is the working blade chord and V is the relative flow velocity. Different normalized frequencies can be obtained by changing the angular velocity fz sub 1 of the step nonuniformity wave along the casacade front in the gap between the guides and the rotor; fz sub 1 = 0 applies to the quasisteady state flow hypothesis. This paper proposes a method of specifying the normalized frequency, which ascertains its impact on the time dependent parameters of the vane blading while observing Mach number similitude and geometric similitude. A complete system of time dependent equations of gas dynamics and the explicit finite difference scheme of S. K. Godunov is applied to the case of two mutually moving cascades with the following characteristics in a normalized frequency range of k = 0 to 6; z sub 1 = 66, z sub 2 for the working cascade (rotor) = 110, relative nozzle cascade step is t sub 1/b sub 1 = 0.49, that of the rotor is t sub 2 b sub 2 = 0.57, the rotor speed is 157 rad/sec and the ratio of the static pressure per stage to the total pressure is p sub 2/p sub 0 = 0.16.
 Publication:

USSR Rept Eng Equipment JPRS UEQ
 Pub Date:
 January 1985
 Bibcode:
 1985RpEE.....Q..15G
 Keywords:

 Aerodynamic Characteristics;
 Guide Vanes;
 Profiles;
 Rotor Blades (Turbomachinery);
 Time Dependence;
 Amplitudes;
 Angular Velocity;
 Cascade Flow;
 Finite Difference Theory;
 Flow Distribution;
 Fluid Mechanics and Heat Transfer