Animation of the unsteady Calculations

Six animations of the unsteady flow in the two cases were created. The animations were created by saving individual color images made with Plot3D or FAST, and combined sequentially using the Silicon Graphics software MEDIACONVERT. Five of the animations showed the change in blade-to-blade flow quantities with time. At midspaa, a Mach number contour animation showed how the flow in the interstage region was affected by the passing of the rotor. Animation of entropy contours was very useful in showing convection of the vane wake downstream. The blade sliced through and cut the vane wake into patches of flow that were transported downstream. The wake was stretched through the blade passage because the flow near the suction surface of a given blade was converted faster then the flow near the pressure side of the adjacent rotor. The passing of the vane wake also had a noticeable effect on the blade suction surface boundary layer.

Blade-to-blade animations of entropy, radial velocity, and tangential velocity contours at 10% span for the case with cavity flow showed the introduction of cavity flow in the hub endwall region. These animations demonstrated the passing of the rotor and illustrated how the rotor potential field caused the cavity flow to be unsteady even though the conditions specified at the cavity were constant. The sixth animation was made for visual comparison with test data. From test data, Purdue researchers made an animation of the velocity vectors in a circumferential plane between the trailing edge of the vane and the leading edge of the rotor. From the simulation, we made a similar animation of velocity vectors from the inlet of the rotor grid to the leading edge of the rotor. Both animations compared well with each other and demonstrated how the passing of the rotor affects the cavity flow and the velocity field in the interstage region.

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