Picture 1. Wireframe of a section of the compressor. The outer diameter is 87 mm.

wireframe

Picture 2. Deformation due to 110000/min of rotational speed. The amplification factor is set to 20.

displacements

Picture 3. Von Mises stress due to 110000/min rotational speed. Plastification is considered. The peak stress in the bore is with 310 MPa slightly above yield stress. With that value crack-initiation will probably occur after 2000 start-stop cycles. The values along the blade-root are uncertain because the fillet-radius is not modeled.

stresses

Picture 4. Increase in diameter vs. rotational speed. Burst will occur at about 170000/min. This is equivalent to a tip-speed of 775 m/s.

burst

Picture 5. Equivalent plastification at the last converging time-step of the burst calculation at about 169000/min.

plastic strains

Picture 6. Frequency diagram of the compressor-blades. Resonances with the vanes can not be avoided.

frequency diagram

Picture 7. Modeshape of the lowest trailing edge mode (TE-5ND) and probably the most sensitive mode stimulated by the 19 vanes. For this calculation the new cyclic symmetry capabillity of CalculiX was used.

mode shape


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