Compressor Cascade Pressure Rise Prediction

1
Compressor Cascade Pressure Rise Prediction

• ME 491 Project
• Department of Mechanical Engineering, IUPUI
• Julia Zafian-Short
• December 2004

2
Outline

• Goals and Approach
• Computational Setup
• Results
• Summary and Conclusions

3
Goals and Approach

• To model flow around a NASA/GE E3 rotor blade.
• Apply 2-D CFD using Star-design.
• Quantitative post processing using starviz.

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Computational Setup

• Domain and boundary conditions
• Mesh
• Parameters
• Cell type and sizes (near wall and far field)
• Solution parameters
• Method
• Convergence criteria

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Domain, Boundary Conditions and Mesh
Inlet, velocity
60 m/s
Periodic
30 m/s
Periodic
Pressure
Symmetry No change Normal to Surface
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Mesh
Tetrahedral Cells
7 layers Surface size 0.1 Subsurface Thickness 0.5
Prismatic Cells
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Method

• Incompressible flow assumptions
• Upwind differencing
• High Reynolds number K-epsilon
• Convergence on 0.001Mass Flow Residual

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Results

• Velocity
• Pressure
• Pressure rise characteristic
• Flow features

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Tangential Velocity, Vy -70 to 20 m/s,
increment of 5 m/s
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Axial Velocity, Vz15 to 45 m/s, increment of 3
m/s
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Pressure97,900 to 100,400 Pa, increment 250Pa
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Stagnation Pressure100,400-101,600 Pa, increment
120 Pa
Wake
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Stagnation Pressure Coefficient-0.4 to 0,
increment of 0.04
Cp(P-Pref)/(0.5rVref2)
Dimensionless Stagnation Pressure (using
reference values from the inlet)
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Similar Calculations for a Range of Inlet Axial
Velocities.
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Streamline Comparison for Different Inlet
Velocities

• Inlet Velocity

Inlet Velocity
60 m/s
60 m/s
16 m/s
30 m/s
Separation Bubble
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Summary and Conclusions

• The operating limit for the incoming axial
  velocity is found to be 20 m/s for maximum
  pressure gradient.
• As the mass flow drops further, the angle between
  the flow and the leading edge of the blade
  increases, increasing the wake.