AeroCFD and HyperCFD

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AeroCFD and HyperCFD

• Aerodynamics Software for Rockets
• by
• David Cummings

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Aerodynamic Software Tools

• Developed by AeroRocket
• www.aerorocket.com
• AeroCFD - 90
• HyperCFD - 150

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What is CFD?

• CFD Computational Fluid Dynamics
• Applies numerical methods to solve the inviscid,
  incompressible potential flow equations using
  panel methods
• Compressibility and viscous effects are added in
  to get the total body aerodynamics
• CFD methods used in the aerospace industry

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AeroCFD Features

• Analyzes conventional axi-symmetrical rocket
  configurations
• Analyze flows up to Mach 0.8
• Computes CD, CL, Cm, and Cp
• Imports fins from Rocksim
• Plots the velocity and pressure contours for
  graphical visualization of the flow field
• Plots pressure distribution over entire rocket

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HyperCFD Features

• Analyzes conventional axi-symmetrical rocket
  configurations
• Analyze flows from Mach 1.05 to 20
• Computes CD, CN, Cm, and Cp

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• Demonstration
• of
• AeroCFD
• and
• HyperCFD

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99k Nose Cone Drag Study
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99k Nose Cone Drag Study
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99k Nose Cone CP Study
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99k Transition Drag Study
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Static Margin of Mile High Bird

• Method Ignition End of Burnout
• Launch Rod
• Rocksim 1.90 1.94 2.94
• Barrowman 1.33 1.37 2.37
• AeroCFD -0.03 0.01 1.01
• Static margin given in calibers.

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Center of Pressure of 99k

• Method From Diff in
• Nose Tip Calibers
• Barrowman 189.43 0.00
• Rocksim 187.72 0.22
• AeroCFD 183.99 0.71
• 1 caliber 7.7 inches

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Minuteman II by Aaron Miles
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Minuteman II Static Stability

• Method CP from Static Margin
• Nose Tip in Calibers
• Rocksim 50.3 1.59
• Barrowman 50.3 1.59
• AeroCFD 33.2 -0.64
• One caliber is 7.67.
• Total rocket length is 74.0.

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Pressure Distribution Plot

• Cp (local pressure free stream
  pressure)/dynamic pressure
• Where would you put your vent holes for your
  avionics?

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An Observation

• The Barrowman method (also the Rocksim method)
  neglects the body tube airframes in its
  calculations.
• The CFD methods includes any effects on the body
  tube airframes.