Engineering Simulation in the Cornell MAE Fluids Program

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Engineering Simulation in the Cornell MAE Fluids
Program

• Brian J. Kirby
• Sibley School of Mechanical and Aerospace
  Engineering
• Cornell University

http//www.kirbyresearch.com
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This talk will primarily cover use of FLUENT in
MAE 423 and use of COMSOL in MAE 624

• FLUENT in MAE 423 Intermediate Fluid Dynamics
• COMSOL in MAE 624 Physics of Micro- and
  Nanoscale Fluid Mechanics

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MAE 423 Intermediate Fluid Dynamics is the
second fluids classtargeted for seniors and
M.Eng students
1-D/quasi 1-D inviscid comp. flow (shocks/nozzles
/diff)

• prerequisite MAE 323 Introductory Fluid
  Mechanics
• core class for thermal/fluids concentration
  energy concentration
• class size approx 30 seniors, 10 MEng
• texts Anderson Modern Compressible Flow White
  Viscous Fluid Flow

course coverage
NS solutions (Poiseuille, Couette, Stokes I,
Stokes II)
laminar BL theory (Blasius, Falkner-Skan)
turbulence modeling (k-eps)
turbulent BLs (law of the wall, inner/outer
variables)
Free shear flows (laminar wake)
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FLUENT projects are used in conjunction with
analytical treatment of topics
compressible flow over a wedge (viscous or
inviscid BC)

• FLUENT chosen owing to its ubiquity and good
  performance on problems of interest
• modules designed to communicate fluids concepts
  as well as rudimentary numerical concepts
• target audience CFD users, NOT CFD coders

FLUENT modules
converging-diverging nozzle
laminar pipe flow
laminar BL
turbulent pipe flow
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Compressible flow over a wedge is used to
illustrate oblique shock relations numerical
diffusion
1-D/quasi 1-D inviscid comp. flow (shocks/nozzles
/diff)

• flow over a wedge recover oblique shock
  relations
• adding viscous BC leads to shock steepening
• key concepts
• shock capturing
• numerical diffusion

compressible flow over a wedge (viscous or
inviscid BC)
image courtesy www.grc.nasa.gov
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Converging-diverging nozzle flows are used to
illustrate quasi-1D flows grid refinement
1-D/quasi 1-D inviscid comp. flow (shocks/nozzles
/diff)

• converging-diverging nozzle match quasi-1D
  nozzle relations
• 2D solution shows limitations of quasi-1D
  concepts but relative accuracy of resulting
  solutions
• key concepts
• grid refinement

converging-diverging nozzle
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Laminar pipe flow is used to illustrate canonical
NS solutions grid refinement
laminar pipe flow

• laminar pipe flow trivial solution comparison
  between numerics and analytical solution easy
• scheme orders apparent upon study with grid
  refinement
• key concepts
• grid refinement
• scheme order
• convection order vs. diffusion order

NS solutions (Poiseuille, Couette, Stokes I,
Stokes II)
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Blasius flat plate boundary layer is used to
illustrate similarity solutions

• flat plate similarity solution
• numerical solution allows visualization of
  dimensional solution for comparison to similarity
  solution
• key concepts
• farfield BCs

laminar BL
laminar BL theory (Blasius, Falkner-Skan)
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Turbulent pipe flow used to demonstrate role of
boundary layers, turbulence modeling

• turbulent pipe flow canonical problem for
  turbulence modeling
• wall functions coupled tightly to grid design
• key concepts
• k, eps transport equations
• turbulent viscosity
• law of the wall
• effect of boundary model on grid refinement

turbulence modeling (k-eps)
turbulent BLs (law of the wall, inner/outer
variables)
turbulent pipe flow
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COMSOL is used in MAE 624 owing to the low Re and
multiphysical nature of the problems

• FLUENT in MAE 423 Intermediate Fluid Dynamics
• COMSOL in MAE 624 Physics of Micro- and
  Nanoscale Fluid Mechanics

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MAE 624 Physics of Micro- and Nanoscale Fluid
Mechanics is directed to Ph.D. students
linear electrokinetics

• prerequisite MAE 323 Introductory Fluid
  Mechanics
• designed for micro/nanofluidics researchers
• class size approx 15
• texts Kirby coursepack

course coverage
electrical double layer and liquid state theory
Nernst-Planck equations
interfacial physics and chemistry fluid BCs
nonlinear electrokinetics diffuse-charge
dynamics dielectrophoresis
atomistic simulation
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COMSOL projects are used in conjunction with
analytical treatment of topics
laminar flow with slip BCs

• 2D laminar flows often serve to communicate
  concepts thus COMSOLs relative unsophistication
  with regards to NS solution is tolerable
• multiphysics approach allows incorporation of
  electricity and magnetism ion transport

COMSOL analysis
induced-charge electroosmosis
nanofluidic diodes
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Engineering Simulation in the Cornell MAE Fluids
Program

• Brian J. Kirby
• Sibley School of Mechanical and Aerospace
  Engineering
• Cornell University

http//www.kirbyresearch.com