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# Principal Exercises

## D75: Model list and basic test cases

Draft: Proposal for substantional model list and several corresponding test cases
Zh. Xu Research Center Karlsruhe

General considerations

Operation environment
Gravity
* 2D natural circulation in a closed vertical chamber bounded by a warm and a cold plate on each side
* Motions of hot / light gas bubbles in quiscent fluids
Boussinesq model
Solution strategy
Max Courant number
Convergence control
Accuracy
Governing equations
Fluid dynamics
Turbulence equations
Energy equation
* Thermal equilibrium problem in a closed adiabatic cube of stagnant airs with different initial temperatures, the balance temperature can be checked.
* Thermal conduct problem in an infinite plane in a thickness with different temperatures at both sides, the heat fluxes at the surface and the temperature field can be checked.
* Adiabatic expansion in a closed rectangular channel, and adiabatic compression in a rectangular channel with one closed end and a moving pressure boundary on other end
* Isothermal expansion and compression can be designed in 3D channels

Grid

Sensitivity on cell aspect ratio, cell size
* Uniformed flow in a 2D channel with no-slip or rough wall boundary. To observe the velocity profiles at the length of 15 times of diameter, and to clarify the different aspect ratios, sizes of cells being used.
* 3D pipe flow, check the same things as last case.

Boundary conditions

Flow inlet / outlet
* Pressure inlet, velocity inlet, mass flow inlet, inlet vent, intake fan
* Pressure outlet, pressure far-field, outflow, outlet vent, exhaust fan
External boundaries
* Wall, symmetry, periodic, axis
Internal face boundaries
* Fan, radiator, porous jump, wall, interior

Solver

Explicit / Implicit (1st or 2nd order)
2D/3D
Isotropy in space
* Heat and mass diffusion from a point in a free space (sufficiently big geometry)
* Transmission of a pressure pulse
Diffusion
* 1D, 2D and 3D mass diffusion in a free space
* 1D, 2D and 3D thermal diffusion in a free space
* Boundary value problems of nitrogen diffusing into advective air flows in 1D, 2D and 3D
* Nitrogen point source released into a free advective air flow in 1D, 2D and 3D

Multiphase

Continuous phase
Discrete phase
Particle
Drag law
Particle shape
Potential force
* Particle diffusion from point / line / area / volume sources into 1D / 2D / 3D advective air flows
* Continuous / instantaneous particle source problems
Droplet
Collision
Breakup
Liquid surface / film
Condensation
Vaporization
Moving liquid film

Viscosity

Inviscid
Laminar
Turbulence model
k-e
* Isotropy uniformed turbulence decay in a horizontal rectangular channel
k-w
three equations and more equations models
Large eddy simulation
Direct numerical simulation

Multi-component

Species transport
Premixed combustion
Non-premixed combustion
Turbulent chemistry model
Laminar flame
Complete combustion
Chemical equilibrium
Deflagration
Detonation
Shock wave
* Backward step
* Decay of discontinuity (Riemann problem)
* Sedov solution
Acoustics

Solidification & Melting(?)