2D Euler Equations

The 2D Euler equations model inviscid, compressible flows in two spatial dimensions. It is configured by setting the name in the equation table to euler_2d.

Here is an example for the equation table of this equation system:

  equation = {
    name      = 'euler_2d',
    isen_coef = 1.4,
    r         = 287,
    numflux   = 'hll',
    material = {
      characteristic = 0.0,
      relax_velocity = 0.0,
      relax_temperature = 0.0
    }
  }
  equation.cv = equation.r / (equation.isen_coef - 1.0)

The fluid is described by the ideal gas constant (equation.r), the isentropic expansion coefficient (equation.isen_coef) and the isochoric specific heat (equation.cv). See atl_eqn_euler_module for all options.

Note: you have to use the modg_2d scheme to compute this equation system (scheme.spatial.name = 'modg_2d').

The following example setups are available:

• Gaussian pulse in density: Simple setup with a circular pulse that gets convected into a sponge layer. Illustrates the definition of a sponge.

• Modal Estimate for timestep restriction: Illustration of the use of modal estimation for the adaptive timestep that uses a pressure pulse in the initial condition.

• Shock Stabilization: Demonstrates the use of a spectral and covolume filter to stabilize the simulation for a planar moving shock.

• Toro 1 in x

• Toro 1 in y

• Toro 2

• Toro 3

• Toro 4

• Vorticity

• Wedge: Illustrates the supersonic movement of a sharp geometry (wedge).

• Modereduction: Illustrates the supersonic movement of a sharp geometry (wedge). Elements inside the wedge are reduced in computation using the modereduction feature.