Documented Examples

Results of the example problems provided in cholla/examples:

Documented 1D tests:

• 1D 123 test -- Demonstrates a scenario in which unmodified linearized Riemann solvers will return areas of negative density/pressure. From Toro's Riemann solvers and numerical methods for fluid dynamics (2009).
• 1D Creasey Shock -- A shock tube problem in which gas cools radiatively, forming dense region downstream. From Creasey et al. (2011)
• 1D Shu-Osher -- Demonstrates a scenario in which PPM will cut off maxima due to slope limiters. From Shu & Osher (1989).
• 1D Blast -- Two shocks initialized at either end of the domain converge and interact several times. From Woodward & Colella (1984).
• 1D Constant -- Initializes and maintains uniform density and pressure.
• 1D Noh -- Initializes an infinitely shock extending from the origin. Initially described in Noh (1987).
• 1D Sod -- A Riemann problem demonstrating the ability of a code to resolve shocks and contact discontinuities in a narrow region. From Sod (1978).
• 1D Sound Wave -- Initializes a compression/rarefaction wave.
• 1D Square Wave -- Initializes a square wave density pertubation.
• 1D Stationary -- Initializes a stationary contact. From Toro's Riemann solvers and numerical methods for fluid dynamics (2009).
• 1D Strong Shock -- A Riemann problem with more extreme contrasts between initial states (initial pressure and density discontinuities). From Fryxell et al. (2000).
• 1D Test 3 -- Riemann problem with an initial pressure discontinuity. From Toro's Riemann solvers and numerical methods for fluid dynamics (2009).
• 1D Trac-Pen -- Boosted shock wave test. From Trac & Pen (2004).
• 1D Two Shocks -- A Riemann problem consisting a two colliding shocks. From Toro's Riemann solvers and numerical methods for fluid dynamics (2009).

Documented 2D tests:

• 2D Gresho -- Produces a stationary, time-independent vortex in which the centrifugal force is exactly balanced by pressure gradients. Parameters from Liska & Wendroff (2003).
• 2D Implosion -- Non grid-aligned converging shock problem. Parameters from Liska & Wendroff (2003).
• 2D KH Discontinuous -- Demonstrates formation of eddies and mixing due to shear flows. Initialized with a discontinuous boundary.
• 2D KH Resolution Independent -- Demonstrates formation of eddies and mixing due to shear flows. Mixing is independent of resolution.
• 2D Noh -- Initializes an infinitely strong circular shock extending from the origin. Parameters from Liska & Wendroff (2003).
• 2D Rayleigh Taylor -- A gravitational instability consisting of a layer of lower-density fluid upwelling until a higher-density fluid. Parameters from Liska & Wendroff (2003).
• 2D Constant -- Initializes and maintains uniform density and pressure.
• 2D Disk -- 2D disk, initialized following a Kuzmin profile, in keplerian rotation.
• 2D Sod -- A 2D Riemann problem demonstrating the ability of a code to resolve shocks and contact discontinuities in a narrow region. From Sod (1978).
• 2D Sound Wave -- Initializes a compression/rarefaction wave.

Documented 3D tests:

• 3D Brio-Wu -- MHD Sod shock test. Parameters from Brio & Wu (1988).
• 3D Dai-Woodward -- Resolves all seven MHD waves. Parameters from Dai & Woodward (1998).
• 3D Einfeldt Strong Rarefaction -- MHD strong rarefaction problem. Parameters from Einfeldt et al. (1991).
• 3D KH Resolution Independent -- Demonstrates formation of eddies and mixing due to shear flows. Mixing is independent of resolution.
• 3D Noh -- Initializes an infinitely strong spherical shock extending from the origin. Parameters from Stone et al. (2008).
• 3D Ryu-Jones 1a -- MHD Riemann shock tube with five MHD waves. Parameters from Ryu & Jones (1995).
• 3D Ryu-Jones 4d -- MHD Riemann shock tube with switch on slow rarefaction. Parameters from Ryu & Jones (1995).
• 3D Spherical Collapse -- Gravitional collapse due to spherical overdensity.
• 3D Spherical Overpressure -- A spherical explosion due to an overpressurized region.
• 3D Uniform -- Initializes and maintains a uniform grid with zero density.
• 3D Zeldovich Pancake -- Initializes a plane contractaction (pancake) due to density pertubations. Originally described in Zeldovich (1970)
• 3D Advecting Field Loop -- MHD test. Demonstrates advection of a magnetic loop across the grid. Parameters from Gardiner & Stone (2008).
• 3D Alfven Wave -- MHD test, initializing Alfven waves.
• 3D Circularly Polarized Alfven Wave -- Exact nonlinear MHD solution. Parameters from Gardiner & Stone (2008).
• 3D Constant -- Initializes and maintains uniform density and pressure.
• 3D Disk -- Initializes a 3D hydrostatic disk.
• 3D Fast Magnetosonic -- MHD test. Initializes a fast magnetosonic (low frequency compressional) wave.
• 3D MHD Blast -- MHD test consisting of low strong shocks and rarefactions. Parameters from Gardiner & Stone (2009).
• 3D MHD Contact Wave -- MHD linear wave with discontinous density but constant pressure.
• 3D Orszag-Tang Vortex -- MHD test of turbulent dynamics and shock-shock interactions, forming a vortex. Parameters from Gardiner & Stone (2008).
• 3D Slow Magnetosonic -- MHD test. Initializes a slow magnetosonic (low frequency compressional) wave.
• 3D Sod -- A Riemann problem demonstrating the ability of a code to resolve shocks and contact discontinuities in a narrow region. Based on Sod (1978).
• 3D Sod 256 -- same as above but with higher resolution.
• 3D Sound Wave -- Initializes a compression/rarefaction wave.