{
    "grids": {
        "default": {
            "operators": {
                "xi": "upwind9",
                "eta": "upwind9"
            }
        },
        "grid0": {
            "x": { "linspace": { "start": -5, "end": 0, "steps": 50 } },
            "y": { "linspace" : { "start":0, "end" :5, "steps" :50 } },
            "boundary_conditions": {
                "south": { "neighbour": "grid1" },
                "north": { "neighbour": "grid1" },
                "east": { "neighbour": "grid3" },
                "west": { "neighbour": "grid3" }
            }
        },
        "grid1": {
            "x": { "linspace": { "start": -5, "end": 0, "steps": 50 } },
            "y": { "linspace" : { "start":-5, "end": 0, "steps" :50 } },
            "boundary_conditions": {
                "south": {"neighbour": "grid0"},
                "north": {"neighbour": "grid0"},
                "east": {"neighbour": "grid2"},
                "west": {"neighbour": "grid2"}
            }
        },
        "grid2": {
            "x": {"linspace":{"start":0, "end":5, "steps":50}},
            "y": {"linspace":{"start":-5, "end":0, "steps":50}},
            "boundary_conditions": {
                "south": {"neighbour": "grid3"},
                "north": {"neighbour": "grid3"},
                "east": {"neighbour": "grid1"},
                "west": {"neighbour": "grid1"}
            }
        },
        "grid3": {
            "x": {"linspace":{"start":0, "end":5, "steps":50}},
            "y": {"linspace":{"start":0, "end":5, "steps":50}},
            "boundary_conditions": {
                "south": {"neighbour": "grid2"},
                "north": {"neighbour": "grid2"},
                "east": {"neighbour": "grid0"},
                "west": {"neighbour": "grid0"}
            }
        }
    },
    "integration_time": 2.0,
    "initial_conditions": {
        "vortex": {
            "vortices": [{
                "x0": -1.0,
                "y0": 0.0,
                "eps": 1.0,
                "rstar": 0.5
            }],
            "mach": 0.5
        }
    }
}