3-body-simulation

Small simulator for N body problems to learn C++ and some physics. The simulator outputs a csv file with the positions of the bodies at each timestep. These positions can be plotted with the python script provided.

Showcase

The following gif shows the solar system simulation with the provided config file. The code is sufficiently fast to simulate the solar system (10 bodies) for 1 billion seconds in around 5 min.

Now, let's see what happens when we add a rogue sun to the solar system. The second sun has the same mass as the original sun and quickly disrupts the orbits of the planets.

Installation

Install necessary packages

sudo apt-get install build-essential cmake

Install the python requirements

poetry install

Usage

A json config is required with the following format:

{
    "Logging": {
        "LogFile": "log.txt",
        "LogEvery": 1000
    },
    "Simulation": {
        "Timestep": 1,
        "Duration": 1000000,
        "DataFile": "data.csv",
        "WriteEvery": 1000
    },
    "Bodies": {
        "Body1": {
            "Name": "Mercury",
            "Mass": 3.301e23,
            "Pos": [
                57.909e9,
                0.0,
                0.0
            ],
            "Vel": [
                0.0,
                47.36e3,
                0.0
            ]
        },
        "Body2": {
            "Name": "Venus",
            "Mass": 4.867e24,
            "Pos": [
                108.209e9,
                0.0,
                0.0
            ],
            "Vel": [
                0.0,
                35.02e3,
                0.0
            ]
        }
    }
}

Then run the program with the config file as argument

./3-body-simulation -c config.json

Such a config for the solar system is provided in the app directory.