Abstract explosion modelling - how to?

[Krash]

I want to model an extremely simplified explosion in a little program I have. All I want to do is accurately model the movement of a single object affected by this explosion in a void.

Here's how I'm thinking about things so far. I'd appreciate it if people could tell me whether I'm on the right track or not.

- Model the "explosion" as an infinite number of forces of equal magnitude, originating from a point in space.
- The movement of the object is along the 3d line between the object's center of mass and the origin of the explosion, and is inversely proportional to it's distance from that origin.

The rotation of the object has me a little stumped, but I think this would be accurate:
- Take the surface of the object nearest the explosion, and find the infinite 3d plane of which it is a part.
- Find the perpendicular distance between that plane and the origin. This becomes the magnitude of the tortional force.
- Find the point on the plane which this perpendicular strikes, and find it's distance from the object's center of mass. This, combined with the above magnitude, allows the calculation of the speed at which the object will now spin.
- The axis of rotation is the line perpendicular to both the extended plane and it's initial perpendicular, passing through the object's center of mass.

Is all that accurate, assuming the object is a regular polyhedron? The calculations would obviously be more complex if I wanted to include such things as gravity, air, temperature, etc, but I don't. I just want a few polygons to fly away from a point in a realistic fashion.

Assuming that it is accurate, can someone point me in the direction of the equations for finding the values I'd need? I'd prefer them in cartesian coordinates, but polar would do...

- Krash

 

[Greg Bernhardt]

Explosion modeling is a technique used in computational fluid dynamics (CFD) to simulate the propagation of an explosion in a fluid. The explosion is usually modeled as a shock front traveling at a constant speed. The shock wave is modeled as a discontinuity in the pressure and density fields.

A shock front can be defined as a point on a pressure-density curve where the pressure and density change discontinuously. The propagation of the shock front is a one-dimensional adiabatic process.

The shock front expansion is a result of a pressure drop across the shock front. The pressure drop across a shock front is a function of the density of the fluid. As the fluid tries to reach equilibrium, the density decreases, which causes the shock front to propagate.