November 14, 2019
blastFoam is Synthetik's free and open source CFD airblast code available on GitHub: https://github.com/synthetik-technologies/blastfoam blastFoam is a solver for multi-component compressible flow with application to high-explosive detonation, explosive safety and airblast. blastFoam is developed by Synthetik Applied Technologies: https://www.synthetik-technologies.com
The evolution of a two phase, compressible, and inviscid mixture can be defined by a set of coupled evolution equations for mass, momentum, and energy.
where is the mixture density, the mixture velocity, the total energy, the pressure, and and are the density and volume fraction of each phase.
The pressure will be defined using a specified equation of state where the mixture internal energy, densities, and volume fraction are used to calculate the total pressure. The equations of state will be used in the Mie-Gruneisen form.
The mixture pressure is defined using the Mie-Gruneisen from using
where
and is dependent on the equation of state.
The speed of sound within a give phase is give by
with
and is again dependent on the equation of state.
For a gas described by the generalized van der Waals equation of state, the pressure is defined as
where , , , and are material parameters. Writing the above equation in M.G. form, we obtain
and
For a material obeying the Tait EOS, the pressure is defined as
where , , and are material properties. In M.G. form, we have
and
For a material obeying the stiffened EOS, the pressure is defined as
where and are material properties, and
The more complicated JWL EOS is often used to define energetic materials, and has a reference pressure given by
, , , , , and are the material properties. The functions of the EOS are given by
and
is anther material parameter which denotes a reference energy state.
The Cochran Chan EOS can be used to describe solid material, and has a reference pressure given by
, , , , , and are the material properties. The functions of the EOS are given by
where again, is a material parameter which denotes a reference energy state.