Coagulation of inertial particles in supersonic turbulence

Coagulation driven by supersonic turbulence is primarily an astrophysical problem because coagulation processes on Earth are normally associated with incompressible fluid flows at low Mach numbers, while dust aggregation in the interstellar medium (ISM) for instance example of opposite regime. We study inertial particles compressible using high-resolution direct and shock-capturing numerical simulations a wide range numbers from nearly to moderately supersonic. The particle dynamics simulated representative effects size distribution rate due increasing number explored. show that time evolution mainly depends compressibility (Mach number). find average kernel $\langle C_{ij}\rangle$ scales linearly $\mathcal{M}_{\rm rms}$ multiplied combined colliding particles, is, C_{ij}\rangle \sim \langle (a_i + a_j)^3\rangle\, \mathcal{M}_{\rm rms}\tau_\eta^{-1}$, which qualitatively consistent expectations analytical estimates. A quantitative correction \langle(a_i a_j)^3\rangle(v_{\rm p,rms}/c_{\rm s})\tau_\eta^{-1}$ proposed can serve as benchmark future studies. argue R_c\rangle$ also enhanced compressibility-induced compaction particles.