Details

Autor(en) / Beteiligte

• Konstandin, L.
• Schmidt, W.
• Girichidis, P.
• Peters, T.
• Shetty, R.
• Klessen, R. S.

Titel

Mach number study of supersonic turbulence: the properties of the density field

Ist Teil von

• Monthly notices of the Royal Astronomical Society, 2016-08, Vol.460 (4), p.4483-4491

Ort / Verlag

London: Oxford University Press

Erscheinungsjahr

2016

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• We analyse the scaling properties of turbulent flows using a suite of three-dimensional numerical simulations. We model driven, compressible, isothermal, turbulence with Mach numbers ranging from the subsonic ( $\mathcal {M} \approx 0.5$ ) to the highly supersonic regime ( $\mathcal {M}\approx 16$ ). The forcing scheme consists of both solenoidal (transverse) and compressive (longitudinal) modes in equal parts. We confirm the relation $\sigma _{s}^2 = \ln {(1+b^2\mathcal {M}^2)}$ between the Mach number and the standard deviation of the logarithmic density with b = 0.33. We find increasing deviations with higher Mach number from the predicted lognormal shape in the high-density wing of the density probability density function. The density spectra follow $\mathcal {D}(k,\,\mathcal {M}) \propto k^{\zeta (\mathcal {M})}$ with scaling exponents depending on the Mach number. We find $\zeta (\mathcal {M}) = \alpha \mathcal {M}^{\beta }$ with coefficients α = −2.1 and β = −0.33. The dependence of the scaling exponent on the Mach number implies a fractal dimension $D=2+1.05 \mathcal {M}^{-0.33}$ .