We study the properties of various Eulerian contributions to fluid particle acceleration by using well-resolved direct numerical simulations of isotropic turbulence, with the Taylor-scale Reynolds number $R_{\lambda }$ in the range $140–1300$. The variance of convective acceleration, when normalized by Kolmogorov scales, increases as $R_{\lambda }$, consistent with simple theoretical arguments, but differing from classical Kolmogorov's phenomenology, as well as Lagrangian extension of Eulerian multifractal models. The scaling of the local acceleration is also linear in $R_{\lambda }$ to the leading order, but more complex in detail. The strong cancellation between the local and convective acceleration—faithful to the random sweeping hypothesis—results in the variance of the Lagrangian acceleration increasing only as $R_{\lambda }^{0.25}$, as recently shown by Buaria and Sreenivasan [Phys. Rev. Lett. 128, 234502 (2022)]. The acceleration variance is dominated by the irrotational pressure gradient contribution, whose variance essentially follows the $R_{\lambda }^{0.25}$ scaling; the solenoidal viscous contributions are comparatively small and follow $R_{\lambda }^{0.13}$, which is the only acceleration component consistent with multifractal prediction.

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• Geophysical fluid dynamics
• Intermittency
• Isotropic turbulence
• Transport phenomena
• Turbulence
• Turbulence modeling
• Turbulence simulations
• Direct numerical simulations
• Lagrangian particle tracking
• Navier-Stokes equation
• Statistical hydrodynamics