## Abstract

The noninstantaneous behavior of the velocity correlation function for a turbulent fluid leads to memory effects in the equation of motion of a particle suspended in such a fluid. This effect is a direct consequence of the fluctuation-dissipation theorem, which connects the correlation properties of the random force with a memory function. As a result, the equation of motion of a suspended particle in a turbulent flow is an integro-differential rather than a differential equation, and the diffusion coefficient of a suspended particle and that of a fluid do not coincide even in the simplest model. The velocity correlation function of a particle and its diffusion coefficient are found for a simple model.

Original language | English |
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Pages (from-to) | 2154-2160 |

Number of pages | 7 |

Journal | Physics of Fluids |

Volume | 23 |

Issue number | 11 |

DOIs | |

State | Published - 1980 |