标题： 随机流外围区域的被动标量输运 显示英文标题

标题： Passive scalar transport in peripheral regions of random flows

摘要： 我们研究了在随机（湍流）流动中靠近边界（壁面）的被动标量的统计特性，假设其扩散较弱。然后在被动标量混合的高级阶段，未混合残留物集中在靠近壁面的狭窄扩散层中，其向主体的传输通过外围区域（层流底层）。我们进行了不同空间维度$d$的拉格朗日数值模拟，并揭示了导致传输的结构，这些结构是被从扩散边界层拉到主体的被动标量舌状结构。我们研究了被动标量及其沿壁面积分的统计特性。这两个对象的矩在扩散边界层之外表现出标度行为。我们提出了一种解析方案来解释被动标量的标度，得到的指数在三维情况下与数值结果合理一致。 显示英文摘要

摘要： We investigate statistical properties of the passive scalar near boundaries (walls) in random (turbulent) flows assuming weakness of its diffusion. Then at advanced stages of the passive scalar mixing its unmixed residue is concentrated in a narrow diffusive layer near the wall and its transport to bulk goes through the peripheral region (laminar sublayer). We conducted Lagrangian numerical simulations of the process for different space dimensions $d$ and revealed structures responsible for the transport that are passive scalar tongues pulled from the diffusive boundary layer to bulk. We investigated statistical properties of the passive scalar and of the passive scalar integrated along the wall. Moments of both objects demonstrate scaling behavior outside the diffusive boundary layer. We propose an analytical scheme for explanation scaling of the passive scalar, the obtained exponents agree reasonably with numerics in 3d.