论文标题
简单而活跃的二元流体湍流中的能量转移{\ bf { - }}一个不可压缩的MHD湍流的朋友
Energy transfer in simple and active binary fluid turbulence {\bf {-}} a false friend of incompressible MHD turbulence
论文作者
论文摘要
在统计同质性的假设下，研究了三维完全发达的二元流体湍流中惯性范围的能量转移。使用两个点统计，以两点增量和（ii）两点相关器来得出与能量级联相对应的精确关系（i）。尽管有明显的相似之处，但发现二元流体湍流的确切关系与不可压缩的MHD湍流不同（Politano and Pouquet，Grl，1998）。 除了通常的直接能量级联外，在某些情况下，还可以根据活性参数的强度以及流体速度的两点增量和组成梯度场之间的相互作用来推测能量反向级联。确切关系的另一种形式也是根据“ upsilon”变量得出的，随后的现象学也提出了预测$ k^{ - { - {3}/{2}} $法律的湍流能量。
Inertial range energy transfer in three dimensional fully developed binary fluid turbulence is studied under the assumption of statistical homogeneity. Using two point statistics, exact relations corresponding to the energy cascade are derived (i) in terms of two-point increments and (ii) two-point correlators. Despite having some apparent resemblances, the exact relation in binary fluid turbulence is found to be different from that of the incompressible MHD turbulence (Politano and Pouquet, GRL, 1998). Besides the usual direct cascade of energy, under certain situations, an inverse cascade of energy is also speculated depending upon the strength of the activity parameter and the interplay between the two-point increments of the fluid velocity and the composition gradient fields. An alternative form of the exact relation is also derived in terms of the `upsilon' variables and a subsequent phenomenology is also proposed predicting a $k^{-{3}/{2}}$ law for the turbulent energy spectrum.
