二维衰减湍流的速度加速度结构函数$^{\bf 1)}$
周泽友()
VELOCITY-ACCELERATION STRUCTURE FUNCTION IN TWO-DIMENSIONAL DECAYING TURBULENCE$^{\bf 1)}$
Zhou Zeyou()

图3. (a) 在尺度 $r/M=0.35$ 下,红色圆圈为 VASF,对其取负号使之为正. 绿色方块为构成 VASF 的第二项,非均 匀项,并也对其取负号. 蓝色星形为构成 VASF 的第三项,尺度间传递项的实验值. 这三者在不同空间位置 $tU/M$ 的值. (b) 纵坐标为 $-\langle \delta u_i \delta a_i \rangle$ 的对数值,横坐标为 $-\langle (U_n/2){\rm \partial} D_{ii} /{\rm \partial} X_n\rangle$ 的对数值,数据基本都落在图中等值线附近

Fig.3. (a) In scale $r/M=0.35$, the red circles are VASF which have been multiplied by $-1$. Green squares are inhomogeneous term which is the second term of VASF. Blue stars are the scale-to-scale transfer term which is the third term of VASF. We plot their values in different downstream location $tU/M$. (b) The ordinate is the logarithmic value of $-\langle \delta u_i \delta a_i \rangle$, the abscissa is the logarithmic value of $-\langle (U_n/2){\rm \partial} D_{ii} /{\rm \partial} X_n\rangle$, most of the data lies around the contour line