Fluid Dynamics of Bacterial Turbulence
Fluid Dynamics of Bacterial Turbulence
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DOI：
10.1103/physrevlett.110.228102
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发表时间：
2013-05-28
影响因子：
8.6
通讯作者：
Goldstein, Raymond E.
中科院分区：
文献类型：
--
作者：
Dunkel, Joern;Heidenreich, Sebastian;Goldstein, Raymond E.
在各种生物流体中都观察到了自维持的湍流结构，但目前还没有定量的理论来解释它们的性质。我们报道了枯草杆菌高浓度三维悬浮液中的主动湍流实验，并将其与不可压缩细菌动力学的最小四阶矢量场理论进行了比较。通过成像细胞和跟踪胶体示踪剂对细菌和周围液体进行测速，得到了速度统计和动能超过2个数量级的关联的一致结果，揭示了随着游泳活动的增加和动能与凹陷之间的线性比例，流体记忆能力的下降。最佳拟合模型允许与实验数据定量吻合。
Self-sustained turbulent structures have been observed in a wide range of living fluids, yet no quantitative theory exists to explain their properties. We report experiments on active turbulence in highly concentrated 3D suspensions of Bacillus subtilis and compare them with a minimal fourth-order vector-field theory for incompressible bacterial dynamics. Velocimetry of bacteria and surrounding fluid, determined by imaging cells and tracking colloidal tracers, yields consistent results for velocity statistics and correlations over 2 orders of magnitude in kinetic energy, revealing a decrease of fluid memory with increasing swimming activity and linear scaling between kinetic energy and enstrophy. The best-fit model allows for quantitative agreement with experimental data.