The Effect of Gravity on Bubble-Particle Collisions in Turbulent Flows
Gravity plays a significant role in bubble-particle collisions in turbulent flows, affecting the collision rate, spatial distribution, and collision velocity. Turbulence can both enhance and reduce the collision rate compared to the pure relative settling case, depending on the Stokes and Froude numbers.
Attenuation of Wall-Bounded Turbulence by Heavy Finite-Size Particles
The presence of shedding vortices around particles that cannot follow the ambient fluid motions leads to additional energy dissipation, which reduces the turbulent energy production from the mean flow, resulting in the attenuation of wall-bounded turbulence.
Optimizing Synthetic Jet Flow Control through Duty Cycle and Blowing Ratio Variations
Varying the duty cycle and blowing ratio of synthetic jet actuators can effectively control flow separation over an airfoil, with low-duty cycle, high-blowing ratio strategies providing power-efficient flow reattachment.
Eliminating the Nonlinear Kelvin Wake Behind a Moving Body on the Water Surface
It is possible to eliminate the nonlinear Kelvin wake behind a moving body on the water surface by carefully choosing the forcing distribution, and the corresponding wave-free solution is stable.
Quantifying and Modeling Fluctuations in Colloidal Currents through Microfluidic Channels
The power spectral density of fluctuations in colloidal currents through microfluidic channels can be quantitatively modeled by considering the random arrival of particles and the distribution of particle velocities within the channel.
細菌乱流における2次元カスケードとコルモゴロフの対数正規スケーリング
2次元細菌乱流では、大規模な渦構造の存在により逆エネルギーカスケードが生じ、一方で小スケールでは粘性スケールより下でのエネルギー散逸が起こる。また、エンストロフィーカスケードは全スケールで生じ、非線形相互作用によって表現される。さらに、エネルギー散逸率とエンストロフィーの両方で対数正規統計が確認され、3次元乱流と同程度の間欠性パラメータを持つ。
Inverse Energy Cascade and Intermittent Scaling in Two-Dimensional Bacterial Turbulence
The collective movements of bacteria exhibit turbulence-like vortices, where the Richardson cascade plays an important role. The study examines the energy and enstrophy cascades and their associated lognormal statistics, confirming the coexistence of the inverse energy cascade and the intermittency correction of the velocity scaling in this active fluid system.
균일한 자유 표면 아래의 난류 구조와 에너지 전달
자유 표면 아래 균일 난류의 구조와 에너지 전달 특성을 실험적으로 규명하였다. 표면 근처에서 수직 속도 변동의 감소, 수평 속도 변동의 증가, 그리고 에너지 전달 메커니즘의 변화를 관찰하였다.
表面下の均質乱流における構造と エネルギー移動
自由表面下の均質乱流では、表面近傍での垂直速度変動の減少と水平速度変動の増大が観察される。これは表面の影響によるエネルギーの再分配に起因する。
Turbulence Structure and Energy Transfer Below a Free Surface in Homogeneous Flows
The free surface profoundly transforms the nature of the turbulence in its immediate proximity, altering the inter-scale energy transfer and the structure of upwellings and downwellings.