Microbubble Drag Reduction Mechanism Observed in Taylor-Couette Flow
نویسندگان
چکیده
منابع مشابه
Drag Reduction Using Polysaccharides in a Taylor–Couette Flow
Three different polysaccharides, aloe vera, Tamarind powder and pineapple fibers, are utilized as drag reducing agents in a turbulent flow. Using a Taylor–Couette setup, consisting of a rotating inner cylinder, for measuring the drag reduction, a range of Reynolds numbers from 4 × 104 to 3 × 105 has been explored in this study. The results are in good agreement with previous studies on polysacc...
متن کاملDrag reduction in bubbly Taylor-Couette turbulence.
In Taylor-Couette flow the total energy dissipation rate and therefore the drag can be determined by measuring the torque on the system. We do so for Reynolds numbers between Re=7 x 10(4) and Re=10(6) after having injected (i) small bubbles (R=1 mm) up to a volume concentration of alpha=5% and (ii) buoyant particles (rhop/rhol=0.14) of comparable volume concentration. In case (i) we observe a c...
متن کاملMicrobubbly drag reduction in Taylor-Couette flow in the wavy vortex regime
We investigate the effect of microbubbles on Taylor-Couette flow by means of direct numerical simulations. We employ an Eulerian-Lagrangian approach with a gas-fluid coupling based on the point-force approximation. Added mass, drag, lift, and gravity are taken into account in the modeling of the motion of the individual bubble. We find that very dilute suspensions of small non-deformable bubble...
متن کاملOscillating Taylor-Couette Flow
A flow transition in a coaxial rotating cylinder with only inner cylinder rotation was investigated using ultrasonic Doppler method for a wide range of Reynolds number up to 40 times critical Reynolds number (Rc). By analysing spatio-temporal velocity profiles, excitation functions of various transition modes such as wavy and modulated wavy modes were obtained using space-time Fourier expansion...
متن کاملUltimate turbulent Taylor-Couette flow.
The flow structure of strongly turbulent Taylor-Couette flow with Reynolds numbers up to Re(i)=2×10(6) of the inner cylinder is experimentally examined with high-speed particle image velocimetry (PIV). The wind Reynolds numbers Re(w) of the turbulent Taylor-vortex flow is found to scale as Re(w)∝Ta(1/2), exactly as predicted by Grossmann and Lohse [Phys. Fluids 23, 045108 (2011).] for the ultim...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Journal of the Visualization Society of Japan
سال: 2007
ISSN: 1884-037X,0916-4731
DOI: 10.3154/jvs.27.supplement1_129