Diffusion flux to a distorted gas bubble at large Reynolds numbers

1977 ◽  
Vol 11 (4) ◽  
pp. 548-553 ◽  
Author(s):  
Yu. P. Gupalo ◽  
Yu. S. Ryazantsev ◽  
Yu. A. Sergeev
Keyword(s):  
Diffusion Flux ◽  
Reynolds Numbers ◽  
Gas Bubble

Viscous flows past spherical gas bubbles

1975 ◽  
Vol 69 (1) ◽  
pp. 179-189 ◽  
Author(s):  
D. C. Brabston ◽  
H. B. Keller
Keyword(s):  
Finite Difference ◽  
Boundary Value Problem ◽  
Drag Coefficient ◽  
Viscous Flow ◽  
Asymptotic Theory ◽  
Viscous Flows ◽  
Reynolds Numbers ◽  
Gas Bubble ◽  
Point Boundary ◽  
Good Agreement

Computations of the steady viscous flow past a fixed spherical gas bubble are reported for Reynolds numbers in the range 0·1 [les ]R[les ] 200. Good agreement with Moore's (1963) asymptotic theory for the drag coefficient is obtained forR[les ] 40 and with the well-known small-Rtheory forR[les ] ½. The method of series truncation is used to reduce the problem to a nonlinear two-point boundary-value problem, which is then solved by an accurate and efficient finite-difference procedure.

Conservative Scheme Application for the Numerical Modeling of the Diffusion Problem for a Single Bubble in an Acoustic Field

2014 ◽  
Vol 10 ◽  
pp. 32-37
Author(s):  
E.V. Butyugina ◽  
E.Sh. Nasibullaeva ◽  
I.Sh. Akhatov ◽  
N.A. Gumerov
Keyword(s):  
Nonlinear Dynamics ◽  
Acoustic Field ◽  
Total Mass ◽  
Numerical Scheme ◽  
Diffusion Flux ◽  
Liquid System ◽  
Diffusion Problem ◽  
Gas Bubble ◽  
Conservative Scheme ◽  
Strongly Nonlinear

In the present study a numerical method for simulation of the diffusion problem for a single gas bubble oscillating in an acoustic field is developed. The method is based on the conservative numerical scheme for the diffusion equation where diffusion flux continuity is acting as conservation law. This method allows one to take into account the influence of changing mass of the gas inside the bubble on the strongly nonlinear dynamics of a bubble. The numerical results obtained using the proposed method utilizing conservative scheme and the standard scheme, which does not conserve the total mass of the gas-liquid system, reveals that in the latter case the numerical error may accumulate and lead to physically incorrect results.

scholarly journals Numerical solution of free-boundary problems in fluid mechanics. Part 2. Buoyancy-driven motion of a gas bubble through a quiescent liquid

1984 ◽  
Vol 148 ◽  
pp. 19-35 ◽  
Author(s):  
G. Ryskin ◽  
L. G. Leal
Keyword(s):  
Weber Number ◽  
Free Boundary Problems ◽  
Reynolds Numbers ◽  
Gas Bubble ◽  
Qualitative Explanation ◽  
Boundary Problems ◽  
Spherical Cap ◽  
Quiescent Liquid ◽  
Complete Solutions ◽  
Quiescent Fluid

In this paper numerical results are presented for the buoyancy-driven rise of a deformable bubble through an unbounded quiescent fluid. Complete solutions, including the bubble shape, are obtained for Reynolds numbers in the range 1 ≤ R ≤ 200 and for Weber numbers up to 20. For Reynolds numbers R ≤ 20 the shape of the bubble changes from nearly spherical to oblate-ellipsoidal to spherical-cap depending on Weber number; at higher Reynolds numbers ‘disk-like’ and ‘saucer-like’ shapes appear at W = O(10). The present results show clearly that flow separation may occur at a smooth free surface at intermediate Reynolds numbers; this fact suggests a qualitative explanation of the often-observed irregular (zigzag or helical) paths of rising bubbles.

Investigation on the effect of leading edge tubercles of sweptback wing at low reynolds number

2020 ◽  
Vol 21 (6) ◽  
pp. 621
Author(s):  
Veerapathiran Thangaraj Gopinathan ◽  
John Bruce Ralphin Rose ◽  
Mohanram Surya
Keyword(s):  
Leading Edge ◽  
Reynolds Numbers ◽  
Sweep Angle ◽  
Laminar Separation ◽  
Low Reynolds Numbers ◽  
Flow Energy ◽  
Airplane Wing ◽  
Low Reynolds ◽  
Naca 0015 ◽  
Wing Performance

Aerodynamic efficiency of an airplane wing can be improved either by increasing its lift generation tendency or by reducing the drag. Recently, Bio-inspired designs have been received greater attention for the geometric modifications of airplane wings. One of the bio-inspired designs contains sinusoidal Humpback Whale (HW) tubercles, i.e., protuberances exist at the wing leading edge (LE). The tubercles have excellent flow control characteristics at low Reynolds numbers. The present work describes about the effect of tubercles on swept back wing performance at various Angle of Attack (AoA). NACA 0015 and NACA 4415 airfoils are used for swept back wing design with sweep angle about 30°. The modified wings (HUMP 0015 A, HUMP 0015 B, HUMP 4415 A, HUMP 4415 B) are designed with two amplitude to wavelength ratios (η) of 0.1 & 0.24 for the performance analysis. It is a novel effort to analyze the tubercle vortices along the span that induce additional flow energy especially, behind the tubercles peak and trough region. Subsequently, Co-efficient of Lift (CL), Co-efficient of Drag (CD) and boundary layer pressure gradients also predicted for modified and baseline (smooth LE) models in the pre & post-stall regimes. It was observed that the tubercles increase the performance of swept back wings by the enhanced CL/CD ratio in the pre-stall AoA region. Interestingly, the flow separation region behind the centerline of tubercles and formation of Laminar Separation Bubbles (LSB) were asymmetric because of the sweep.

Low Reynolds number flow around and heat transfer from a heated circular cylinder

2010 ◽  
Vol 1 (1-2) ◽  
pp. 15-20 ◽  
Author(s):  
B. Bolló
Keyword(s):  
Reynolds Number ◽  
Circular Cylinder ◽  
Lift Coefficient ◽  
Reynolds Numbers ◽  
Low Reynolds Numbers ◽  
Reynolds Number Flow ◽  
Two Dimensional Flow ◽  
Number Flow ◽  
Low Reynolds ◽  
Increasing Temperature

Abstract The two-dimensional flow around a stationary heated circular cylinder at low Reynolds numbers of 50 < Re < 210 is investigated numerically using the FLUENT commercial software package. The dimensionless vortex shedding frequency (St) reduces with increasing temperature at a given Reynolds number. The effective temperature concept was used and St-Re data were successfully transformed to the St-Reeff curve. Comparisons include root-mean-square values of the lift coefficient and Nusselt number. The results agree well with available data in the literature.

MULTIPLE-SCALE AND NUMERICAL ANALYSES FOR THE NONLINEAR OSCILLATIONS OF A GAS BUBBLE SURROUNDED BY A MAXWELL'S FLUID

2019 ◽  
Vol 46 (3) ◽  
pp. 261-275
Author(s):  
César Yepes ◽  
Jorge Naude ◽  
Federico Mendez ◽  
Margarita Navarrete ◽  
Fátima Moumtadi
Keyword(s):  
Nonlinear Oscillations ◽  
Multiple Scale ◽  
Numerical Analyses ◽  
Gas Bubble

TRANSONIC CROSS FLOW (M∞ = 0.8) OVER A CIRCULAR CYLINDER AT HIGH REYNOLDS NUMBERS

2012 ◽  
Vol 43 (5) ◽  
pp. 589-613
Author(s):  
Vyacheslav Antonovich Bashkin ◽  
Ivan Vladimirovich Egorov ◽  
Ivan Valeryevich Ezhov ◽  
Sergey Vladimirovich Utyuzhnikov
Keyword(s):  
Circular Cylinder ◽  
Cross Flow ◽  
Reynolds Numbers ◽  
High Reynolds Numbers ◽  
High Reynolds
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