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Accelerated flows past a rigid sphere or a spherical bubble. Part 1. Steady straining flow

Published online by Cambridge University Press:  26 April 2006

Jacques Magnaudet
Affiliation:
Institut de Mécanique des Fluides de Toulouse, URA CNRS 005, Avenue Camille Soula, 31400 Toulouse, France
Mayela Rivero
Affiliation:
Institut de Mécanique des Fluides de Toulouse, URA CNRS 005, Avenue Camille Soula, 31400 Toulouse, France Present address: Intevep SA, Los Teques (EPPR-32) Apdo. 76343, Caracas 1070-A, Venezuela.
Jean Fabre
Affiliation:
Institut de Mécanique des Fluides de Toulouse, URA CNRS 005, Avenue Camille Soula, 31400 Toulouse, France

Abstract

This work reports the first part of a series of numerical simulations carried out in order to improve knowledge of the forces acting on a sphere embedded in accelerated flows at finite Reynolds number, Re. Among these forces added mass and history effects are particularly important in order to determine accurately particle and bubble trajectories in real flows. To compute these hydrodynamic forces and more generally to study spatially or temporally accelerated flows around a sphere, the full Navier–Stokes equations expressed in velocity–pressure variables are solved by using a finite-volume approach. Computations are carried out over the range 0.1 ≤ Re ≤ 300 for flows around both a rigid sphere and an inviscid spherical bubble, and a systematic comparison of the flows around these two kinds of bodies is presented.

Steady uniform flow is first considered in order to test the accuracy of the simulations and to serve as a reference case for comparing with accelerated situations. Axisymmetric straining flow which constitutes the simplest spatially accelerated flow in which a sphere can be embedded is then studied. It is shown that owing to the viscous boundary condition on the body as well as to vorticity transport properties, the presence of the strain modifies deeply the distribution of vorticity around the sphere. This modification has spectacular consequences in the case of a rigid sphere because it influences strongly the conditions under which separation occurs as well as the characteristics of the separated region. Another very original feature of the axisymmetric straining flow lies in the vortex-stretching mechanism existing in this situation. In a converging flow this mechanism acts to reduce vorticity in the wake of the sphere. In contrast when the flow is divergent, vorticity produced at the surface of the sphere tends to grow indefinitely as it is transported downstream. It is shown that in the case where such a diverging flow extends to infinity a Kelvin–Helmholtz instability may occur in the wake.

Computations of the hydrodynamic force show that the effects of the strain increase rapidly with the Reynolds number. At high Reynolds numbers the total drag is dramatically modified and the evaluation of the pressure contribution shows that the sphere undergoes an added mass force whose coefficient remains the same as in inviscid flow or in creeping flow, i.e. CM = ½, whatever the Reynolds number. Changes found in vorticity distribution around the rigid sphere also affect the viscous drag, which is markedly increased (resp. decreased) in converging (resp. diverging) flows at high Reynolds numbers.

Type
Research Article
Copyright
© 1995 Cambridge University Press

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References

Achenbach, E. 1974 Vortex shedding from spheres. J. Fluid Mech. 62, 209.Google Scholar
Amsden, A. & Harlow, F. 1972 The SMAC Method: A numerical technique for calculating incompressible fluid flow. Los Alamos Res. Lab. Rep. LA-4370.Google Scholar
Auton, T. R., Hunt, J. C. R. & Prud'homme, M. 1988 The force exerted on a body in inviscid unsteady non-uniform rotational flow. J. Fluid Mech. 197, 241.Google Scholar
Basset, A. B. 1888 A treatise in Hydrodynamics, vol. 2. Cambridge: Deighton Bell.
Bataille, J., Lance, M. & Marié, J. L. 1990 Some aspect of the modeling of bubbly flows. In Phase-Interface Phenomena in Multiphase Flow (ed. G. F. Hewitt, F. Mayinger & J. R. Riznic). Hemisphere.
Batchelor, G. K. 1967 An introduction to Fluid Dynamics. Cambridge University Press.
Boussinesq, J. 1885 Sur la résistance qu'oppose un fluide indéfini au repos, sans pesanteur, au mouvement varié d'une sphére solide qu'il mouille sur toute sa surface, quand les vitesses restent bien continues et assez faibles pour que leurs carrés et produits soient négligeables. C. R. Acad. Sci. Paris 100, 935.Google Scholar
Brabston, D. C. & Keller, H. B. 1975 Viscous flows past spherical gas bubbles. J. Fluid Mech. 69, 179.Google Scholar
Braîlovskaya, I. Y. 1965 A difference scheme for numerical solution of the two-dimensional nonstationary Navier–Stokes equations for a compressible gas. Sov. Phys. Dokl. 10, 107.Google Scholar
Clift, R., Grace, J. R. & Weber, M. E. 1978 Bubbles, Drops and Particles. Academic Press.
Conner, J. M. & Elgobashi, S. E. 1987 Numerical solution of laminar flow past a sphere with surface mass transfer. Num. Heat Transfer 12, 57.Google Scholar
Darwin, C. 1953 Note on hydrodynamics. Camb. Phil. Trans. 49, 342.Google Scholar
Dennis, S. C. R. & Walker, J. D. A. 1971 Calculation of the steady flow past a sphere at low and moderate Reynolds numbers. J. Fluid Mech. 48, 771.Google Scholar
Drew, D. A. & Lahey, R. T. 1979 Application of general constitutive principles to the derivation of multidimensional two-phase flows equations. Intl J. Multiphase Flow 5, 243.Google Scholar
Drew, D. A. & Wallis, G. B. 1992 Fundamentals of two-phase flow modeling. Symp. Two-Phase Flow Modelling, London (unpublished).
Fornberg, B. 1988 Steady viscous flow past a sphere at high Reynolds number. J. Fluid Mech. 190, 471.Google Scholar
Galpin, P. F. & Raithby, G. D. 1986 Treatment of non-linearities in the numerical solution of the incompressible Navier–Stokes equations. Intl J. Num. Meth. Fluids 6, 409.Google Scholar
Gatignol, R. 1983 The Faxén formulae for a rigid particle in an unsteady non-uniform Stokes flow. J. Méc. Théor. Appl. 1, 143.Google Scholar
Hadamard, J. S. 1911 Mouvement permanent lent d'une sphére liquide et visqueuse dans un liquide visqueux. C.R. Acad. Sci. Paris 152, 1735.Google Scholar
Harlow, F. H. & Welch, J. E. 1965 Numerical calculation of time-dependent viscous incompressible flow of fluid with free surface. Phys. Fluids 8, 2182.Google Scholar
Kang, I. S. & Leal, L. G. 1987 Numerical solution of axisymmetric, unsteady free-boundary problems at finite Reynolds number. I. Finite-difference scheme and its application to the deformation of a bubble in a uniaxial straining flow. Phys. Fluids 30, 1929.Google Scholar
Kang, I. S. & Leal, L. G. 1988 The drag coefficient for a spherical bubble in a uniform streaming flow. Phys. Fluids 31, 233.Google Scholar
Kang, I. S. & Leal, L. G. 1989 Numerical solution of axisymmetric, unsteady free-boundary problems at finite Reynolds number. II. Deformation of a bubble in biaxial straining flow. Phys. Fluids A 1, 644.Google Scholar
Kim, I. & Pearlstein, A. J. 1990 Stability of the flow past a sphere. J. Fluid Mech. 211, 73.Google Scholar
Lamb, H. 1932 Hydrodynamics, 6th Edn. Cambridge University Press.
Le Clair, B. P., Hamielec, A. E. & Pruppacher, H. E. 1970 A numerical study of the drag of a sphere at low and intermediate Reynolds numbers. J. Atmos. Sci. 27, 308.Google Scholar
Leal, G. 1989 Vorticity transport and wake structure for bluff bodies at finite Reynolds number. Phys. Fluids A 1, 124.Google Scholar
Levich, V. G. 1949 Bubble motion at high Reynolds numbers Zh. Eksp. Teoret. Fiz. 19, 18 (in Russian).Google Scholar
Levich, V. G. 1962 Physicochemical Hydrodynamics. Prentice Hall.
Lhuillier, D. 1982 Forces d'inertie sur une bulle en expansion se déplaçant dans un fluide. C.R. Acad. Sci. Paris 295(II), 95.Google Scholar
Magnaudet, J., Rivero, M., Legendre, D. & Fabre, J. 1995 Accelerated flows past a rigid sphere or a spherical bubble. Part 2. Uniform unsteady flows. J. Fluid Mech. (to be submitted).Google Scholar
Maxey, M. R. & Riley, J. J. 1983 Equation of motion for a small rigid sphere in a non-uniform flows. Phys. Fluids 26, 883.Google Scholar
Moin, P. & Kim, J. 1985 Application of a fractional-step method to incompressible Navier–Stokes equations. J. Comput. Phys. 59, 308.Google Scholar
Moore, D. W. 1963 The boundary layer on a spherical gas bubble. J. Fluid Mech. 16, 161.Google Scholar
Naciri, A. 1992 Contribution à l’étude des forces exercées par un liquide sur une bulle de gaz: portance, masse ajoutée et interactions hydrodynamiques. Thése de Doctorat, Ec. Centrale de Lyon.
Natarajan, R. & Acrivos, A. 1993 The instability of the steady flow past spheres and disks. J. Fluid Mech. 254, 323.Google Scholar
Oliver, D. L. R. & Chung, I. N. 1987 Flow about a sphere at low to moderate Reynolds numbers. J. Fluid Mech. 177, 1.Google Scholar
Peyret, R. & Taylor, T. 1983 Computational Methods for Fluid Flow. Springer.
Pope, S. B. 1978 The calculation of turbulent recirculating flows in general orthogonal coordinates. J. Comput. Phys. 26, 197.Google Scholar
Proudman, I. & Pearson, J. R. A. 1957 Expansions at small Reynolds for the flow past a sphere and a circular cylinder. J. Fluid Mech. 2, 237.Google Scholar
Pruppacher, H. R., Le Clair, B. P. & Hamiliec, A. E. 1970 Some relations between drag and flow pattern of viscous flow past a sphere and a cylinder at low and intermediate Reynolds numbers. J. Fluid Mech. 44, 781.Google Scholar
Rallison, J. M. 1984 The deformation of small viscous drops and bubbles in shear flows. Ann. Rev. Fluid Mech. 16, 45.Google Scholar
Ribczynski, W. 1911 On the translatory motion of a fluid sphere in a viscous medium. Bull. Intl Acad. Pol. Sci. Lett.: Sci. Math. Nat. (A), 40 (in German).Google Scholar
Rimon, Y. & Cheng, I. 1969 Numerical solution of a uniform flow over a sphere at intermediate Reynolds numbers. Phys. Fluids 12, 949.Google Scholar
Rivero, M. 1991 Etude par simulation numérique des forces exercées sur une inclusion sphérique par un écoulement accéléré. Thése de Doctorat, Inst. Polytech. de Toulouse.
Ryskin, G. & Leal, L. G. 1984a Numerical solution of free boundary problems in fluid mechanics. Part 1. The finite difference technique. J. Fluid Mech. 148, 1.Google Scholar
Ryskin, G. & Leal, L. G. 1984b Numerical solution of free boundary problems in fluid mechanics. Part 3. Uniaxial straining flow. J. Fluid Mech. 148, 37.Google Scholar
Ryvkind, V. Y. & Ryskin, G. 1976 Flow structure in motion of a spherical drop in a fluid medium at intermediate Reynolds number. Fluid Dyn. 11, 5.Google Scholar
Sakamoto, H. & Haniu, H. 1990 A study of vortex shedding from spheres in a uniform flow. Trans. ASME I: J. Fluids Engng 112, 386.Google Scholar
Stokes, G. G. 1851 On the effect of the internal friction of fluids on the motion of pendulums. Trans. Camb. Phil. Soc. 9, 8.Google Scholar
Taneda, S. 1956 Studies on wake vortices (III). Experimental investigation of the wake behind a sphere at low Reynolds numbers. J. Phys. Soc. Japan 11, 1104.Google Scholar
Taylor, G. I. 1928 The forces on a body placed in a curved or converging stream of fluid. Proc. R. Soc. Lond. A 120, 260.Google Scholar
Taylor, T. D. & Acrivos, A. 1964 On the deformation and drag of a falling viscous drop at low Reynolds number. J. Fluid Mech. 18, 466.Google Scholar
Tchen, C. M. 1947 Mean value and correlation problems connected with the motion of small particles suspended in a turbulent fluid. PhD dissertation, Technische Hogeschool Delft.
Tollmien, W. 1938 Uber krafte und momente in schwach gekrummten oder konvergenten stromungen. Ing.-Arch. 9, 308.Google Scholar
Voinov, V. V., Voinov, O. V. & Petrov, A. G. 1973 Hydrodynamic interactions between bodies in a perfect incompressible fluid and their motion in non-uniform streams. Prikl. Math. Mekh. 37, 680.Google Scholar