摘要:

AbstractThis paper describes the work on extending the finite element method to cover interactions between a viscous flow and a moving body. The problem configuration of interest is that of an arbitrarily shaped body undergoing a simple harmonic motion in an otherwise undisturbed incompressible fluid. The finite element modelling is based on a primitive variables representation of the Navier‐Stokes equations using curved isoparametric elements. The non‐linear boundary conditions on the moving body are obtained using Taylor series expansion to approximate the velocities at the fixed finite element grid points. The method of averaging is used to analyse the resulting periodic motion of the fluid. The stability of the periodic solutions is studied by introducing small perturbations and applying Floquet theory. Numerical results are obtained for several example body shapes and compared with published experimental results. Good agreement is obtained for the basic non‐linear phenomenon of steady stre

ISSN:0271-2091    

DOI:10.1002/fld.1650070702

出版商:John Wiley&Sons, Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractThe magnetohydrodynamic flow of an incompressible, viscous, electrically conducting fluid in a rectangular duct, with an external magnetic field applied transverse to the flow, has been investigated. One of the duct's boundaries which is perpendicular to the magnetic field is taken partly insulated, partly conducting. An analytical solution has been developed for the velocity field and magnetic field by reducing the problem to the solution of a Fredholm integral equation of the second kind, which has been solved numerically. Solutions have been obtained for Hartmann numbersMup to 100. All the infinite series obtained are transformed to infinite integrals first and then to finite integrals which contain modified Bessel functions of the second kind. In this way, the difficulties associated with the computation of infinite integrals with oscillating integrands and slowly converging infinite series, the convergence of which is further affected for large values ofM, have been avoided. It is found that, asMincreases, boundary layers are formed near the non‐conducting boundaries and in the interface region, and a stagnant region is developed in front of the conducting boundary for velocity field. The maximm value of magnetic field takes place on the conducting part. These behaviours are shown on some graph

ISSN:0271-2091    

DOI:10.1002/fld.1650070703

出版商:John Wiley&Sons, Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractThe splitting difference scheme is used to study flow separation. Flows behind a circular cylinder are computed as a model problem. In view of the nature of the flow, the variables are transformed. The boundary condition for the pressure is given from an intermediate velocity. The free‐slip velocity boundary conditions on the rigid wall are given by interpolation. The multigrid algorithm is applied to the pressure iteration. We also choose better initial values for the model problem by means of the multigrid algorithm ide

ISSN:0271-2091    

DOI:10.1002/fld.1650070704

出版商:John Wiley&Sons, Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractIt is generally assumed in curved pipe flow analyses that the curvature ratio, δ, of the pipe is very small, in which case the flow depends on a single parameter, the Dean number. This is not the case if δ is not very small. To determine the importance of this effect we have numerically solved the full Navier‐Stokes equations, in primitive variable form, for arbitrary values of δ. A factored ADI finite‐difference scheme has been used, employing Chorin's artificial compressibility technique. The results show that the central‐difference calculation on a staggered grid is stable, without adding artificial damping terms, due to coupling between pressure and velocity. A spatially variable time step is used with a fixed Couran

ISSN:0271-2091    

DOI:10.1002/fld.1650070705

出版商:John Wiley&Sons, Ltd    

年代:1987

数据来源: WILEY

ISSN:0271-2091    

DOI:10.1002/fld.1650070706

出版商:John Wiley&Sons, Ltd    

年代:1987

数据来源: WILEY

ISSN:0271-2091    

DOI:10.1002/fld.1650070707

出版商:John Wiley&Sons, Ltd    

年代:1987

数据来源: WILEY

ISSN:0271-2091    

DOI:10.1002/fld.1650070701

出版商:John Wiley&Sons, Ltd    

年代:1987

数据来源: WILEY