摘要:

AbstractWe investigate the flow as it occurs above a single rotating disk when uniform suction is applied at the disk surface. It has been demonstrated by others that at zero suction repeated branching of the solution occurs as the parameter s is varied, where s is the ratio of the angular velocity of the fluid at infinity to the angular velocity of the disk. We show multiplicity of solution also at −0·82⩽α⩽1·15, where α is the suction parameter; for large absolute values of α the solution fails to turn back on itself and we obtain only the von Karman solution.We then generalize the von Karman solution for flow above a single rotating disk with uniform suction to include non‐axisymmetric solutions due to streaming at infinity. These solutions are continuous in an arbitrary parameter, the streaming velocity at infinity; for zero value of this parameter the asymmetric flow degenerates into the classical von Karman flow. Thus the classical solution is never isolated when considered within the framework of the Navier–Stokes equations: there are asymmetric solutions in every neighbourhood of the von K

ISSN:0271-2091    

DOI:10.1002/fld.1650060402

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractWe model the forming process as a fluid flow. A finite element program, FIDAP, which analyses flow problems, was used to calculate velocity and strain rates at points throughout the material during the deformation process. This allows predictions to be made on the shape and quality of the resulting part. The stress‐strain relation we used models the plastic flow of metals (Bingham fluids). The FEM approximation of such a fluid is tested by comparing results for a simple analytical example. In forming processes provision must be made for friction between dye and workpiece, and the program was modified accordingly. Two classical ring forming simulations are compared to published result

ISSN:0271-2091    

DOI:10.1002/fld.1650060403

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractWe are concerned with the numerical computation of progressive free surface gravity waves on a horizontal bed. They are regarded as families of bifurcation branches (λ,A)Qof constant dischargeQ.Numerically we determine two transition valuesQ1andQ2with corresponding transition bifurcation branches that classify waves into three disjoint branch setsB1,B2andB3. Their members are families of waves (λ,A)Qsatisfying the conditions 0

ISSN:0271-2091    

DOI:10.1002/fld.1650060404

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractSwirling flows are often employed in gas turbine combustion systems and high intensity industrial furnaces. A detailed analysis of the turbulence in the flow is necessary to achieve optimum combustion conditions. In this paper a method has been described to measure the turbulence levels in three directions using a hot wire anemometer. So far there is no established method available for measurement of turbulence in swirling and recirculating flows.The present method, it is hoped, will bridge the gap. The merit of the present method is the use of a single‐wire probe rather than the X‐probe. The method has been used for the measurement of turbulence levels in swirling recirculating flows generated by vane swirlers. From the measured turbulence levels, the kinetic energy of turbulence has been calculated and the results are compared with a well‐established numerical prediction method.Mean velocity measurements have also been made using a 3‐hole Pitot probe. The agreement between the measured and predicted values is quite satis

ISSN:0271-2091    

DOI:10.1002/fld.1650060405

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractA mathematical model of turbulent density‐driven flows is presented and is solved numerically. A form of thek–ϵ turbulence model is used to characterize the turbulent transport, and both this non‐linear model and a sediment transport equation are coupled with the mean‐flow fluid motion equations. A partitioned, Newton–Raphson‐based solution scheme is used to effect a solution. The model is applied to the study of flow through a circular secondary sedimen

ISSN:0271-2091    

DOI:10.1002/fld.1650060406

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

ISSN:0271-2091    

DOI:10.1002/fld.1650060407

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

ISSN:0271-2091    

DOI:10.1002/fld.1650060408

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

ISSN:0271-2091    

DOI:10.1002/fld.1650060401

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY