摘要:

AbstractVortex formations represent a particular case of discontinuous flow of fluids. For the most, they are non‐stationary formations with a pronounced whirling motion of intensity that is characterized by velocity circulation about the center, decreasing or increasing with time. They always contain a core with a marked component of rotational motion and one or two discontinuity surfaces or vortex layers rolling up in the form of spirals. In addition to the intensive whirling motion, they also exhibit centripetal or centrifugal motions.For cases where in the first approximation the effect of viscosity may be neglected and the medium considered an incompressible fluid, the paper demonstrates that all basic features of vortex formations may be described by a solution of Laplace's equation constructed as a convenient combination of algebraic and logarithmic singularities. The solution thus obtained is dependent on time insofar that all conditions of compatibility of the flow must be satisfied at all times in every point (particularly on the discontinuity surface). Several plane models of vortex formations are considered and with their aid a model is constructed of a flow field with vortex pair behind a cylinder starting from rest. A comparison of theoretical and experimental results is presented for this cas

ISSN:0044-2267    

DOI:10.1002/zamm.19660460202

出版商:WILEY‐VCH Verlag    

年代:1966

数据来源: WILEY

摘要:

AbstractEs wird ein Summenansatz aus Keplerbewegungen des Raumfahrzeugs um alle beteiligten Himmelskörper aufgestellt, welcher jede Anfangswertaufgabe der Störungsrechnung zugänglich macht und für begrenzte Zeiträume von hoher Genauigkeit ist. Ausdehnung auf zusätzliche Kräfte führt in einigen Standardfällen auf geschlossene Näherungen für das n‐Körperproblem der Raumfahrt einschl

ISSN:0044-2267    

DOI:10.1002/zamm.19660460203

出版商:WILEY‐VCH Verlag    

年代:1966

数据来源: WILEY

摘要:

AbstractEs wird gezeigt, daß in den Anwendungen häufig auftretende Pseudometrische Räume (s. 2) von Rieszschen Halbordnungs‐Banachräumen erzeugt werden. Dadurch ist es möglich, einen allgemeinen Satz über die Existenz und Fehlerabschätzung von Lösungen einer nichtlinearen Operatorgleichung als einfachen Spezialfall des Schauderschen Fixpunktsatzes zu gewinnen, ohne die pseudometrische Struktur zu

ISSN:0044-2267    

DOI:10.1002/zamm.19660460204

出版商:WILEY‐VCH Verlag    

年代:1966

数据来源: WILEY

摘要:

AbstractA numerical method for obtaining solutions of laminar boundary layer equations for incompressible fluids due to Hartree has been modified here to obtain solutions of the problem of laminar flow of a conducting fluid with constant properties in the entrance region of a semi‐infinite flat duct with a transverse magnetic field. The non‐linear equations governing the flow in the entrance region are solved numerically for various values of Hartmann numbers and the corresponding velocity profiles, pressure distribution and inlet length are obtained. The same method can be applied to other problems of similar nat

ISSN:0044-2267    

DOI:10.1002/zamm.19660460205

出版商:WILEY‐VCH Verlag    

年代:1966

数据来源: WILEY

摘要:

AbstractThe problem of solving two‐dimensional, non‐isothermal, non‐Newtonian boundary layer flow is of great importance in treating ablation phenomena of glassy substances. Many organic or inorganic glassy materials are shear thinning especially when they contain gas bubbles. The liquid layer equations for viscous non‐Newtonian flow are integrated in the vicinity of the stagnation point, when non‐Newtonian flow deviations are caused by shear as well as by the pressure gradient. Numerical results for an ablating model substance with the physical properties of a silicaborate glass (Pyrex) but varying shear rate dependency are given at several

ISSN:0044-2267    

DOI:10.1002/zamm.19660460206

出版商:WILEY‐VCH Verlag    

年代:1966

数据来源: WILEY

摘要:

AbstractThe object of this mote is to find the explicit form of the interpolatory polynomials when their values together with their Mthderivatives are prescribed in the roots of unity. We also study their convergence behaviour and show that the Dini‐Lipschitz condition is sufficient for convergenc

ISSN:0044-2267    

DOI:10.1002/zamm.19660460207

出版商:WILEY‐VCH Verlag    

年代:1966

数据来源: WILEY

摘要:

AbstractA slow stationary motion of a uniformly flowing viscous liquid in the presence of a porous sphere is considered. First it is assumed that the filtration coefficient has constant values for r ϵ (O, b) and r ϵ (b, a) and that Darcy's law holds in the porous medium. Next, the problem of motion is discussed for the case where the sphere is homogeneous yet the initial value of the gradient exists.The formulae obtained for the forces acting on the sphere generalize the results obtained previously for a porous homogeneous sphere under the validity of Darcy's la

ISSN:0044-2267    

DOI:10.1002/zamm.19660460208

出版商:WILEY‐VCH Verlag    

年代:1966

数据来源: WILEY

摘要:

AbstractThe apparent elasticities of an isotropic elastic material in undistorted states are obtained from the second‐order elasticity theory. The results are applied to find the second‐order change of volume for an isotropic body free from external loads. In particular, the requirement that the material is hyperelastic is shown to be equivalent to Zener's form

ISSN:0044-2267    

DOI:10.1002/zamm.19660460209

出版商:WILEY‐VCH Verlag    

年代:1966

数据来源: WILEY

ISSN:0044-2267    

DOI:10.1002/zamm.19660460210

出版商:WILEY‐VCH Verlag    

年代:1966

数据来源: WILEY

ISSN:0044-2267    

DOI:10.1002/zamm.19660460211

出版商:WILEY‐VCH Verlag    

年代:1966

数据来源: WILEY