共查询到20条相似文献,搜索用时 31 毫秒
1.
Bidyut Santra Bhabani S. Dandapat 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》2009,60(4):688-700
A thin viscous liquid film flow is developed over a stretching sheet under different nonlinear stretching velocities. An evolution
equation for the film thickness, is derived using long-wave approximation of thin liquid film and is solved numerically by
using the Newton–Kantorovich method. A comparison is made with the analytic solution obtained in [B. S. Dandapat, A. Kitamura,
B. Santra, “Transient film profile of thin liquid film flow on a stretching surface”, ZAMP, 57, 623-635 (2006)]. It is observed that all types of stretching produce film thinning but non-monotonic stretching produces
faster thinning at small distance from the origin. The velocity u along the stretching direction strongly depends on the distance along the stretching direction and the Froude number. 相似文献
2.
B. S. Dandapat Bidyut Santra S. K. Singh 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》2010,46(2):685-695
A thin viscous liquid film flow is developed over a stretching sheet under different non-linear stretching velocities in presence
of uniform transverse magnetic field. Evolution equation for the film thickness is derived using long-wave approximation of
thin liquid film and is solved numerically by using the Newton–Kantorovich method. It is observed that all types of stretching
produces film thinning, but non-monotonic stretching produces faster thinning at small distance from the origin. Effect of
the transverse magnetic field is to slow down the film thinning process. Observed flow behavior is explained physically. 相似文献
3.
B. S. Dandapat Bidyut Santra S. K. Singh 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》2010,61(4):685-695
A thin viscous liquid film flow is developed over a stretching sheet under different non-linear stretching velocities in presence of uniform transverse magnetic field. Evolution equation for the film thickness is derived using long-wave approximation of thin liquid film and is solved numerically by using the Newton–Kantorovich method. It is observed that all types of stretching produces film thinning, but non-monotonic stretching produces faster thinning at small distance from the origin. Effect of the transverse magnetic field is to slow down the film thinning process. Observed flow behavior is explained physically. 相似文献
4.
B. S. Dandapat A. Kitamura B. Santra 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》2006,45(11):623-635
In this paper we have studied a non-planar thin liquid film flow on a planar stretching surface. The stretching surface is
assumed to stretch impulsively from rest and the effect of inertia of the liquid is considered. Equations describing the laminar
flow on the stretching surface are solved analytically. It is observed that faster stretching causes quicker thinning of the
film on the stretching surface. Velocity distribution in the liquid film and the transient film profile as functions of time
are obtained. 相似文献
5.
B. S. Dandapat A. Kitamura B. Santra 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》2006,57(4):623-635
In this paper we have studied a non-planar thin liquid film flow on a planar stretching surface. The stretching surface is
assumed to stretch impulsively from rest and the effect of inertia of the liquid is considered. Equations describing the laminar
flow on the stretching surface are solved analytically. It is observed that faster stretching causes quicker thinning of the
film on the stretching surface. Velocity distribution in the liquid film and the transient film profile as functions of time
are obtained.
(Received: May 4, 2004; revised: February 2/August 24, 2005) 相似文献
6.
This paper presents a mathematical analysis of MHD flow and heat transfer to a laminar liquid film from a horizontal stretching surface. The flow of a thin fluid film and subsequent heat transfer from the stretching surface is investigated with the aid of similarity transformation. The transformation enables to reduce the unsteady boundary layer equations to a system of non-linear ordinary differential equations. Numerical solution of resulting non-linear differential equations is found by using efficient shooting technique. Boundary layer thickness is explored numerically for some typical values of the unsteadiness parameter S and Prandtl number Pr, Eckert number Ec and Magnetic parameter Mn. Present analysis shows that the combined effect of magnetic field and viscous dissipation is to enhance the thermal boundary layer thickness. 相似文献
7.
Á. G. Horváth 《Monatshefte für Mathematik》2007,150(3):211-216
This paper presents a result concerning the connection between the parallel projection P
v,H
of a parallelotope P along the direction v (into a transversal hyperplane H) and the extension P + S(v), meaning the Minkowski sum of P and the segment S(v) = {λv | −1 ≤ λ ≤ 1}. A sublattice L
v
of the lattice of translations of P associated to the direction v is defined. It is proved that the extension P + S(v) is a parallelotope if and only if the parallel projection P
v,H
is a parallelotope with respect to the lattice of translations L
v,H
, which is the projection of the lattice L
v
along the direction v into the hyperplane H. 相似文献
8.
《Quaestiones Mathematicae》2013,36(1):137-151
Abstract In this paper, the steady boundary layer flow of a non-Newtonian fluid over a nonlinear stretching sheet is investigated. The Sisko fluid model, which is combination of power-law and Newtonian fluids in which the fluid may exhibit shear thinning/thickening behaviors, is considered. The boundary layer equations are derived for the two-dimensional flow of an incompressible Sisko fluid. Similarity transformations are used to reduce the governing nonlinear equations and then solved analytically using the homotopy analysis method. In addition, closed form exact analytical solutions are provided for n = 0 and n = 1. Effects of the pertinent parameters on the boundary layer flow are shown and solutions are contrasted with the power-law fluid solutions. 相似文献
9.
10.
We consider a new way of establishing Navier wall laws. Considering a bounded domain Ω of R
N
, N=2,3, surrounded by a thin layer Σ
ε
, along a part Γ2 of its boundary ∂Ω, we consider a Navier-Stokes flow in Ω∪∂Ω∪Σ
ε
with Reynolds’ number of order 1/ε in Σ
ε
. Using Γ-convergence arguments, we describe the asymptotic behaviour of the solution of this problem and get a general Navier
law involving a matrix of Borel measures having the same support contained in the interface Γ2. We then consider two special cases where we characterize this matrix of measures. As a further application, we consider
an optimal control problem within this context. 相似文献
11.
Given a data instanced=(A, b, c) of a linear program, we show that certain properties of solutions along the central trajectory of the linear program are
inherently related to the condition number C(d) of the data instanced=(A, b, c), where C(d) is a scale-invariant reciprocal of a closely-related measure ρ(d) called the “distance to ill-posedness”. (The distance to ill-posedness essentially measures how close the data instanced=(A,b,c) is to being primal or dual infeasible.) We present lower and upper bounds on sizes of optimal solutions along the central
trajectory, and on rates of change of solutions along the central trajectory, as either the barrier parameter μ or the datad=(A, b, c) of the linear program is changed. These bounds are all linear or polynomial functions of certain natural parameters associated
with the linear program, namely the condition number C(d), the distance to ill-posedness ρ(d), the norm of the data ‖d‖, and the dimensionsm andn. 相似文献
12.
E. Momoniat 《Journal of Mathematical Analysis and Applications》2006,322(1):41-50
A second-order non-linear partial differential equation modelling the gravity driven spreading of a thin viscous liquid film with time-dependent non-uniform surface tension Σ(t,r) is considered. The problem is specified in cylindrical polar coordinates where we assume the flow is axisymmetric. Similarity solutions describing the spreading of a thin drop and the flattening of a thin bubble are investigated. 相似文献
13.
Kallol Paul 《Mathematica Slovaca》2010,60(1):121-128
One of the couple of translatable radii of an operator in the direction of another operator introduced in earlier work [PAUL,
K.: Translatable radii of an operator in the direction of another operator, Scientae Mathematicae 2 (1999), 119–122] is studied in details. A necessary and sufficient condition for a unit vector f to be a stationary vector of the generalized eigenvalue problem Tf = λAf is obtained. Finally a theorem of Williams ([WILLIAMS, J. P.: Finite operators, Proc. Amer. Math. Soc. 26 (1970), 129–136]) is generalized to obtain a translatable radius of an operator in the direction of another operator. 相似文献
14.
In this paper we have considered the study of boundary layer flow past a stretching plate in visco-elastic fluid (Walters' liquid B Model).The solution of boundary layer equation of motion past a stretching plate is obtained by using similarity parameter method. The influence of visco-elastic parameterk
0
*
on the flow velocity is investigated.
Zusammenfassung Die Arbeit behandelt die Grenzschichtströmung um eine gespannte Platte in einer viskoelastischen Flüssigkeit (Walters Flüssigkeitsmodell B).Die Lösung der Grenzschicht-Bewegungsgleichung für eine gespannte Platte wird durch die Ähnlichkeits-Parametermethode erzielt. Der Einfluß des viskoelastischen Parametersk 0 * auf die Strömungsgeschwindigkeit wird untersucht.相似文献
15.
Francesc Planas-Vilanova 《manuscripta mathematica》1995,87(1):349-357
For a given idealI of a commutative ringA, B=A/I, the vanishing of the second André-Quillen (co)homology functorH
2
(A, B, δ) is characterized in terms of the canonical homomorphism α:S(I)→R(I) from the symmetric algebra of the idealI onto its Rees algebra. This is done by introducing a Koszul complex that characterizes commutative graded algebras which
are symmetric algebras.
This article was processed by the author using the LATEX style filecljour1 from Springer-Verlag. 相似文献
This article was processed by the author using the LATEX style filecljour1 from Springer-Verlag. 相似文献
16.
Given two sets
A, B í \Bbb Fqd{\cal A}, {\cal B}\subseteq {\Bbb F}_q^d
, the set of d dimensional vectors over the finite field
\Bbb Fq{\Bbb F}_q
with q elements, we show that the sumset
A+B = {a+b | a ? A, b ? B}{\cal A}+{\cal B} = \{{\bf a}+{\bf b}\ \vert\ {\bf a} \in {\cal A}, {\bf b} \in {\cal B}\}
contains a geometric progression of length k of the form vΛ
j
, where j = 0,…, k − 1, with a nonzero vector
v ? \Bbb Fqd{\bf v} \in {\Bbb F}_q^d
and a nonsingular d × d matrix Λ whenever
# A # B 3 20 q2d-2/k\# {\cal A} \# {\cal B} \ge 20 q^{2d-2/k}
. We also consider some modifications of this problem including the question of the existence of elements of sumsets on algebraic
varieties. 相似文献
17.
LetB be a compact convex body symmetric around0 in ℝ2 which has nonempty interior, i.e., the unit ball of a two-dimensional Minkowski space. The self-packing radiusρ(m,B) is the smallestt such thatt
B can be packed withm translates of the interior ofB. Form≤6 we show that the self-packing radiusρ(m,B)=1+2/α(m,B) whereα(m,B) is the Minkowski length of the side of the largest equilateralm-gon inscribed inB (measured in the Minkowski metric determined byB). We showρ(6,B)=ρ(7,B)=3 for allB, and determine most of the largest and smallest values ofρ(m,B) form≤7. For allm we have
相似文献
18.
Giuseppe Da Prato Hélène Frankowska 《NoDEA : Nonlinear Differential Equations and Applications》2006,12(4):481-501
In this paper we consider a stochastic flow in Rn which leaves a closed convex set K invariant. By using a recent characterization of the invariance, involving the distance function, we study the corresponding
transition semigroup Pt and its infinitesimal generator N. Due to the invariance property, N is a degenerate elliptic operator. We study existence of an invariant measure ν of Pt and the realization of N in L2 (H, ν). 相似文献
19.
J. Matoušek 《Discrete and Computational Geometry》2001,25(3):389-403
Motivated by problems from calculus of variations and partial differential equations, we investigate geometric properties
of D-convexity. A function f: R
d → R is called D-convex, where D is a set of vectors in R
d, if its restriction to each line parallel to a nonzero v ∈ D is convex. The D-convex hull of a compact set A ⊂ R
d, denoted by coD(A), is the intersection of the zero sets of all nonnegative D-convex functions that are zero on A. It also equals the zero set of the D-convex envelope of the distance function of A. We give an example of an n-point set A ⊂ R
2 where the D-convex envelope of the distance function is exponentially close to zero at points lying relatively far from co
D(A), showing that the definition of the D-convex hull can be very nonrobust. For separate convexity in R
3 (where D is the orthonormal basis of R
3), we construct arbitrarily large finite sets A with co
D(A) ≠ A whose proper subsets are all equal to their D-convex hull. This implies the existence of analogous sets for rank-one convexity and for quasiconvexity on 3 × 3 (or larger)
matrices.
This research was supported by Charles University Grants No. 158/99 and 159/99. 相似文献
20.
A simplified system of differential equations is applied to analyze the stability under small long-wave perturbations of the inclined flow of a thin layer of a heavy incompressible viscous liquid produced by melting of channel walls in a stream of a hot viscous gas. The flow of the liquid film is shown to be unstable under such perturbations.Translated from Vychislitel'naya i Prikladnaya Matematika, No. 61, pp. 53–58, 1987. 相似文献
|