This paper presents a study of visco-elastic flow of an incompressible generalized Oldroyd-B fluid between two infinite parallel plates in which the constitutive equation involves fractional order time derivative. The...This paper presents a study of visco-elastic flow of an incompressible generalized Oldroyd-B fluid between two infinite parallel plates in which the constitutive equation involves fractional order time derivative. The solutions of field equations are being obtained for the motion of the said fluid between two parallel plates where the lower plate starts to move with steady velocity and the upper plate remains fixed in the first problem and the upper plate oscillates with constant frequency and the other being at rest in the second problem. The exact solutions for the velocity field are obtained by using the Laplace transform and finite Fourier Sine transform technique in terms of Mittag Leffler and generalised functions. The analytical expression for the velocity fields are derived and the effect of fractional parameters upon the velocity field is depicted graphically.展开更多
This article considers the existence of solution for a boundary value problem of fractional order, involving Caputo＇s derivative{C0D^δtu（t）=g（t,u（t））,0〈t〈1,1〈δ〈2,u（0）α≠0,u（1）=β≠0.
The velocity field of generalized second order fluid with fractional anomalous diiusion caused by a plate moving impulsively in its own plane is investigated and the anomalous diffusion problems of the stress field an...The velocity field of generalized second order fluid with fractional anomalous diiusion caused by a plate moving impulsively in its own plane is investigated and the anomalous diffusion problems of the stress field and vortex sheet caused by this process are studied. Many previous and classical results can be considered as particular cases of this paper, such as the solutions of the fractional diffusion equations obtained by Wyss; the classical Rayleigh’s time-space similarity solution; the relationship between stress field and velocity field obtained by Bagley and co-worker and Podlubny’s results on the fractional motion equation of a plate. In addition, a lot of significant results also are obtained. For example, the necessary condition for causing the vortex sheet is that the time fractional diffusion index β must be greater than that of generalized second order fluid α; the establiihment of the vorticity distribution function depends on the time history of the velocity profile at a given point, and the time history can be described by the fractional calculus.展开更多
求解了含Caputo分数阶导数的分数阶微分方程初值问题 d~αu/dtα+ω~αu(t;α)=h(t),t>0,0≤n-1<α≤n,ω>0, u^(k)(0^+;α)=u_k,k=0,1,…,n-1.利用Laplace变换方法和广义 Mittag-Leffler函数,得到其解为u(t;α)=integral from...求解了含Caputo分数阶导数的分数阶微分方程初值问题 d~αu/dtα+ω~αu(t;α)=h(t),t>0,0≤n-1<α≤n,ω>0, u^(k)(0^+;α)=u_k,k=0,1,…,n-1.利用Laplace变换方法和广义 Mittag-Leffler函数,得到其解为u(t;α)=integral from n=0 to t (r^(α-1)E_α,α(-(ωτ)~α))h(t-τ)dτ+sum from k=0 to n-1 u_kt^kE_(α,1+k)(-(ωt)~α)。展开更多
文摘This paper presents a study of visco-elastic flow of an incompressible generalized Oldroyd-B fluid between two infinite parallel plates in which the constitutive equation involves fractional order time derivative. The solutions of field equations are being obtained for the motion of the said fluid between two parallel plates where the lower plate starts to move with steady velocity and the upper plate remains fixed in the first problem and the upper plate oscillates with constant frequency and the other being at rest in the second problem. The exact solutions for the velocity field are obtained by using the Laplace transform and finite Fourier Sine transform technique in terms of Mittag Leffler and generalised functions. The analytical expression for the velocity fields are derived and the effect of fractional parameters upon the velocity field is depicted graphically.
基金Supported by the National 973-Project from MOST and Trans-Century Training Programme Foundation for the Talents by Ministry of Education and the Postdoctoral Foundation of China.
文摘This article considers the existence of solution for a boundary value problem of fractional order, involving Caputo＇s derivative{C0D^δtu（t）=g（t,u（t））,0〈t〈1,1〈δ〈2,u（0）α≠0,u（1）=β≠0.
基金the Doctoral Program Foundation of the Education Ministry of China the National Natural Science Foundation of China (Grant No. 10002003) Foundation for University Key Teacher by the Ministry of Education of China.
文摘The velocity field of generalized second order fluid with fractional anomalous diiusion caused by a plate moving impulsively in its own plane is investigated and the anomalous diffusion problems of the stress field and vortex sheet caused by this process are studied. Many previous and classical results can be considered as particular cases of this paper, such as the solutions of the fractional diffusion equations obtained by Wyss; the classical Rayleigh’s time-space similarity solution; the relationship between stress field and velocity field obtained by Bagley and co-worker and Podlubny’s results on the fractional motion equation of a plate. In addition, a lot of significant results also are obtained. For example, the necessary condition for causing the vortex sheet is that the time fractional diffusion index β must be greater than that of generalized second order fluid α; the establiihment of the vorticity distribution function depends on the time history of the velocity profile at a given point, and the time history can be described by the fractional calculus.
文摘求解了含Caputo分数阶导数的分数阶微分方程初值问题 d~αu/dtα+ω~αu(t;α)=h(t),t>0,0≤n-1<α≤n,ω>0, u^(k)(0^+;α)=u_k,k=0,1,…,n-1.利用Laplace变换方法和广义 Mittag-Leffler函数,得到其解为u(t;α)=integral from n=0 to t (r^(α-1)E_α,α(-(ωτ)~α))h(t-τ)dτ+sum from k=0 to n-1 u_kt^kE_(α,1+k)(-(ωt)~α)。
基金Supported by the National Natural Science Foundation of China(11871064)the Graduate Research and Innovation Projects of Jiangsu Province(Yangzhou University)(XKYCX20_010)。
