Several kind of new numerical schemes for the stationary Navier-Stokes equa-tions based on the virtue of Inertial Manifold and Approximate Inertial Manifold, whichwe call them inertial algorithms in this paper, together with their error estimations are pre-sented. All these algorithms are constructed under an uniform frame, that is to constructsome kind of new projections for the Sobolev space in which the true solution is sought.It is shown that the proposed inertial algorithms can greatly improve the convergence rateof the standard Galerkin approximate solution with lower computing effort. And somenumerical examples are also given to verify results of this paper.
In this paper, we consider a linearly elastic shell, I.e. A three-dimensional linearly elastic body with a small thickness denoted by 2ε, which is clamped along its part of the lateral boundary and subjected to the regular loads. In the linear case, one can use the two-dimensional models of Ciarlet or Koiter to calculate the displacement for the shell. Some error estimates between the approximate solution of these models and the three-dimensional displacement vector field of a flexural or membrane shell have been obtained. Here we give a new model for a linear and nonlinear shell, prove that there exists a unique solution U of the two-dimensional variational problem and construct a three-dimensional approximate solutions UKT(x,ξ) in terms of U:{ UKT(x,ξ):=U(x)+П1Uξ+П2Uξ2,П1U=-aαβ*▽βU3→eα-λ0γ0(U)→n,П2U=(1/λ+μ)*▽β(aαβλσ+γλσ(U))-bαβ*▽βU3)→eα+1/2λ0(ρKT0(U)-(1+λ0)Hγ0(U)-2β0(U))→n.We also provide the error estimates between our model and the three-dimensional displacement vector field:‖u-UKT‖1,(Ω)≤Cεr, r=3/2, an elliptic membrane, r=1/2, a general membrane,where C is a constant dependent only upon the data ‖u‖3,Ω, ‖UKT‖3,Ω, →θ.
