Mercurial > repos > public > sbplib

view +sbp/+implementations/d1_upwind_5.m @ 1031:2ef20d00b386 feature/advectionRV

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
For easier comparison, return both the first order and residual viscosity when evaluating the residual. Add the first order and residual viscosity to the state of the RungekuttaRV time steppers
author Vidar Stiernström <vidar.stiernstrom@it.uu.se>
date Thu, 17 Jan 2019 10:25:06 +0100
parents f7ac3cd6eeaa
children
line wrap: on
line source

function [H, HI, Dp, Dm, e_1, e_m] = d1_upwind_5(m,h)
    
    if(m<8)
        error('Operator requires at least 8 grid points');
    end

    Hv=ones(m,1);
    Hv(1:4)=[0.251e3/0.720e3; 0.299e3/0.240e3; 0.211e3/0.240e3; 0.739e3/0.720e3;];
    Hv(m-3:m)=rot90(Hv(1:4),2);
    Hv = Hv*h;
    H = spdiag(Hv,0);
    HI = spdiag(1./Hv,0);

    q_diags   = [-2 -1 0 1 2 3];
    q_stencil = [1/20 -1/2 -1/3 +1 -1/4 +1/30];
    Qp = stripeMatrix(q_stencil, q_diags,m);

    Q_U = [
        -0.1e1/0.120e3 0.941e3/0.1440e4 -0.47e2/0.360e3 -0.7e1/0.480e3;
        -0.869e3/0.1440e4 -0.11e2/0.120e3 0.25e2/0.32e2 -0.43e2/0.360e3;
        0.29e2/0.360e3 -0.17e2/0.32e2 -0.29e2/0.120e3 0.1309e4/0.1440e4;
        0.1e1/0.32e2 -0.11e2/0.360e3 -0.661e3/0.1440e4 -0.13e2/0.40e2;
    ];

    Qp(1:4,1:4)=Q_U;
    Qp(m-3:m,m-3:m)=rot90( Q_U(1:4,1:4) ,2 )'; %%% This is different from standard SBP

    Qm=-Qp';

    e_1=sparse(m,1);e_1(1)=1;
    e_m=sparse(m,1);e_m(m)=1;

    Dp=HI*(Qp-1/2*(e_1*e_1')+1/2*(e_m*e_m')) ;

    Dm=HI*(Qm-1/2*(e_1*e_1')+1/2*(e_m*e_m')) ;
end