\n\tclc; clear; close;
\ncolormap jet
\nlx=300; ly=60;
\ncs=1\/3^0.5; c_squ=cs^2;
\nt1=4\/9; t2=1\/9; t3=1\/36;
\nRe=100;
\nUin=0.05;
\nnu=(ly-1)*Uin\/Re;
\ntau=3*nu+0.5;
\nomega=1\/tau;
\noppo=[5,6,7,8,1,2,3,4,9];
\nt= [1\/9,1\/36,1\/9,1\/36,1\/9,1\/36,1\/9,1\/36,4\/9];%D2Q9\u6743\u91cd
\nex=[1, 1, 0, -1, -1, -1, 0, 1, 0]; % D2Q9\u65b9\u5411\u5411\u91cf
\ney=[0, 1, 1, 1, 0, -1, -1, -1, 0]; % D2Q9\u65b9\u5411\u5411\u91cf
\nrho=ones(ly,lx);
\nUX=zeros(ly,lx);
\nUX(:,1:lx\/2)=0.1;
\nUY=zeros(ly,lx);
\nF=zeros(ly,lx,9);
\nF=FEQf(UX,UY,rho,t1,t2,t3,c_squ);
\nfor i=1:10000
\nF=stream(F,ly,lx);
\nrho = sum(F,3); <\/span> %\u8ba1\u7b97\u5bc6\u5ea6
\nUX=(sum(F(:,:,[1 2 8]),3)-sum(F(:,:,[4 5 6]),3)).\/rho; %\u8ba1\u7b97x\u901f\u5ea6
\nUY=(sum(F(:,:,[2 3 4]),3)-sum(F(:,:,[6 7 8]),3)).\/rho; %\u8ba1\u7b97y\u901f\u5ea6
\nP=cs^2*rho;
\nUX([1,ly],:)=0;UY([1,ly],:)=0; %\u58c1\u9762
\nUX(:,1)=Uin; UY(:,1)=0; %\u5de6\u5165\u53e3
\nrho(:,1)=rho(:,2);
\nUX(:,lx)=UX(:,lx-1); UY(:,lx)=0; %\u53f3\u51fa\u53e3
\nrho(:,1)=1;
\nFEQ=FEQf(UX,UY,rho,t1,t2,t3,c_squ);
\nFb=F;
\nF=omega*FEQ+(1-omega)*F; %\u78b0\u649e
\nF([1,ly],:,:)=Fb([1,ly],:,oppo);
\nF(:,1,:)=FEQ(:,1,:)+(F(:,2,:)-FEQ(:,2,:));
\nF(:,lx,:)=FEQ(:,lx,:)+(F(:,lx-1,:)-FEQ(:,lx-1,:));
\nif mod(i,20)==0
\nU= (UX.^2+ UY.^2).^0.5;
\nimagesc(U);
\naxis equal
\ndrawnow
\naxis xy
\nend
\nend\n<\/p>\n

\n\tfunction F=stream(F,ly,lx)
\nF(:,:,1)=F(:,[lx 1:lx-1],1);
\nF(:,:,2)=F([ly 1:ly-1], [lx 1:lx-1],2);
\nF(:,:,3)=F([ly 1:ly-1],:,3);
\nF(:,:,4)=F( [ly 1:ly-1], [2:lx 1],4);
\nF(:,:,5)=F(:,[2:lx 1],5);
\nF(:,:,6)=F([2:ly 1], [2:lx 1],6);
\nF(:,:,7)=F([2:ly 1],:,7);
\nF(:,:,8)=F([2:ly 1],[lx 1:lx-1],8);<\/p>\n

function FEQ=FEQf(UX,UY,rho,t1,t2,t3,c_squ)
\n <\/span>U_SQU=UX.^2+UY.^2; U_C2=UX+UY;
\n <\/span>U_C4=-UX+UY; U_C6=-U_C2;
\n <\/span>U_C8=-U_C4;
\n <\/span>FEQ(:,:,1)=t2*rho.*(1+UX\/c_squ+0.5*(UX\/c_squ).^2-U_SQU\/(2*c_squ));
\n <\/span>FEQ(:,:,3)=t2*rho.*(1+UY\/c_squ+0.5*(UY\/c_squ).^2-U_SQU\/(2*c_squ));
\n <\/span>FEQ(:,:,5)=t2*rho.*(1-UX\/c_squ+0.5*(UX\/c_squ).^2-U_SQU\/(2*c_squ));
\n <\/span>FEQ(:,:,7)=t2*rho.*(1-UY\/c_squ+0.5*(UY\/c_squ).^2-U_SQU\/(2*c_squ));
\n <\/span>FEQ(:,:,2)=t3*rho.*(1+U_C2\/c_squ+0.5*(U_C2\/c_squ).^2-U_SQU\/(2*c_squ));
\n <\/span>FEQ(:,:,4)=t3*rho.*(1+U_C4\/c_squ+0.5*(U_C4\/c_squ).^2-U_SQU\/(2*c_squ));
\n <\/span>FEQ(:,:,6)=t3*rho.*(1+U_C6\/c_squ+0.5*(U_C6\/c_squ).^2-U_SQU\/(2*c_squ));
\n <\/span>FEQ(:,:,8)=t3*rho.*(1+U_C8\/c_squ+0.5*(U_C8\/c_squ).^2-U_SQU\/(2*c_squ));
\n <\/span>FEQ(:,:,9)=t1*rho.*(1-U_SQU\/(2*c_squ));<\/p>\n

\n\t\t\n\t<\/div><\/p>\n","protected":false},"excerpt":{"rendered":"