lbm程序.doc

/* This is a standard two dimensional lattice Boltzmann program with periodic boundary conditions that should perform reasonably efficiently. It has been written for teaching purposes by Alexander Wagner at NDSU (March 2003). Extended to simulate the motion of one particle (March 2005). */ #include stdio.h #include stdlib.h #include string.h #include unistd.h /* for the sleep function. this may not be standard */ #include math.h #include mygraph.h #define xdim 31 #define ydim 21 #define DEBUG double f0[xdim][ydim], f1[xdim][ydim],f2[xdim][ydim],f3[xdim][ydim],f4[xdim][ydim], f5[xdim][ydim],f6[xdim][ydim],f7[xdim][ydim],f8[xdim][ydim]; #ifdef DEBUG double b1[xdim][ydim],b3[xdim][ydim],b5[xdim][ydim],b6[xdim][ydim], bb[xdim][ydim]; #endif double omega=1; /* Some constants that appear often and dont need to be calculated over and over again. So we calculate them just once here. */ double fourOnine=4.0/9.0, oneOnine=1.0/9.0, oneOthirtysix=1.0/36.0; /* Some variables for the suspended particle */ typedef double *doublep; typedef doublep pair[2]; pair *Bf1=NULL,*Bf3=NULL,*Bf5=NULL,*Bf6=NULL; int Bf1c,Bf1m=0,Bf3c,Bf3m=0,Bf5c,Bf5m=0,Bf6c,Bf6m=0; double Cx=15,Cy=10,Mx=0,My=0,Zxx=0,Zxy=0,Zyy=0,Ux=0,Uy=0,R=5,M=100; int Repeat=1,iterations=0,FrequencyMeasure=100,Graphics=1; int Pause=1,sstep=0,done=0; double Amp=0.001,Amp2=0.1,Width=10; /* Some special data types that are required to view the graphics */ int Xdim=xdim,Ydim=ydim,noreq; double rho[xdim][ydim]; int rhoreq=0; double u[xdim][ydim][2]; int ureq=0; void BCmem(pair **p, int c, int *cm){ if (c*cm-2) return; *cm+=100; *p=(pair *) realloc(*p,*cm*sizeof(pair)); } void circleBC(){ /* Sets up the links that are cut by a circular object. */ int x,y,Px,Py,Pxp,Pyp,R2; double dx,dy; #ifdef DEBUG for (x=0;xxdim;x++) for (y=0;yydim;y++) b1[x][y]=b3[x][y]=b5[x][y]=b6[x][y]=bb[x][y]=0; #endif Bf1c=Bf3c=Bf5c=Bf6c=0; R2=R*R; for (x=Cx-R-2;xCx+R+2;x++){ Px=(x+xdim)%xdim; Pxp=(x