write_avs_field_file.c

一个关于LB的经典程序。希望大家有好的东东就那出来

#include "global.h"
#include "defines.h"

void write_avs_field_file(int t)
{
	int 	x,y;
	char 	name[200], RE[10],dummy=(char)12;
	int 	Re;
	float 	u,v,w=0.0,rho,
			min_xx=0.0,
			max_xx=(float)max_x,
 			min_yy=0.0,
			max_yy=(float)max_y,
 			min_zz=0.0,
			max_zz=1.0;

	FILE *fp=NULL;
	
	/* Reynolds number ? */
	Re=(int)((max_y-1)*u_0/((2.0*tau-1.0)/6.0)+0.5);
	
	strcpy(name,"DC.");
	sprintf(RE,"%d",Re);
	strcat(name,RE);
	strcat(name,".");
	sprintf(RE,"%d",t);
	strcat(name,RE);
	strcat(name,".fld");
	
	fp = fopen(name,"w");

	if (fp==(FILE*)NULL)
	{
		printf("error opening %s\n",name);
		exit(0);
	}
	fprintf(fp,"# AVS field file\n");
	fprintf(fp,"#\n");
	fprintf(fp,"ndim=2\n");
	fprintf(fp,"dim1=%d\n",max_x);
	fprintf(fp,"dim2=%d\n",max_y);
	fprintf(fp,"nspace=2\n");
	fprintf(fp,"veclen=3\n");
	fprintf(fp,"data=float\n");
	fprintf(fp,"field=uniform\n");
	fprintf(fp,"min_ext=%f %f\n",min_xx,min_yy);
	fprintf(fp,"max_ext=%f %f\n",max_xx,max_yy);


	putc(dummy,fp);
	putc(dummy,fp);

	for(y=0;y<max_y;y++)
	{
		for(x=0;x<max_x;x++)
		{
			rho=(float)(f[1][y][x]+f[2][y][x]+f[3][y][x]+f[4][y][x]+f[5][y][x]+f[6][y][x]+f[7][y][x]+f[8][y][x]+f[0][y][x]);

			u=(float)(faktor*((f[1][y][x]-f[3][y][x]+f[5][y][x]+f[8][y][x]-f[6][y][x]-f[7][y][x])/rho));
			v=(float)(faktor*((f[2][y][x]-f[4][y][x]+f[5][y][x]+f[6][y][x]-f[7][y][x]-f[8][y][x])/rho));
			fwrite(&u,sizeof(float),1,fp);
			fwrite(&v,sizeof(float),1,fp);
			
			rho=(float)((rho-rho_0)/3.0);
			fwrite(&rho,sizeof(float),1,fp);
		}
	}
	fwrite(&min_xx,sizeof(float),1,fp);
	fwrite(&max_xx,sizeof(float),1,fp);
	fwrite(&min_yy,sizeof(float),1,fp);
	fwrite(&max_yy,sizeof(float),1,fp);

	fclose(fp);	
	printf("wrote %s\n",name);
}