Velocity Measurement Experiment(속도실험 레포트)

목차

1. Velocity field
1) matlab code
2) 실린더 뒤쪽의 grid에서 속도 벡터를 나타내었다.

2. Mean Recirculation Region
1) Mean Recirculation Region 의 길이.
2) Mean Recirculation Region 길이의 의미

3. Reynolds Number
1) Reynolds Number 구하기
2) u∞ 값의 선정 근거

4. Vorticity Field
1) matlab code
2) 순간 속도장의 vorticity field와의 비교

5. Stream Line
1) matlab code
2) 순간 속도장의 stream line 과의 비교

7. 참고자료 grid 및 기본 상수 (프로그램에 사용)

8. 소감

9. references

10. CODE
1. gen_timeaveraged.cpp ; 속도 벡터를 시간에 대해 평균
2.gen_vorticity.cpp ; vorticity를 구함
3.gen_position_vel.cpp ; 위치와 속도 벡터를 정리

본문내용

);
}
/*** data name function ***/
/*** file name form : from 070001.vec to 070300.vec ***/
char * ntos (int n) {
char * re;
re = (char *)malloc(sizeof(char)*11);
re[0] = '0';
re[1] = '7';
re[2] = '0';
re[6] = '.';
re[7] = 'v';
re[8] = 'e';
re[9] = 'c';
re[10] = '\0';
if(n < 10) {
re[3] = '0';
re[4] = '0';
re[5] = (char)(n+48);
} else if(n >= 10 && n < 100) {
re[3] = '0';
re[4] = (char)(n/10+48);
re[5] = (char)(n%10+48);
} else if(n >= 100 && n < 1000) {
re[3] = (char)(n/100+48);
n = n%100;
re[4] = (char)(n/10+48);
re[5] = (char)(n%10+48);
}
return re;
}
2.gen_vorticity.cpp ; vorticity를 구함
/***********************************************/
/* */
/* VORTICITY PROGRAM BY TIME-AVERAGED DATA */
/* */
/***********************************************/
#include
#define dx 1.59
#define dy 1.60
void main() {
FILE *in_Xpos,*in_Ypos,*in_Xvel,*in_Yvel;
FILE *out_X2pos,*out_Y2pos,*out_Vor;
int i,j;
double tmp;
double X[14],Y[14],u[14][14],v[14][14],v_x[12][12],u_y[12][12];
/*** LOADING DATA ***/
in_Xpos = fopen("X.txt","r");
in_Ypos = fopen("Y.txt","r");
in_Xvel = fopen("u.txt","r");
in_Yvel = fopen("v.txt","r");
/*** INITIALIZING ***/
for (i=0;i<14;i++) {
fscanf(in_Xpos,"%le",&tmp);X[i]=tmp;
fscanf(in_Ypos,"%le",&tmp); Y[i]=tmp;
for (j=0;j<14;j++) {
if(j!=0) fscanf(in_Ypos,"%le",&tmp);
fscanf(in_Xvel,"%le",&tmp);u[i][j]=tmp;
fscanf(in_Yvel,"%le",&tmp); v[i][j]=tmp;
}
}
/*** dv/dx , du/dy ***/
for (i=0;i<12;i++) {
for (j=0;j<12;j++) {
v_x[i][j]=(v[i+1][j+2]-v[i+1][j])/(2*dx);
u_y[i][j]=(u[i+2][j+1]-u[i][j+1])/(2*dy);
}
}
/*** WRITING DATAFILE ***/
out_X2pos = fopen("X2.txt","w");
out_Y2pos = fopen("Y2.txt","w");
out_Vor = fopen("vorticity.txt","w");
for (i=0;i<12;i++) {
for (j=0;j<12;j++) {
fprintf(out_X2pos,"%13f",X[j+1]);
fprintf(out_Y2pos,"%13f",Y[i+1]);
fprintf(out_Vor,"%13f",v_x[i][j]-u_y[i][j]);
if (j==11)
{
fprintf(out_X2pos,"\n");
fprintf(out_Vor,"\n");
fprintf(out_Y2pos,"\n");
}
}
}
printf("DONE\n");
printf("X2.txt\nY2.txt\nvorticity.txt\nare generated.\n");
}
3.gen_position_vel.cpp ; 위치와 속도 벡터를 정리
#include
void main(void) {
FILE *in_Xpos,*in_Ypos,*out_Xpos,*out_Ypos;
FILE *in_Xvel,*in_Yvel,*out_Xvel,*out_Yvel;
int i,j;
double tmpX,tmpY;
in_Xpos = fopen("X.txt","r");
in_Ypos = fopen("Y.txt","r");
out_Xpos = fopen("Xmono.txt","w");
out_Ypos = fopen("Ymono.txt","w");
for (i=0;i<196;i++) {
if(i<14)
{fscanf(in_Xpos,"%le",&tmpX);
fprintf(out_Xpos,"%.7f\n",tmpX);
}
fscanf(in_Ypos,"%le",&tmpY);
if(i%14==0) fprintf(out_Ypos,"%.7f\n",tmpY);
}
fclose(in_Xpos);
fclose(in_Ypos);
fclose(out_Xpos);
fclose(out_Ypos);
printf("DONE : position \n");
in_Xvel = fopen("u.txt","r");
in_Yvel = fopen("v.txt","r");
out_Xvel = fopen("umatrix.txt","w");
out_Yvel = fopen("vmatrix.txt","w");
for (i=0;i<14;i++) {
for (j=0;j<14;j++) {
fscanf(in_Xvel,"%le",&tmpX);
fscanf(in_Yvel,"%le",&tmpY);
fprintf(out_Xvel,"%13.7f",tmpX);
fprintf(out_Yvel,"%13.7f",tmpY);
if (j%14==13)
{
fprintf(out_Xvel,"\n");
fprintf(out_Yvel,"\n");
}
}
}
printf("DONE : velocity\n");
}

키워드

Velocity Measurement Experiment,   PIV,   Velocity field ,   Mean Recirculation Region,   matlab code,   Reynolds Number ,   순간 속도장의 vorticity field와의 비교 ,   Stream Line