-
Notifications
You must be signed in to change notification settings - Fork 2
/
Copy pathground.c
329 lines (271 loc) · 7.04 KB
/
ground.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
/*** Translated to the C language by N. Kyriazis 20 Aug 2003 ***
Program NEC(input,tape5=input,output,tape11,tape12,tape13,tape14,
tape15,tape16,tape20,tape21)
Numerical Electromagnetics Code (NEC2) developed at Lawrence
Livermore lab., Livermore, CA. (contact G. Burke at 415-422-8414
for problems with the NEC code. For problems with the vax implem-
entation, contact J. Breakall at 415-422-8196 or E. Domning at 415
422-5936)
file created 4/11/80.
***********Notice**********
This computer code material was prepared as an account of work
sponsored by the United States government. Neither the United
States nor the United States Department Of Energy, nor any of
their employees, nor any of their contractors, subcontractors,
or their employees, makes any warranty, express or implied, or
assumes any legal liability or responsibility for the accuracy,
completeness or usefulness of any information, apparatus, product
or process disclosed, or represents that its use would not infringe
privately-owned rights.
*******************************************************************/
#include "nec2c.h"
#include "shared.h"
/*-------------------------------------------------------------------*/
/* segment to obtain the total field due to ground. the method of */
/* variable interval width romberg integration is used. there are 9 */
/* field components - the x, y, and z components due to constant, */
/* sine, and cosine current distributions. */
void rom2( double a, double b, complex double *sum, double dmin )
{
int i, ns, nt, flag=TRUE;
int nts = 4, nx = 1, n = 9;
double ze, ep, zend, dz=0., dzot=0., tmag1, tmag2, tr, ti;
double z, s; /***also global***/
double rx = 1.0e-4;
complex double g1[9], g2[9], g3[9], g4[9], g5[9];
complex double t00, t01[9], t10[9], t02, t11, t20[9];
z= a;
ze= b;
s= b- a;
if( s < 0.)
{
fprintf( output_fp, "\n ERROR - B LESS THAN A IN ROM2" );
stop(-1);
}
ep= s/(1.e4* data.npm);
zend= ze- ep;
for( i = 0; i < n; i++ )
sum[i]=CPLX_00;
ns= nx;
nt=0;
sflds( z, g1);
while( TRUE )
{
if( flag )
{
dz= s/ ns;
if( z+ dz > ze)
{
dz= ze- z;
if( dz <= ep)
return;
}
dzot= dz*.5;
sflds( z+ dzot, g3);
sflds( z+ dz, g5);
} /* if( flag ) */
tmag1=0.;
tmag2=0.;
/* evaluate 3 point romberg result and test convergence. */
for( i = 0; i < n; i++ )
{
t00=( g1[i]+ g5[i])* dzot;
t01[i]=( t00+ dz* g3[i])*.5;
t10[i]=(4.* t01[i]- t00)/3.;
if( i > 2)
continue;
tr= creal( t01[i]);
ti= cimag( t01[i]);
tmag1= tmag1+ tr* tr+ ti* ti;
tr= creal( t10[i]);
ti= cimag( t10[i]);
tmag2= tmag2+ tr* tr+ ti* ti;
} /* for( i = 0; i < n; i++ ) */
tmag1= sqrt( tmag1);
tmag2= sqrt( tmag2);
test( tmag1, tmag2, &tr, 0., 0., &ti, dmin);
if( tr <= rx)
{
for( i = 0; i < n; i++ )
sum[i] += t10[i];
nt += 2;
z += dz;
if( z > zend)
return;
for( i = 0; i < n; i++ )
g1[i]= g5[i];
if( (nt >= nts) && (ns > nx) )
{
ns= ns/2;
nt=1;
}
flag = TRUE;
continue;
} /* if( tr <= rx) */
sflds( z+ dz*.25, g2);
sflds( z+ dz*.75, g4);
tmag1=0.;
tmag2=0.;
/* evaluate 5 point romberg result and test convergence. */
for( i = 0; i < n; i++ )
{
t02=( t01[i]+ dzot*( g2[i]+ g4[i]))*.5;
t11=( 4.0 * t02- t01[i] )/3.;
t20[i]=(16.* t11- t10[i])/15.;
if( i > 2)
continue;
tr= creal( t11);
ti= cimag( t11);
tmag1= tmag1+ tr* tr+ ti* ti;
tr= creal( t20[i]);
ti= cimag( t20[i]);
tmag2= tmag2+ tr* tr+ ti* ti;
} /* for( i = 0; i < n; i++ ) */
tmag1= sqrt( tmag1);
tmag2= sqrt( tmag2);
test( tmag1, tmag2, &tr, 0.,0., &ti, dmin);
if( tr > rx)
{
nt=0;
if( ns < data.npm )
{
ns= ns*2;
dz= s/ ns;
dzot= dz*.5;
for( i = 0; i < n; i++ )
{
g5[i]= g3[i];
g3[i]= g2[i];
}
flag=FALSE;
continue;
} /* if( ns < npm) */
fprintf( output_fp,
"\n ROM2 -- STEP SIZE LIMITED AT Z = %12.5E", z );
} /* if( tr > rx) */
for( i = 0; i < n; i++ )
sum[i]= sum[i]+ t20[i];
nt= nt+1;
z= z+ dz;
if( z > zend)
return;
for( i = 0; i < n; i++ )
g1[i]= g5[i];
flag = TRUE;
if( (nt < nts) || (ns <= nx) )
continue;
ns= ns/2;
nt=1;
} /* while( TRUE ) */
}
/*-----------------------------------------------------------------------*/
/* sfldx returns the field due to ground for a current element on */
/* the source segment at t relative to the segment center. */
void sflds( double t, complex double *e )
{
double xt, yt, zt, rhx, rhy, rhs, rho, phx, phy;
double cph, sph, zphs, r2s, rk, sfac, thet;
complex double erv, ezv, erh, ezh, eph, er, et, hrv, hzv, hrh;
xt= dataj.xj+ t* dataj.cabj;
yt= dataj.yj+ t* dataj.sabj;
zt= dataj.zj+ t* dataj.salpj;
rhx= incom.xo- xt;
rhy= incom.yo- yt;
rhs= rhx* rhx+ rhy* rhy;
rho= sqrt( rhs);
if( rho <= 0.)
{
rhx=1.;
rhy=0.;
phx=0.;
phy=1.;
}
else
{
rhx= rhx/ rho;
rhy= rhy/ rho;
phx= -rhy;
phy= rhx;
}
cph= rhx* incom.xsn+ rhy* incom.ysn;
sph= rhy* incom.xsn- rhx* incom.ysn;
if( fabs( cph) < 1.0e-10)
cph=0.;
if( fabs( sph) < 1.0e-10)
sph=0.;
gwav.zph= incom.zo+ zt;
zphs= gwav.zph* gwav.zph;
r2s= rhs+ zphs;
gwav.r2= sqrt( r2s);
rk= gwav.r2* TP;
gwav.xx2= cmplx( cos( rk),- sin( rk));
/* use norton approximation for field due to ground. current is */
/* lumped at segment center with current moment for constant, sine, */
/* or cosine distribution. */
if( incom.isnor != 1)
{
gwav.zmh=1.;
gwav.r1=1.;
gwav.xx1=0.;
gwave( &erv, &ezv, &erh, &ezh, &eph);
et=-CONST1* gnd.frati* gwav.xx2/( r2s* gwav.r2);
er=2.* et* cmplx(1.0, rk);
et= et* cmplx(1.0 - rk* rk, rk);
hrv=( er+ et)* rho* gwav.zph/ r2s;
hzv=( zphs* er- rhs* et)/ r2s;
hrh=( rhs* er- zphs* et)/ r2s;
erv= erv- hrv;
ezv= ezv- hzv;
erh= erh+ hrh;
ezh= ezh+ hrv;
eph= eph+ et;
erv= erv* dataj.salpj;
ezv= ezv* dataj.salpj;
erh= erh* incom.sn* cph;
ezh= ezh* incom.sn* cph;
eph= eph* incom.sn* sph;
erh= erv+ erh;
e[0]=( erh* rhx+ eph* phx)* dataj.s;
e[1]=( erh* rhy+ eph* phy)* dataj.s;
e[2]=( ezv+ ezh)* dataj.s;
e[3]=0.;
e[4]=0.;
e[5]=0.;
sfac= PI* dataj.s;
sfac= sin( sfac)/ sfac;
e[6]= e[0]* sfac;
e[7]= e[1]* sfac;
e[8]= e[2]* sfac;
return;
} /* if( smat.isnor != 1) */
/* interpolate in sommerfeld field tables */
if( rho >= 1.0e-12)
thet= atan( gwav.zph/ rho);
else
thet= POT;
/* combine vertical and horizontal components and convert */
/* to x,y,z components. multiply by exp(-jkr)/r. */
intrp( gwav.r2, thet, &erv, &ezv, &erh, &eph );
gwav.xx2= gwav.xx2/ gwav.r2;
sfac= incom.sn* cph;
erh= gwav.xx2*( dataj.salpj* erv+ sfac* erh);
ezh= gwav.xx2*( dataj.salpj* ezv- sfac* erv);
/* x,y,z fields for constant current */
eph= incom.sn* sph* gwav.xx2* eph;
e[0]= erh* rhx+ eph* phx;
e[1]= erh* rhy+ eph* phy;
e[2]= ezh;
/* x,y,z fields for sine current */
rk= TP* t;
sfac= sin( rk);
e[3]= e[0]* sfac;
e[4]= e[1]* sfac;
/* x,y,z fields for cosine current */
e[5]= e[2]* sfac;
sfac= cos( rk);
e[6]= e[0]* sfac;
e[7]= e[1]* sfac;
e[8]= e[2]* sfac;
return;
}
/*-----------------------------------------------------------------------*/