/[ascend]/trunk/models/steam/dsgsat2.a4c
ViewVC logotype

Contents of /trunk/models/steam/dsgsat2.a4c

Parent Directory Parent Directory | Revision Log Revision Log


Revision 1109 - (show annotations) (download) (as text)
Thu Jan 11 04:07:02 2007 UTC (15 years, 7 months ago) by johnpye
File MIME type: text/x-ascend
File size: 6646 byte(s)
Added some more user error messages from the solver.
Added detection for the MFGRAPH library, which will be used to output GraphViz files based on the incidence matrix.
1 REQUIRE "ivpsystem.a4l";
2 REQUIRE "atoms.a4l";
3 REQUIRE "johnpye/thermo_types.a4c";
4
5 IMPORT "johnpye/extpy/extpy";
6 IMPORT "johnpye/solve";
7 IMPORT "johnpye/solvernotes";
8
9 (*
10 This model uses some ASCEND models from the freesteam library. See
11 http://freesteam.sf.net/ for more information. This model doesn't actually
12 require compiled binaries of freesteam, so you can just download the .a4c
13 files if you wish.
14 *)
15 REQUIRE "steam/satsteamstream.a4c";
16
17 MODEL dsgsat2;
18 n IS_A integer_constant;
19 n :== 5;
20
21 (* temporal derivatives *)
22 drho_dt[2..n] IS_A density_rate;
23 dmdot_dt[2..n] IS_A mass_rate_rate;
24 drhou_dt[2..n] IS_A power_per_volume;
25 dTw_dt[2..n] IS_A temperature_rate;
26
27 (* wall properties *)
28 rho_w IS_A mass_density;
29 D, D_2 IS_A distance;
30 c_w IS_A specific_heat_capacity;
31 A, A_w IS_A area;
32 h_int IS_A heat_transfer_coefficient; (* internal *)
33 h_ext IS_A heat_transfer_coefficient; (* external *)
34 A = 1{PI}*D^2/4;
35 A_w = 1{PI}*(D_2^2 - D^2)/4;
36 dz IS_A distance;
37 L IS_A distance;
38 dz = L / n;
39
40 (* fluid properties *)
41 node[1..n] IS_A satsteamstream;
42
43 (* flow properties *)
44 vel[1..n] IS_A speed;
45 T_w[1..n] IS_A temperature;
46
47 (* constants, for the moment: *)
48 f IS_A positive_factor;
49 mu_f IS_A viscosity;
50 T_amb IS_A temperature;
51
52 (* system dynamics *)
53 qdot_t[2..n], qdot_l[2..n] IS_A power_per_length;
54 qdot_s IS_A power_per_length;
55 rhou[1..n] IS_A energy_per_volume;
56
57 FOR i IN [1..n] CREATE
58 vel[i] = node[i].v*node[i].mdot/A;
59 rhou[i] = node[i].rho * node[i].u;
60 END FOR;
61
62 (* some aliases just for easier review of the state of the model *)
63 x[1..n] IS_A fraction;
64 mdot[1..n] IS_A mass_rate;
65 p[1..n] IS_A pressure;
66 FOR i IN [1..n] CREATE
67 x[i], node[i].x ARE_THE_SAME;
68 mdot[i], node[i].mdot ARE_THE_SAME;
69 p[i], node[i].p ARE_THE_SAME;
70 END FOR;
71
72 (* differential equations *)
73 FOR i IN [2..n] CREATE
74 z_massbal[i]: A * drho_dt[i] = - (node[i].mdot - node[i-1].mdot)/dz;
75 z_mombal[i]: 1/A*dmdot_dt[i] = -(node[i].p-node[i-1].p)/dz
76 - f/D/2*node[i].rho*node[i].v^2*(
77 node[i].rho*vel[i]^2 - node[i-1].rho*vel[i-1]^2
78 )/dz;
79 z_enbal[i]: A * drhou_dt[i] = qdot_t[i] - (node[i].Hdot - node[i-1].Hdot)/dz;
80 z_wall[i]: rho_w*A_w*c_w*dTw_dt[i] = qdot_s - qdot_l[i] - qdot_t[i];
81 z_loss[i]: qdot_l[i] = h_ext*(1{PI}*D_2)*(T_w[i] - T_amb);
82 z_trans[i]: qdot_t[i] = h_int*(1{PI}*D) *(T_w[i] - node[i].T);
83 END FOR;
84
85 t IS_A time;
86 METHODS
87 METHOD on_load;
88 RUN configure_onload;
89 EXTERNAL solve(SELF);
90 RUN configure_steady;
91 END on_load;
92 (*----------------------- a reliable on-load configuration -------------------*)
93 METHOD configure_onload;
94 RUN default_self;
95 RUN reset;
96 RUN bound_self;
97 RUN values;
98 RUN ode_init;
99 EXTERNAL solve(SELF);
100 END configure_onload;
101 METHOD default_self;
102 A := 5 {cm^2};
103 FOR i IN [1..n] DO
104 RUN node[i].default_self;
105 mdot[i] := 0.001 {kg/s};
106 vel[i] := 0.01 {m/s};
107 x[i] := 0.1;
108 END FOR;
109 END default_self;
110 METHOD specify;
111 (* put the model in a state that we are sure it will solve: no big blocks, etc *)
112 RUN ClearAll;
113 FOR i IN [1..n] DO
114 RUN node[i].specify;
115 FIX dTw_dt[i]; FREE T_w[i];
116 FREE rhou[i];
117 END FOR;
118 FIX qdot_s;
119 FIX D, D_2, L;
120 FIX h_int, c_w, rho_w, h_ext;
121 FIX f, mu_f;
122 FIX T_amb;
123 END specify;
124 METHOD values;
125 node[1].T := 424.98 {K};
126 node[1].x := 0.1;
127 qdot_s := 0 {W/m};
128 D := 60 {mm}; D_2 := 70 {mm};
129 L := 100 {m};
130 A_w := 1{PI}*D_2^2;
131 h_int := 10 {W/m^2/K}; c_w := 0.47 {J/g/K}; rho_w := 7.8 {g/cm^3}; h_ext := 10 {W/m^2/K};
132 f := 0.005; mu_f := 4.5e-5 {Pa*s};
133 T_amb := 300 {K};
134 FOR i IN [2..n] DO
135 drho_dt[i] := 0 {kg/m^3/s};
136 dmdot_dt[i] := 0 {kg/s/s};
137 drhou_dt[i] := 0 {kJ/m^3/s};
138 dTw_dt[i] := 0 {K/s};
139 END FOR;
140 t := 0 {s};
141 END values;
142 METHOD bound_self;
143 vel[1..n].upper_bound := 100 {m/s};
144 FOR i IN [1..n] DO
145 RUN node[i].bound_self;
146 END FOR;
147 END bound_self;
148 (*---------------- a physically sensible steady-state configuration-----------*)
149 METHOD configure_steady;
150 RUN ClearAll;
151 RUN specify_steady;
152 RUN values_steady;
153 END configure_steady;
154 METHOD specify_steady;
155 (* change to a proper steady-state problem, with fluid properties FREEd *)
156 FOR i IN [1..n] DO
157 RUN node[i].specify;
158 FIX dTw_dt[i]; FREE T_w[i];
159 FREE rhou[i];
160 END FOR;
161 FIX node[1].p;
162 FREE node[1].T;
163 FIX qdot_s;
164 FIX D, D_2, L;
165 FIX h_int, c_w, rho_w, h_ext;
166 FIX f, mu_f;
167 FIX T_amb;
168 (* fix derivatives to zero *)
169 FOR i IN [2..n] DO
170 (* FIX dmdot_dt[i]; FREE node[i].mdot; *)
171 FREE node[i].x; FIX node[i].p;
172 FIX drho_dt[i]; FREE node[i].p;
173 FIX drhou_dt[i]; FREE node[i].T;
174 FREE mdot[i]; FIX dmdot_dt[i];
175 END FOR;
176 END specify_steady;
177 METHOD values_steady;
178 node[1].p := 5 {bar};
179 FOR i IN [2..n] DO
180 dmdot_dt[i] := 0.0 {kg/s/s};
181 node[i].v := 0.2 {L/kg};
182 node[i].rho := 6 {kg/L};
183 END FOR;
184 (* nothing atm *)
185 END values_steady;
186 (*------------------------- the dynamic problem ------------------------------*)
187 METHOD fixed_pressures;
188 RUN ClearAll;
189 RUN specify;
190 FOR i IN [1..n] DO
191 FREE node[i].T;
192 FIX node[i].p;
193 node[i].p := 5 {bar};
194 FREE node[i].x;
195 FIX dmdot_dt[i];
196 (*
197 FIX dmdot_dt[i];
198 FREE node[i].x;
199 dmdot_dt[i] := 0 {kg/s/s};*)
200 END FOR;
201 END fixed_pressures;
202 METHOD fixed_states;
203 qdot_s := 10 {W/m};
204 FOR i IN [2..n] DO
205 FREE drho_dt[i]; FIX node[i].rho;
206 FREE dmdot_dt[i]; FIX node[i].mdot;
207 FREE drhou_dt[i]; FIX rhou[i];
208 FREE dTw_dt[i]; FIX T_w[i];
209 END FOR;
210 END fixed_states;
211 METHOD fixed_derivs;
212 FOR i IN [2..n] DO
213 FIX drho_dt[i]; FREE node[i].rho;
214 FIX dmdot_dt[i]; FREE node[i].mdot;
215 FIX drhou_dt[i]; FREE rhou[i];
216 FIX dTw_dt[i]; FREE T_w[i];
217 END FOR;
218 END fixed_derivs;
219 METHOD ode_init;
220 (* add the necessary meta data to allow solving with the integrator *)
221 t.ode_type := -1;
222 t.obs_id := 1;
223
224 FOR i IN [2..n] DO
225 drho_dt[i].ode_id := 4*i; node[i].rho.ode_id := 4*i;
226 drho_dt[i].ode_type := 2; node[i].rho.ode_type := 1;
227
228 dmdot_dt[i].ode_id := 4*i+1; node[i].mdot.ode_id := 4*i+1;
229 dmdot_dt[i].ode_type := 2; node[i].mdot.ode_type := 1;
230
231 drhou_dt[i].ode_id := 4*i+2; rhou[i].ode_id := 4*i+2;
232 drhou_dt[i].ode_type := 2; rhou[i].ode_type := 1;
233
234 dTw_dt[i].ode_id := 4*i+3; T_w[i].ode_id := 4*i+3;
235 dTw_dt[i].ode_type := 2; T_w[i].ode_type := 1;
236 END FOR;
237
238 FOR i IN [1..n] DO
239 p[i].obs_id := 1 + 4*i;
240 x[i].obs_id := 2 + 4*i+1;
241 END FOR;
242 FOR i IN [] DO
243 (* qdot_t[i].obs_id := 3 + 4*i; *)
244 node[i].mdot.obs_id := 3 + 4*i;
245 T_w[i].obs_id := 4 + 4*i;
246 END FOR;
247 END ode_init;
248
249 METHOD fix_outlet_quality;
250 FIX x[n];
251 FREE node[1].mdot;
252 END fix_outlet_quality;
253
254 METHOD reinit;
255 RUN on_load;
256 EXTERNAL solve(SELF);
257 RUN fixed_states;
258 END reinit;
259
260 END dsgsat2;
261 ADD NOTES IN dsgsat2;
262 'QRSlv' iterationlimit {50}
263 END NOTES;

Properties

Name Value
svn:executable *

john.pye@anu.edu.au
ViewVC Help
Powered by ViewVC 1.1.22