models/johnpye/thermalequilibrium2.a4c

REQUIRE "ivpsystem.a4l";
REQUIRE "johnpye/thermo_types.a4c";

IMPORT "freesteam";
IMPORT "johnpye/extpy/extpy";
IMPORT "johnpye/listnotes";

MODEL simple_state;
	p IS_A pressure;
	h IS_A specific_enthalpy;
	T IS_A temperature;
	s IS_A specific_entropy;
	iapws97: iapws97_Ts_ph(
		p, h : INPUT;
		T, s : OUTPUT
	);
END simple_state;

(* 
	Enhanced version of johnpye/thermalequilibrium.a4c. This model uses
	real steam properties from http://freesteam.sf.net/.

	NOTE: set the starting step to 0.1 and the minimum step to 0.01 s, and
	integrate from 0 to 3000 s.
*)
ADD NOTES IN thermalequilibrium2;
	'solver' name {QRSlv}
	'QRSlv' iterationlimit {50}
	'QRSlv' singtol {1e-10}
	'LSODE' minstep {0.01}
	'LSODE' firststep {0.1}
	'LSODE' maxstep {2000}
	'LSODE' duration {3000}
END NOTES;

MODEL thermalequilibrium2;
	S[1..2] IS_A simple_state;
	m[1..2] IS_A mass;
	h IS_A heat_transfer_coefficient;
	A IS_A area;

	p ALIASES S[1].p;
	S[2].p = S[1].p;

	Q IS_A energy_rate;
	Q = h*A*(S[1].T - S[2].T); (* rate of heat transfer from 1 to 2 *)
	m[1]*dhdt[1] = -Q;
	m[2]*dhdt[2] = +Q;
	
	dhdt[1..2] IS_A delta_specific_power;

	t IS_A time;
METHODS
METHOD on_load;
	FIX	h, A, m[1..2], S[1..2].h, p;
	A := 1 {m^2};
	h := 10 {W/m^2/K};

	p := 1 {bar};

	m[1] := 2 {kg};
	S[1].h := 200 {kJ/kg};
	m[2] := 10 {kg};
	S[2].h := 3500 {kJ/kg};

	FOR i IN [1..2] DO
		S[i].h.ode_id := i;
		dhdt[i].ode_id := i;
		S[i].h.ode_type := 1;
		dhdt[i].ode_type := 2;
	END FOR;

	Q.obs_id := 2;
	S[1].T.obs_id := 3;
	S[2].T.obs_id := 4;

	t.ode_type := -1;
	t := 0 {s};

END on_load;

METHOD listnotes;
	EXTERNAL listnotes(SELF);
END listnotes;

METHOD setup_solver;
	EXTERNAL setup_solver(SELF);
END setup_solver;

END thermalequilibrium2;
1	REQUIRE "ivpsystem.a4l";
2	REQUIRE "johnpye/thermo_types.a4c";
3
4	IMPORT "freesteam";
5	IMPORT "johnpye/extpy/extpy";
6	IMPORT "johnpye/listnotes";
7
8	MODEL simple_state;
9	p IS_A pressure;
10	h IS_A specific_enthalpy;
11	T IS_A temperature;
12	s IS_A specific_entropy;
13	iapws97: iapws97_Ts_ph(
14	p, h : INPUT;
15	T, s : OUTPUT
16	);
17	END simple_state;
18
19	(*
20	Enhanced version of johnpye/thermalequilibrium.a4c. This model uses
21	real steam properties from http://freesteam.sf.net/.
22
23	NOTE: set the starting step to 0.1 and the minimum step to 0.01 s, and
24	integrate from 0 to 3000 s.
25	*)
26	ADD NOTES IN thermalequilibrium2;
27	'solver' name {QRSlv}
28	'QRSlv' iterationlimit {50}
29	'QRSlv' singtol {1e-10}
30	'LSODE' minstep {0.01}
31	'LSODE' firststep {0.1}
32	'LSODE' maxstep {2000}
33	'LSODE' duration {3000}
34	END NOTES;
35
36	MODEL thermalequilibrium2;
37	S[1..2] IS_A simple_state;
38	m[1..2] IS_A mass;
39	h IS_A heat_transfer_coefficient;
40	A IS_A area;
41
42	p ALIASES S[1].p;
43	S[2].p = S[1].p;
44
45	Q IS_A energy_rate;
46	Q = hA(S[1].T - S[2].T); (* rate of heat transfer from 1 to 2 *)
47	m[1]*dhdt[1] = -Q;
48	m[2]*dhdt[2] = +Q;
49
50	dhdt[1..2] IS_A delta_specific_power;
51
52	t IS_A time;
53	METHODS
54	METHOD on_load;
55	FIX h, A, m[1..2], S[1..2].h, p;
56	A := 1 {m^2};
57	h := 10 {W/m^2/K};
58
59	p := 1 {bar};
60
61	m[1] := 2 {kg};
62	S[1].h := 200 {kJ/kg};
63	m[2] := 10 {kg};
64	S[2].h := 3500 {kJ/kg};
65
66	FOR i IN [1..2] DO
67	S[i].h.ode_id := i;
68	dhdt[i].ode_id := i;
69	S[i].h.ode_type := 1;
70	dhdt[i].ode_type := 2;
71	END FOR;
72
73	Q.obs_id := 2;
74	S[1].T.obs_id := 3;
75	S[2].T.obs_id := 4;
76
77	t.ode_type := -1;
78	t := 0 {s};
79
80	END on_load;
81
82	METHOD listnotes;
83	EXTERNAL listnotes(SELF);
84	END listnotes;
85
86	METHOD setup_solver;
87	EXTERNAL setup_solver(SELF);
88	END setup_solver;
89
90	END thermalequilibrium2;