models/steam/iapwssat.a4c

REQUIRE "steam/iapwssatprops.a4c";

MODEL iapwssat REFINES iapwssatprops;
	x IS_A fraction; (* ensures we stay in the required region *)
	h IS_A specific_enthalpy;
	u IS_A specific_energy;
	v IS_A specific_volume;

	h_expr: h = (h_g - h_f) * x + h_f;
	u_expr: u = (u_g - u_f) * x + u_f;
	v_expr: v * ( rho_f * rho_g ) = (rho_g + (rho_f - rho_g)*x );
METHODS
METHOD default_self;
	x := 0.5;
	h := 2800 {kJ/kg};
	u := 2300 {kJ/kg};
	v := 100 {m^3/kg};
	v.nominal := 0.01 {m^3/kg};
	RUN iapwssatprops::default_self;
END default_self;
METHOD bound_self;
	T.lower_bound := 273 {K};
END bound_self;
METHOD specify;
	FIX x;
	RUN iapwssatprops::specify;
END specify;
METHOD values;
	x := 0.5;
	RUN iapwssatprops::values;
END values;
METHOD on_load;
	RUN default_self;
	RUN reset; RUN values;
	RUN bound_self;
END on_load;
END iapwssat;

(*
	not sure what to do with this test case. We are trying to show that
	illegal values of quality 'x' will fix themselves up somehow.
*)
MODEL testiapwssat1 REFINES iapwssat;
METHODS
METHOD values;
	RUN iapwssatprops::values;
	x := 1.01;
	x.upper_bound := 1.0;
	x.lower_bound := 0.0;
END values;
METHOD self_test;
	ASSERT x <= x.upper_bound;
	ASSERT x >= x.lower_bound;
END self_test;
END testiapwssat1;

(*
	test our ability to converge steam properties using the above when
	(u,v) are fixed.
*)
MODEL testiapwssatuv REFINES iapwssat;
METHODS
METHOD specify;
	FIX u,v;
END specify;
METHOD values;
	v := 1.0 / (500 {kg/m^3});
	u := 780 {kJ/kg};
END values;
METHOD self_test;
	ASSERT abs(p - 10.540441 {bar}) < 0.000002 {bar};
	ASSERT abs(T - (273.15{K} + 182.177917{K})) < 0.000001 {K};
	ASSERT abs(x - 0.004734) < 0.000001;
END self_test;
METHOD values2;
	v := 1.0 / (450 {kg/m^3});
	u := 780 {kJ/kg};
END values2;
METHOD self_test2;
	ASSERT abs(p - 10.426431 {bar}) < 0.000002 {bar};
	ASSERT abs(T - (273.15{K} + 181.700586{K})) < 0.000001 {K};
	ASSERT abs(x - 0.005885) < 0.000001;
END self_test2;

END testiapwssatuv;
1	REQUIRE "steam/iapwssatprops.a4c";
2
3	MODEL iapwssat REFINES iapwssatprops;
4	x IS_A fraction; (* ensures we stay in the required region *)
5	h IS_A specific_enthalpy;
6	u IS_A specific_energy;
7	v IS_A specific_volume;
8
9	h_expr: h = (h_g - h_f) * x + h_f;
10	u_expr: u = (u_g - u_f) * x + u_f;
11	v_expr: v * ( rho_f * rho_g ) = (rho_g + (rho_f - rho_g)*x );
12	METHODS
13	METHOD default_self;
14	x := 0.5;
15	h := 2800 {kJ/kg};
16	u := 2300 {kJ/kg};
17	v := 100 {m^3/kg};
18	v.nominal := 0.01 {m^3/kg};
19	RUN iapwssatprops::default_self;
20	END default_self;
21	METHOD bound_self;
22	T.lower_bound := 273 {K};
23	END bound_self;
24	METHOD specify;
25	FIX x;
26	RUN iapwssatprops::specify;
27	END specify;
28	METHOD values;
29	x := 0.5;
30	RUN iapwssatprops::values;
31	END values;
32	METHOD on_load;
33	RUN default_self;
34	RUN reset; RUN values;
35	RUN bound_self;
36	END on_load;
37	END iapwssat;
38
39	(*
40	not sure what to do with this test case. We are trying to show that
41	illegal values of quality 'x' will fix themselves up somehow.
42	*)
43	MODEL testiapwssat1 REFINES iapwssat;
44	METHODS
45	METHOD values;
46	RUN iapwssatprops::values;
47	x := 1.01;
48	x.upper_bound := 1.0;
49	x.lower_bound := 0.0;
50	END values;
51	METHOD self_test;
52	ASSERT x <= x.upper_bound;
53	ASSERT x >= x.lower_bound;
54	END self_test;
55	END testiapwssat1;
56
57	(*
58	test our ability to converge steam properties using the above when
59	(u,v) are fixed.
60	*)
61	MODEL testiapwssatuv REFINES iapwssat;
62	METHODS
63	METHOD specify;
64	FIX u,v;
65	END specify;
66	METHOD values;
67	v := 1.0 / (500 {kg/m^3});
68	u := 780 {kJ/kg};
69	END values;
70	METHOD self_test;
71	ASSERT abs(p - 10.540441 {bar}) < 0.000002 {bar};
72	ASSERT abs(T - (273.15{K} + 182.177917{K})) < 0.000001 {K};
73	ASSERT abs(x - 0.004734) < 0.000001;
74	END self_test;
75	METHOD values2;
76	v := 1.0 / (450 {kg/m^3});
77	u := 780 {kJ/kg};
78	END values2;
79	METHOD self_test2;
80	ASSERT abs(p - 10.426431 {bar}) < 0.000002 {bar};
81	ASSERT abs(T - (273.15{K} + 181.700586{K})) < 0.000001 {K};
82	ASSERT abs(x - 0.005885) < 0.000001;
83	END self_test2;
84
85	END testiapwssatuv;