| 1 |
REQUIRE "johnpye/thermo_types.a4c"; |
| 2 |
|
| 3 |
MODEL ideal_steam REFINES thermo_state; |
| 4 |
|
| 5 |
delta IS_A positive_variable; |
| 6 |
tau IS_A positive_variable; |
| 7 |
|
| 8 |
(*-------------- CONSTANTS ---------------*) |
| 9 |
rhoc IS_A mass_density_constant; |
| 10 |
Tc IS_A temperature_constant; |
| 11 |
|
| 12 |
rhoc "density of water at the critical point" |
| 13 |
:== 322 {kg/m^3}; |
| 14 |
|
| 15 |
Tc "temperature of water at the critical point" |
| 16 |
:== 647.096 {K}; |
| 17 |
|
| 18 |
R IS_A specific_gas_constant; |
| 19 |
R "specific gas constant for water" |
| 20 |
:== 0.46151805 {kJ/kg/K}; |
| 21 |
|
| 22 |
z_01: tau = Tc / T; |
| 23 |
z_02: delta = rho / rhoc; |
| 24 |
|
| 25 |
|
| 26 |
range_0 IS_A set OF integer_constant; |
| 27 |
range_0 :== [1..8]; |
| 28 |
|
| 29 |
range_01 IS_A set OF integer_constant; |
| 30 |
range_01 :== [4..8]; |
| 31 |
|
| 32 |
range_r1 IS_A set OF integer_constant; |
| 33 |
range_r1 :== [1..7]; |
| 34 |
|
| 35 |
range_r2 IS_A set OF integer_constant; |
| 36 |
range_r2 :== [8..51]; |
| 37 |
|
| 38 |
range_r3 IS_A set OF integer_constant; |
| 39 |
range_r3 :== [52..54]; |
| 40 |
|
| 41 |
range_r4 IS_A set OF integer_constant; |
| 42 |
range_r4 :== [55..56]; |
| 43 |
|
| 44 |
n0[range_0] IS_A real_constant; |
| 45 |
n0[1] :== -8.32044648201; |
| 46 |
|
| 47 |
n0[2] :== 6.6832105268; |
| 48 |
n0[3] :== 3.00632; |
| 49 |
n0[4] :== 0.012436; |
| 50 |
|
| 51 |
n0[5] :== 0.97315; |
| 52 |
n0[6] :== 1.27950; |
| 53 |
n0[7] :== 0.96956; |
| 54 |
n0[8] :== 0.24873; |
| 55 |
|
| 56 |
gamma0[range_01] IS_A real_constant; |
| 57 |
gamma0[4] :== 1.28728967; |
| 58 |
gamma0[5] :== 3.53734222; |
| 59 |
gamma0[6] :== 7.74073708; |
| 60 |
gamma0[7] :== 9.24437796; |
| 61 |
gamma0[8] :== 27.5075105; |
| 62 |
|
| 63 |
(*------------ IDEAL PARTS ------------*) |
| 64 |
|
| 65 |
phi0 IS_A factor; |
| 66 |
z_phi0_expr: phi0 = |
| 67 |
SUM[ n0[i]*ln(1-exp(-tau*gamma0[i])) | i IN [range_01] ] |
| 68 |
+ ln(delta) + n0[1] + n0[2]*tau + n0[3]*ln(tau); |
| 69 |
|
| 70 |
phi0delta IS_A factor; |
| 71 |
z_phi0delta_expr: phi0delta = 1.0/delta; |
| 72 |
|
| 73 |
phi0deltadelta IS_A factor; |
| 74 |
z_phi0deltadelta_expr: phi0deltadelta = |
| 75 |
-1.0/(delta*delta); |
| 76 |
|
| 77 |
|
| 78 |
phi0tau IS_A factor; |
| 79 |
z_phi0tau_expr: phi0tau = |
| 80 |
n0[2] + n0[3]/tau |
| 81 |
+ SUM[ n0[i]*gamma0[i]*(1/(1-exp(-tau*gamma0[i])) - 1) | i IN [range_01] ]; |
| 82 |
|
| 83 |
phi0deltatau IS_A real_constant; |
| 84 |
phi0deltatau :== 0.0; |
| 85 |
|
| 86 |
phi0tautau IS_A factor; |
| 87 |
z_phi0tautau_expr: phi0tautau |
| 88 |
= -n0[3] / tau^2 |
| 89 |
- SUM [ n0[i] * gamma0[i]^2 * exp(-gamma0[i] * tau) / ( 1 - exp(-gamma0[i] * tau) )^2 | i IN range_01 ]; |
| 90 |
|
| 91 |
|
| 92 |
(*--------- THERMO PROPERTY RELATIONS ----------- *) |
| 93 |
|
| 94 |
z_pressure: p = rho * R * T; |
| 95 |
|
| 96 |
z_internal_energy: u = R * T * tau * (phi0tau); |
| 97 |
|
| 98 |
z_enthalpy: h = R * T * (1 + tau*(phi0tau)); |
| 99 |
|
| 100 |
z_entropy: s = R * (tau*(phi0tau) - phi0); |
| 101 |
|
| 102 |
z_c_isochoric: cv = - R * tau^2 * (phi0tautau); |
| 103 |
|
| 104 |
z_c_isobaric: cp = - R * tau^2 * (phi0tautau); |
| 105 |
|
| 106 |
(* z_spd_sound: w^2 |
| 107 |
= R * T * (1 - 1/(tau^2 * phi0tautau)); *) |
| 108 |
|
| 109 |
METHODS |
| 110 |
METHOD default_self; |
| 111 |
RUN ClearAll; |
| 112 |
RUN specify; |
| 113 |
RUN values; |
| 114 |
END default_self; |
| 115 |
|
| 116 |
METHOD specify; |
| 117 |
FIX T; |
| 118 |
FIX rho; |
| 119 |
END specify; |
| 120 |
|
| 121 |
METHOD values; |
| 122 |
(* these are the test values from page 14 of the IAPWS-95 release *) |
| 123 |
T := 500 {K}; |
| 124 |
rho := 838.025 {kg/m^3}; |
| 125 |
END values; |
| 126 |
|
| 127 |
END ideal_steam; |
Parent Directory
| 
Revision Log