## Description

Aspen contains a collection of thermodynamic functions that were obtained from PAM II Derived Parameters (reference given below). There are a number of constants that are shared among the formulas.

## Constants

$$A = 5.0065 \\ B = 19.83923 \\ C_P = 1005.7 \\ R_D = 287.0 \\ E_3 = 6.1078 \\ T_3 = 273.15 \\ \epsilon = 0.622 \\$$

## Lookup table of saturation vapor pressure

For every 1/2 degree from 210 K to 310 K:

$$ETBL_{MIN} = 210.0 \\ ETBL_{MAX} = 310.0 \\ ETBL_{STEP} = 0.5 \\$$
$$ETBL[ ] = \\ \text { /* 210.0 */ } 0.01296, 0.01383, 0.01475, 0.01573, \\ \text { /* 212.0 */ } 0.01677, 0.01787, 0.01904, 0.02027, \\ \text { /* 214.0 */ } 0.02158, 0.02296, 0.02443, 0.02598, \\ \text { /* 216.0 */ } 0.02763, 0.02936, 0.03120, 0.03314, \\ \text { /* 218.0 */ } 0.03520, 0.03736, 0.03965, 0.04207, \\ \text { /* 220.0 */ } 0.04462, 0.04731, 0.05015, 0.05315, \\ \text { /* 222.0 */ } 0.05631, 0.05963, 0.06314, 0.06684, \\ \text { /* 224.0 */ } 0.07073, 0.07483, 0.07914, 0.08368, \\ \text { /* 226.0 */ } 0.08845, 0.09347, 0.09876, 0.10431, \\ \text { /* 228.0 */ } 0.11014, 0.11627, 0.12271, 0.12947, \\ \text { /* 230.0 */ } 0.13657, 0.14403, 0.15185, 0.16006, \\ \text { /* 232.0 */ } 0.16866, 0.17769, 0.18715, 0.19707, \\ \text { /* 234.0 */ } 0.20746, 0.21835, 0.22975, 0.24170, \\ \text { /* 236.0 */ } 0.25420, 0.26729, 0.28098, 0.29531, \\ \text { /* 238.0 */ } 0.31030, 0.32597, 0.34235, 0.35948, \\ \text { /* 240.0 */ } 0.37738, 0.39608, 0.41562, 0.43603, \\ \text { /* 242.0 */ } 0.45733, 0.47957, 0.50279, 0.52701, \\ \text { /* 244.0 */ } 0.55229, 0.57865, 0.60615, 0.63481, \\ \text { /* 246.0 */ } 0.66470, 0.69584, 0.72830, 0.76211, \\ \text { /* 248.0 */ } 0.79733, 0.83402, 0.87221, 0.91197, \\ \text { /* 250.0 */ } 0.95335, 0.99642, 1.04122, 1.08783, \\ \text { /* 252.0 */ } 1.13631, 1.18671, 1.23912, 1.29360, \\ \text { /* 254.0 */ } 1.35021, 1.40904, 1.47016, 1.53364, \\ \text { /* 256.0 */ } 1.59957, 1.66803, 1.73910, 1.81288, \\ \text { /* 258.0 */ } 1.88944, 1.96888, 2.05130, 2.13680, \\ \text { /* 260.0 */ } 2.22546, 2.31740, 2.41272, 2.51152, \\ \text { /* 262.0 */ } 2.61393, 2.72005, 2.82999, 2.94388, \\ \text { /* 264.0 */ } 3.06184, 3.18400, 3.31049, 3.44144, \\ \text { /* 266.0 */ } 3.57697, 3.71725, 3.86240, 4.01257, \\ \text { /* 268.0 */ } 4.16791, 4.32858, 4.49474, 4.66654, \\ \text { /* 270.0 */ } 4.84415, 5.02773, 5.21748, 5.41355, \\ \text { /* 272.0 */ } 5.61613, 5.82541, 6.04158, 6.26483, \\ \text { /* 274.0 */ } 6.49536, 6.73337, 6.97908, 7.23269, \\ \text { /* 276.0 */ } 7.49443, 7.76451, 8.04316, 8.33062, \\ \text { /* 278.0 */ } 8.62713, 8.93292, 9.24825, 9.57337, \\ \text { /* 280.0 */ } 9.90853, 10.25401, 10.61007, 10.97699, \\ \text { /* 282.0 */ } 11.35505, 11.74454, 12.14575, 12.55898, \\ \text { /* 284.0 */ } 12.98454, 13.42274, 13.87390, 14.33834, \\ \text { /* 286.0 */ } 14.81640, 15.30841, 15.81471, 16.33567, \\ \text { /* 288.0 */ } 16.87163, 17.42296, 17.99004, 18.57325, \\ \text { /* 290.0 */ } 19.17296, 19.78958, 20.42351, 21.07515, \\ \text { /* 292.0 */ } 21.74492, 22.43326, 23.14058, 23.86733, \\ \text { /* 294.0 */ } 24.61396, 25.38092, 26.16869, 26.97773, \\ \text { /* 296.0 */ } 27.80852, 28.66155, 29.53732, 30.43635, \\ \text { /* 298.0 */ } 31.35914, 32.30622, 33.27813, 34.27540, \\ \text { /* 300.0 */ } 35.29859, 36.34827, 37.42500, 38.52936, \\ \text { /* 302.0 */ } 39.66194, 40.82335, 42.01419, 43.23508, \\ \text { /* 304.0 */ } 44.48666, 45.76955, 47.08442, 48.43193, \\ \text { /* 306.0 */ } 49.81273, 51.22752, 52.67699, 54.16184, \\ \text { /* 308.0 */ } 55.68278, 57.24053, 58.83584, 60.46945, \\ \text { /* 310.0 */ } 62.14212 \\$$

## Source

PAM II Derived Parameters

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