1 /* Copyright 2022-2025 Thales Alenia Space
2 * Licensed to CS Communication & Systèmes (CS) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * CS licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.orekit.models.earth.weather.water;
18
19 import org.hipparchus.CalculusFieldElement;
20 import org.hipparchus.analysis.interpolation.SplineInterpolator;
21 import org.hipparchus.analysis.polynomials.PolynomialSplineFunction;
22 import org.hipparchus.util.FastMath;
23
24 /** Steam table from US National Bureau of Standards (NBS) and National Research Council (NRC) of Canada.
25 * <p>
26 * The table is an extract from table 1 in <a href="https://www.thermopedia.com/content/1150/">Thermopedia</a>,
27 * using only the pressure column and truncated to 99°C (the original table goes up to 373.976°C). According to
28 * <a href="https://www.thermopedia.com/access/">the access page</a>, this data is available for free.
29 * </p>
30 * @see <a href="https://dx.doi.org/10.1615/AtoZ.s.steam_tables">Thermopedia Steam Tables</a>
31 *
32 * @author Luc Maisonobe
33 * @since 12.1
34 */
35 public class NbsNrcSteamTable implements WaterVaporPressureProvider {
36
37 /** Celsius temperature offset. */
38 private static final double CELSIUS = 273.15;
39
40 /** Minimum temperature of the model, at the triple point of water, i.e. 273.16K (which is 0.01°C). */
41 private static final double MIN_T = CELSIUS + 0.01;
42
43 /** Saturation pressure model. */
44 private static final PolynomialSplineFunction MODEL;
45
46 static {
47
48 // saturation pressure in SI units (Pa)
49 final double[] pressure = {
50 00611.73, 657.16, 706.05, 758.13, 813.59, 872.60, 935.37, 1002.09, 1072.97, 1148.25,
51 01228.10, 1312.90, 1402.70, 1497.90, 1598.80, 1705.60, 1818.50, 1938.00, 2064.40, 2197.90,
52 02338.80, 2487.70, 2644.70, 2810.40, 2985.00, 3169.10, 3362.90, 3567.00, 3781.80, 4007.80,
53 04245.50, 4495.30, 4757.80, 5033.50, 5322.90, 5626.70, 5945.40, 6279.50, 6629.80, 6996.90,
54 07381.40, 7784.00, 8205.40, 8646.40, 9107.60, 9589.80, 10093.80, 10620.50, 11170.60, 11744.90,
55 12344.00, 12970.00, 13623.00, 14303.00, 15012.00, 15752.00, 16522.00, 17324.00, 18159.00, 19028.00,
56 19932.00, 20873.00, 21851.00, 22868.00, 23925.00, 25022.00, 26163.00, 27347.00, 28576.00, 29852.00,
57 31176.00, 32549.00, 33972.00, 35448.00, 36978.00, 38563.00, 40205.00, 41905.00, 43665.00, 45487.00,
58 47373.00, 49324.00, 51342.00, 53428.00, 55585.00, 57815.00, 60119.00, 62499.00, 64958.00, 67496.00,
59 70117.00, 72823.00, 75614.00, 78495.00, 81465.00, 84529.00, 87688.00, 90945.00, 94301.00, 97759.00
60 };
61
62 // the table first entry is at 0.01°C, not 0.00°C, but remaining entries are 1°C, 2°C, … 99°C
63 final double[] temperature = new double[pressure.length];
64 for (int i = 0; i < temperature.length; ++i) {
65 temperature[i] = (i == 0) ? MIN_T : (CELSIUS + i);
66 }
67
68 MODEL = new SplineInterpolator().interpolate(temperature, pressure);
69
70 }
71
72 /** {@inheritDoc} */
73 @Override
74 public double waterVaporPressure(final double p, final double t, final double rh) {
75 return MODEL.value(FastMath.max(t, MIN_T)) * rh;
76 }
77
78 /** {@inheritDoc} */
79 @Override
80 public <T extends CalculusFieldElement<T>> T waterVaporPressure(final T p, final T t, final T rh) {
81 return MODEL.value(FastMath.max(t, MIN_T)).multiply(rh);
82 }
83
84 }