156 lines
4.5 KiB
C++
156 lines
4.5 KiB
C++
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/// \cond
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// C headers
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// C++ headers
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#include <cmath>
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// 3rd party headers
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/// \endcond
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// qtrocket headers
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#include "sim/USStandardAtmosphere.h"
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#include "utils/math/Constants.h"
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#include "utils/math/UtilityMathFunctions.h"
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using namespace utils::math;
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namespace sim
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{
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// Populate static data
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utils::Bin initTemps()
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{
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utils::Bin map;
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map.insert(std::make_pair(0.0, 288.15));
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map.insert(std::make_pair(11000.0, 216.65));
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map.insert(std::make_pair(20000.0, 216.65));
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map.insert(std::make_pair(32000.0, 228.65));
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map.insert(std::make_pair(47000.0, 270.65));
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map.insert(std::make_pair(51000.0, 270.65));
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map.insert(std::make_pair(71000.0, 214.65));
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return map;
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}
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utils::Bin initLapseRates()
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{
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utils::Bin map;
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map.insert(std::make_pair(0.0, 0.0065));
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map.insert(std::make_pair(11000.0, 0.0));
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map.insert(std::make_pair(20000.0, -0.001));
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map.insert(std::make_pair(32000.0, -0.0028));
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map.insert(std::make_pair(47000.0, 0.0));
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map.insert(std::make_pair(51000.0, 0.0028));
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map.insert(std::make_pair(71000.0, 0.002));
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return map;
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}
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utils::Bin initDensities()
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{
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utils::Bin map;
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map.insert(std::make_pair(0.0, 1.225));
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map.insert(std::make_pair(11000.0, 0.36391));
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map.insert(std::make_pair(20000.0, 0.08803));
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map.insert(std::make_pair(32000.0, 0.01322));
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map.insert(std::make_pair(47000.0, 0.00143));
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map.insert(std::make_pair(51000.0, 0.00086));
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map.insert(std::make_pair(71000.0, 0.000064));
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return map;
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}
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utils::Bin initPressures()
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{
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utils::Bin map;
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map.insert(std::make_pair(0.0, 101325));
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map.insert(std::make_pair(11000.0, 22632.1));
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map.insert(std::make_pair(20000.0, 5474.89));
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map.insert(std::make_pair(32000.0, 868.02));
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map.insert(std::make_pair(47000.0, 110.91));
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map.insert(std::make_pair(51000.0, 66.94));
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map.insert(std::make_pair(71000.0, 3.96));
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return map;
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}
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utils::Bin USStandardAtmosphere::temperatureLapseRate(initLapseRates());
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utils::Bin USStandardAtmosphere::standardTemperature(initTemps());
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utils::Bin USStandardAtmosphere::standardDensity(initDensities());
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utils::Bin USStandardAtmosphere::standardPressure(initPressures());
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USStandardAtmosphere::USStandardAtmosphere()
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{
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}
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USStandardAtmosphere::~USStandardAtmosphere()
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{
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}
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double USStandardAtmosphere::getDensity(double altitude)
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{
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if(utils::math::floatingPointEqual(temperatureLapseRate[altitude], 0.0))
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{
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return standardDensity[altitude] * std::exp(
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(-Constants::g0 * Constants::airMolarMass * (altitude - standardDensity.getBinBase(altitude)))
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/ (Constants::Rstar * standardTemperature[altitude]));
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}
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else
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{
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double base = (standardTemperature[altitude] - temperatureLapseRate[altitude] *
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(altitude - standardDensity.getBinBase(altitude))) / standardTemperature[altitude];
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double exponent = (Constants::g0 * Constants::airMolarMass) /
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(Constants::Rstar * temperatureLapseRate[altitude]) - 1.0;
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return standardDensity[altitude] * std::pow(base, exponent);
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}
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}
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double USStandardAtmosphere::getTemperature(double altitude)
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{
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double baseTemp = standardTemperature[altitude];
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double baseAltitude = standardTemperature.getBinBase(altitude);
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return baseTemp - (altitude - baseAltitude) * temperatureLapseRate[altitude];
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}
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double USStandardAtmosphere::getPressure(double altitude)
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{
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if(utils::math::floatingPointEqual(temperatureLapseRate[altitude], 0.0))
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{
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return standardPressure[altitude] * std::exp(
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(-Constants::g0 * Constants::airMolarMass * (altitude - standardPressure.getBinBase(altitude)))
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/ (Constants::Rstar * standardTemperature[altitude]));
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}
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else
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{
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double base = (standardTemperature[altitude] - temperatureLapseRate[altitude] *
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(altitude - standardPressure.getBinBase(altitude))) / standardTemperature[altitude];
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double exponent = (Constants::g0 * Constants::airMolarMass) /
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(Constants::Rstar * temperatureLapseRate[altitude]);
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return standardPressure[altitude] * std::pow(base, exponent);
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}
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}
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double USStandardAtmosphere::getSpeedOfSound(double altitude)
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{
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return std::sqrt( (Constants::gamma * Constants::Rstar * getTemperature(altitude))
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/
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Constants::airMolarMass);
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}
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double USStandardAtmosphere::getDynamicViscosity(double altitude)
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{
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double temperature = getTemperature(altitude);
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return (Constants::beta * std::pow(temperature, 1.5)) / ( temperature + Constants::S);
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}
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} // namespace sim
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