com.synerset.hvacengine.fluids.SharedEquations Maven / Gradle / Ivy
package com.synerset.hvacengine.fluids;
import com.synerset.hvacengine.common.Validators;
import com.synerset.unitility.unitsystem.common.Distance;
import com.synerset.unitility.unitsystem.dimensionless.PrandtlNumber;
import com.synerset.unitility.unitsystem.thermodynamic.*;
public final class SharedEquations {
private SharedEquations() {
}
/**
* Returns atmospheric pressure based on height above the sea level, Pa
* REFERENCE SOURCE: [1] [Pat,Pa] (3) [6.2]
* EQUATION LIMITS: {-5000m,+1100m}
*
* @param altitude altitude over sea level (can be negative), m
* @return atmospheric pressure at provided altitude, Pa
*/
public static double atmAltitudePressure(double altitude) {
return 101.325 * Math.pow((1 - 2.25577 * Math.pow(10, -5) * altitude), 5.2559) * 1000;
}
public static Pressure atmAltitudePressure(Distance altitude) {
Validators.requireNotNull(altitude);
double pressVal = atmAltitudePressure(altitude.getInMeters());
return Pressure.ofPascal(pressVal);
}
/**
* Returns moist air temperature based on height above the sea level, oC
* REFERENCE SOURCE: [1] [Pat,Pa] (4) [6.2]
* EQUATION LIMITS: {-5000m,+1100m}
*
* @param tempAtSeaLevel temperature at altitude of 0.0m, oC
* @param altitude altitude over sea level (can be negative), m
* @return temperature at provided altitude, oC
*/
public static double altitudeTemperature(double tempAtSeaLevel, double altitude) {
return tempAtSeaLevel - 0.0065 * altitude;
}
public static Temperature altitudeTemperature(Temperature tempAtSeaLevel, Distance altitude) {
Validators.requireNotNull(tempAtSeaLevel);
Validators.requireNotNull(altitude);
double tempVal = altitudeTemperature(tempAtSeaLevel.getInCelsius(), altitude.getInMeters());
return Temperature.ofCelsius(tempVal);
}
/**
* Returns thermal diffusivity, m2/s
* REFERENCE SOURCE: [8] [am,m2/s] (35) [5]
*
* @param rho air density, kg/m3
* @param k air thermal conductivity, W/(m*K)
* @param cp air specific heat, kJ/kgK
* @return air thermal diffusivity, m2/s
*/
public static double thermalDiffusivity(double rho, double k, double cp) {
return k / (rho * cp * 1000d);
}
public static ThermalDiffusivity thermalDiffusivity(Density density, ThermalConductivity thermalConductivity, SpecificHeat specificHeat) {
Validators.requireNotNull(density);
Validators.requireNotNull(thermalConductivity);
Validators.requireNotNull(specificHeat);
double thermalDiffVal = thermalDiffusivity(density.getInKilogramsPerCubicMeters(),
thermalConductivity.getInWattsPerMeterKelvin(),
specificHeat.getInKiloJoulesPerKiloGramKelvin());
return ThermalDiffusivity.ofSquareMeterPerSecond(thermalDiffVal);
}
/**
* Returns air Prandtl number, -
* Valid for DA, WV, MA if all arguments are provided for type of fluid.
*
* @param dynVis air dynamic viscosity,kg/(m*s)
* @param k air thermal conductivity, W/mK
* @param cp air specific heat, kJ/kgK
* @return Prandtl number, -
*/
public static double prandtlNumber(double dynVis, double k, double cp) {
return dynVis * cp * 1000d / k;
}
public static PrandtlNumber prandtlNumber(DynamicViscosity dynamicViscosity, ThermalConductivity thermalConductivity, SpecificHeat specificHeat) {
Validators.requireNotNull(dynamicViscosity);
Validators.requireNotNull(thermalConductivity);
Validators.requireNotNull(specificHeat);
double prandtlVal = prandtlNumber(dynamicViscosity.getInPascalsSecond(),
thermalConductivity.getInWattsPerMeterKelvin(),
specificHeat.getInKiloJoulesPerKiloGramKelvin());
return PrandtlNumber.of(prandtlVal);
}
}