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/* This file is part of the OpenLB library
*
* Copyright (C) 2017 Max Gaedtke, Albert Mink
* E-mail contact: info@openlb.net
* The most recent release of OpenLB can be downloaded at
* <http://www.openlb.net/>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this program; if not, write to the Free
* Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
/** \file
* Unit conversion handling -- header file.
*/
#ifndef THERMALUNITCONVERTER_H
#define THERMALUNITCONVERTER_H
#include <math.h>
#include "io/ostreamManager.h"
#include "core/util.h"
#include "io/xmlReader.h"
#include "core/unitConverter.h"
/// All OpenLB code is contained in this namespace.
namespace olb {
/** Conversion between physical and lattice units, as well as discretization specialized for thermal applications with boussinesq approximation.
* Be aware of the nomenclature:
* We distingish between physical (dimensioned) and lattice (dimensionless) values.
* A specific conversion factor maps the two different scopes,
* e.g. __physLength = conversionLength * latticeLength__
*
* For pressure and temperature we first shift the physical values by a characteristic value to asure a lattice pressure and between 0 and 1, e.g. __physPressure - charPhysPressure = conversionPressure * latticePressure__. For the temperature we set lattice values between 0.5 and 1.5 by __latticeTemperature = (physTemperature - charPhysLowTemperature) / conversionTemperature + 0.5 with conversionTemperature = charPhysHighTemperature - charPhysLowTemperature = charPhysTemperatureDifference
*
* TODO: Extend documentation for ThermalUnitConverter
*/
template <typename T, typename DESCRIPTOR, typename ThermalLattice>
class ThermalUnitConverter : public UnitConverter<T, DESCRIPTOR> {
public:
/** Documentation of constructor:
* TODO: Extend constructur documentation
*/
constexpr ThermalUnitConverter(
T physDeltaX,
T physDeltaT,
T charPhysLength,
T charPhysVelocity,
T physViscosity,
T physDensity,
T physThermalConductivity,
T physSpecificHeatCapacity,
T physThermalExpansionCoefficient,
T charPhysLowTemperature,
T charPhysHighTemperature,
T charPhysPressure = 0 )
: UnitConverter<T, DESCRIPTOR>(
physDeltaX, physDeltaT, charPhysLength, charPhysVelocity,
physViscosity, physDensity, charPhysPressure),
_conversionTemperature(charPhysHighTemperature - charPhysLowTemperature),
_conversionThermalDiffusivity(this->_conversionViscosity),
_conversionSpecificHeatCapacity(this->_conversionVelocity * this->_conversionVelocity / _conversionTemperature),
_conversionThermalConductivity(this->_conversionForce / this->_conversionTime / _conversionTemperature),
_conversionHeatFlux(this->_conversionMass / pow(this->_conversionTime, 3)),
_charPhysLowTemperature(charPhysLowTemperature),
_charPhysHighTemperature(charPhysHighTemperature),
_charPhysTemperatureDifference(charPhysHighTemperature - charPhysLowTemperature),
_physThermalExpansionCoefficient(physThermalExpansionCoefficient),
_physThermalDiffusivity(physThermalConductivity / (physDensity * physSpecificHeatCapacity)),
_physSpecificHeatCapacity(physSpecificHeatCapacity),
_physThermalConductivity(physThermalConductivity),
_latticeThermalRelaxationTime( (_physThermalDiffusivity / _conversionThermalDiffusivity * descriptors::invCs2<T,ThermalLattice>()) + 0.5 ),
clout(std::cout,"ThermalUnitConv")
{
};
/// return thermal relaxation time in lattice units
constexpr T getLatticeThermalRelaxationTime( ) const
{
return _latticeThermalRelaxationTime;
};
/// return thermal relaxation frequency in lattice units
constexpr T getLatticeThermalRelaxationFrequency( ) const
{
return 1.0 / _latticeThermalRelaxationTime;
};
/// return characteristic low temperature in physical units
constexpr T getCharPhysLowTemperature( ) const
{
return _charPhysLowTemperature;
};
/// return characteristic high temperature in physical units
constexpr T getCharPhysHighTemperature( ) const
{
return _charPhysHighTemperature;
};
/// return characteristic temperature difference in physical units
constexpr T getCharPhysTemperatureDifference( ) const
{
return _charPhysTemperatureDifference;
};
/// return thermal expansion coefficient in physical units
constexpr T getPhysThermalExpansionCoefficient( ) const
{
return _physThermalExpansionCoefficient;
};
/// return thermal diffusivity in physical units
constexpr T getPhysThermalDiffusivity( ) const
{
return _physThermalDiffusivity;
};
/// return specific heat capacity in physical units
constexpr T getPhysSpecificHeatCapacity( ) const
{
return _physSpecificHeatCapacity;
};
/// return thermal conductivity in physical units
constexpr T getThermalConductivity( ) const
{
return _physThermalConductivity;
};
/// conversion from lattice to physical temperature
constexpr T getPhysTemperature( T latticeTemperature ) const
{
return _conversionTemperature * (latticeTemperature - 0.5) + _charPhysLowTemperature;
};
/// conversion from physical to lattice temperature
constexpr T getLatticeTemperature( T physTemperature ) const
{
return (physTemperature - _charPhysLowTemperature) / _conversionTemperature + 0.5;
};
/// access (read-only) to private member variable
constexpr T getConversionFactorTemperature() const
{
return _conversionTemperature;
};
/// conversion from lattice to physical thermal diffusivity
constexpr T getPhysThermalDiffusivity( T latticeThermalDiffusivity ) const
{
return _conversionThermalDiffusivity * latticeThermalDiffusivity;
};
/// conversion from physical to lattice thermal diffusivity
constexpr T getLatticeThermalDiffusivity( T physThermalDiffusivity ) const
{
return physThermalDiffusivity / _conversionThermalDiffusivity;
};
/// access (read-only) to private member variable
constexpr T getConversionFactorThermalDiffusivity() const
{
return _conversionThermalDiffusivity;
};
/// conversion from lattice to physical specific heat capacity
constexpr T getPhysSpecificHeatCapacity( T latticeSpecificHeatCapacity ) const
{
return _conversionSpecificHeatCapacity * latticeSpecificHeatCapacity;
};
/// conversion from physical to lattice specific heat capacity
constexpr T getLatticeSpecificHeatCapacity( T physSpecificHeatCapacity ) const
{
return physSpecificHeatCapacity / _conversionSpecificHeatCapacity;
};
/// access (read-only) to private member variable
constexpr T getConversionFactorSpecificHeatCapacity() const
{
return _conversionSpecificHeatCapacity;
};
/// conversion from lattice to physical thermal conductivity
constexpr T getPhysThermalConductivity( T latticeThermalConductivity ) const
{
return _conversionThermalConductivity * latticeThermalConductivity;
};
/// conversion from physical to lattice thermal conductivity
constexpr T getLatticeThermalConductivity( T physThermalConductivity ) const
{
return physThermalConductivity / _conversionThermalConductivity;
};
/// access (read-only) to private member variable
constexpr T getConversionFactorThermalConductivity() const
{
return _conversionThermalConductivity;
};
/// conversion from lattice to physical heat flux
constexpr T getPhysHeatFlux( T latticeHeatFlux ) const
{
return _conversionHeatFlux * latticeHeatFlux;
};
/// conversion from physical to lattice heat flux
constexpr T getLatticeHeatFlux( T physHeatFlux ) const
{
return physHeatFlux / _conversionHeatFlux;
};
/// access (read-only) to private member variable
constexpr T getConversionFactorHeatFlux() const
{
return _conversionHeatFlux;
};
constexpr T getPrandtlNumber() const{
return this->_physViscosity/_physThermalDiffusivity;
};
constexpr T getRayleighNumber() const{
return 9.81 * _physThermalExpansionCoefficient/this->_physViscosity/_physThermalDiffusivity * (_charPhysHighTemperature - _charPhysLowTemperature) * pow(this->_charPhysLength,3);
};
/// nice terminal output for conversion factors, characteristical and physical data
virtual void print() const;
void write(std::string const& fileName = "ThermalUnitConverter") const;
protected:
// conversion factors
const T _conversionTemperature; // K
const T _conversionThermalDiffusivity; // m^2 / s
const T _conversionSpecificHeatCapacity; // J / kg K = m^2 / s^2 K
const T _conversionThermalConductivity; // W / m K = kg m / s^3 K
const T _conversionHeatFlux; // W / m^2 = kg / s^3
// physical units, e.g characteristic or reference values
const T _charPhysLowTemperature; // K
const T _charPhysHighTemperature; // K
const T _charPhysTemperatureDifference; // K
const T _physThermalExpansionCoefficient; // 1 / K
const T _physThermalDiffusivity; // m^2 / s
const T _physSpecificHeatCapacity; // J / kg K = m^2 / s^2 K
const T _physThermalConductivity; // W / m K = kg m / s^3 K
// lattice units, discretization parameters
const T _latticeThermalRelaxationTime; // -
private:
mutable OstreamManager clout;
};
} // namespace olb
#endif
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