Implements 1d radial unsteady heat transfer. More...

#include <unsteady.hpp>

Inheritance diagram for UnsteadyHeatTransfer:

Public Member Functions
	UnsteadyHeatTransfer (const double diameter, const PipeWall &pipeWall, const double burialDepth, const BurialMedium &burialMedium, const AmbientFluid &ambientFluid)
	Construct from complete description of pipeline and surroundings. More...

virtual HeatTransferState	evaluate (const HeatTransferState &current, const double timeStep, const double ambientTemperature, const double gasPressure, const double gasTemperature, const double gasReynoldsNumber, const double gasHeatCapacity, const double gasViscosity) const override
	Evaluate 1d radial unsteady heat transfer model. More...

HeatTransferState	evaluateInternal (const arma::vec &shellTemperature, const double timeStep, const double ambientTemperature, const double gasPressure, const double gasTemperature, const double gasReynoldsNumber, const double gasHeatCapacity, const double gasViscosity) const
	Internal method used for evaluating the unsteady heat transfer model. More...

HeatTransferState	thermalizeToSteadyState (const double ambientTemperature, const double gasPressure, const double gasTemperature, const double gasReynoldsNumber, const double gasHeatCapacity, const double gasViscosity) const
	Thermalize the unsteady heat transfer model to steady state. More...

Public Member Functions inherited from RadialHeatTransfer
	RadialHeatTransfer (const double diameter, const PipeWall &pipeWall, const double burialDepth, const BurialMedium &burialMedium, const AmbientFluid &ambientFluid)
	Constructor that sets up the discretization of the pipe surroundings. More...

double	calculateOuterFilmCoefficient () const
	Calculate the outer film coefficient. Basically a wrapper around utils::calcOuterWallFilmCoefficient(const double, const AmbientFluid&) using the proper arguments. More...

virtual arma::uword	size () const
	The number of discretization elements.

virtual HeatTransferState	makeState (const double heatFlux) const override
	Make instance of HeatTransferState from heat flux. Override. More...

virtual HeatTransferState	makeState (const double heatFlux, const double gasTemperature, const double ambientTemperature) const override
	Make instance of HeatTransferState from heat flux. Override. More...

Public Member Functions inherited from HeatTransferBase
virtual	~HeatTransferBase ()

Private Member Functions
arma::vec	solveEquations (const arma::vec &shellTemperature, const double timeStep, const double gasPressure, const double gasTemperature, const double ambientTemperature, const double gasReynoldsNumber, const double gasHeatCapacity, const double gasViscosity) const
	Internal (private) method used for solving the equations in the 1d radial unsteady heat transfer model. More...

Private Attributes
arma::vec	m_heatTransferCoefficient

Additional Inherited Members
Protected Attributes inherited from RadialHeatTransfer
double	m_diameter
	Pipe inner diameter [m].

double	m_burialDepth
	Distance from top of pipe to top of burial medium [m].

BurialMedium	m_burialMedium

AmbientFluid	m_ambientFluid
	Description of the fluid surrounding the pipeline.

arma::vec	m_width
	Width of each discretization shell [m].

arma::vec	m_conductivity
	Thermal conductivity of each discretization shell [W/(m K)].

arma::vec	m_density
	Density of each discretization shell [kg/m3].

arma::vec	m_heatCapacity
	Heat capacity of each discretization shell ( \(c_p\)) [J/(kg K)].

arma::uvec	m_isBurialLayer

arma::vec	m_crossSection
	Area/cross-section of each shell [m2].

arma::vec	m_ri
	Inner radius [m].

arma::vec	m_ro
	Outer radius [m].

Detailed Description

Implements 1d radial unsteady heat transfer.

This is documented in Jan Fredrik Helgaker's PhD thesis and in

Constructor & Destructor Documentation

◆ UnsteadyHeatTransfer()

UnsteadyHeatTransfer::UnsteadyHeatTransfer	(	const double	diameter,
		const PipeWall &	pipeWall,
		const double	burialDepth,
		const BurialMedium &	burialMedium,
		const AmbientFluid &	ambientFluid
	)

Construct from complete description of pipeline and surroundings.

Parameters

diameter	Inner diameter [m]
pipeWall	PipeWall instance
burialDepth	Distance from top of pipe to top of burial medium [m]
burialMedium	BurialMedium instance
ambientFluid	AmbientFluid instanc.

Member Function Documentation

◆ evaluate()

virtual HeatTransferState UnsteadyHeatTransfer::evaluate	(	const HeatTransferState &	current,
		const double	timeStep,
		const double	ambientTemperature,
		const double	gasPressure,
		const double	gasTemperature,
		const double	gasReynoldsNumber,
		const double	gasHeatCapacity,
		const double	gasViscosity
	)		const

overridevirtual

Evaluate 1d radial unsteady heat transfer model.

Operates on a HeatTransferState and returns a new HeatTransferState. Requires the discretization temperature HeatTransferState::m_temperature.

Parameters

current	Current HeatTransferState
timeStep	Time step [s]
ambientTemperature	Ambient temperature [K]
gasPressure	Gas pressure [Pa]
gasTemperature	Gas temperature [K]
gasReynoldsNumber	Reynolds number of gas [-]
gasHeatCapacity	Gas heat capacity ( \(c_p\)) [J/(kg K)]
gasViscosity	Gas dynamic viscosity [Pa s] = [kg/m*s]

Returns: HeatTransferState with new heat flux.

Implements HeatTransferBase.

◆ evaluateInternal()

HeatTransferState UnsteadyHeatTransfer::evaluateInternal	(	const arma::vec &	shellTemperature,
		const double	timeStep,
		const double	ambientTemperature,
		const double	gasPressure,
		const double	gasTemperature,
		const double	gasReynoldsNumber,
		const double	gasHeatCapacity,
		const double	gasViscosity
	)		const

Internal method used for evaluating the unsteady heat transfer model.

This is exposed for testing purposes. We typically use pointers anyway, so this is not accessible without casting to UnsteadyHeatTransfer.

Parameters

shellTemperature	The temperature of each discretization layer [K]
timeStep	Time step [s]
ambientTemperature	Ambient temperature [K]
gasPressure	Gas pressure [Pa]
gasTemperature	Gas temperature [K]
gasReynoldsNumber	Reynolds number of gas [-]
gasHeatCapacity	Gas heat capacity ( \(c_p\)) [J/(kg K)]
gasViscosity	Gas dynamic viscosity [Pa s] = [kg/m*s]

Returns: HeatTransferState with new heat flux.

◆ solveEquations()

arma::vec UnsteadyHeatTransfer::solveEquations	(	const arma::vec &	shellTemperature,
		const double	timeStep,
		const double	gasPressure,
		const double	gasTemperature,
		const double	ambientTemperature,
		const double	gasReynoldsNumber,
		const double	gasHeatCapacity,
		const double	gasViscosity
	)		const

private

Internal (private) method used for solving the equations in the 1d radial unsteady heat transfer model.

Parameters

shellTemperature	The temperature of each discretization layer [K]
timeStep	Time step [s]
ambientTemperature	Ambient temperature [K]
gasPressure	Gas pressure [Pa]
gasTemperature	Gas temperature [K]
gasReynoldsNumber	Reynolds number of gas [-]
gasHeatCapacity	Gas heat capacity ( \(c_p\)) [J/(kg K)]
gasViscosity	Gas dynamic viscosity [Pa s] = [kg/m*s]

Returns: HeatTransferState with new heat flux.

◆ thermalizeToSteadyState()

HeatTransferState UnsteadyHeatTransfer::thermalizeToSteadyState	(	const double	ambientTemperature,
		const double	gasPressure,
		const double	gasTemperature,
		const double	gasReynoldsNumber,
		const double	gasHeatCapacity,
		const double	gasViscosity
	)		const

Thermalize the unsteady heat transfer model to steady state.

This just performs an infinite time step to find the temperature distribution in the discretization layers at steady state. This could also be done analytically, if we had the analytic solution.

Parameters

ambientTemperature	Ambient temperature [K]
gasPressure	Gas pressure [Pa]
gasTemperature	Gas temperature [K]
gasReynoldsNumber	Reynolds number of gas [-]
gasHeatCapacity	Gas heat capacity ( \(c_p\)) [J/(kg K)]
gasViscosity	Gas dynamic viscosity [Pa s] = [kg/m*s]

Returns: HeatTransferState with new heat flux.

Member Data Documentation

◆ m_heatTransferCoefficient

arma::vec UnsteadyHeatTransfer::m_heatTransferCoefficient

private

Heat transfer coefficient for each discretization layer. This is the k_i from eq. (2.26) in JFH PhD thesis.

The documentation for this class was generated from the following file:

D:/Code/transient-pipeline-flow-gh-pages/src/heattransfer/unsteady.hpp

Public Member Functions

Private Member Functions

Private Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ UnsteadyHeatTransfer()

Member Function Documentation

◆ evaluate()

◆ evaluateInternal()

◆ solveEquations()

◆ thermalizeToSteadyState()

Member Data Documentation

◆ m_heatTransferCoefficient