Transient Navier-Stokes fluid-particles solver. More...

#include <navier_particles.hpp>

Collaboration diagram for mfem::navier::NavierParticles:

Classes
struct	FluidParticleIndices

struct	RecirculationBC_2D
	2D recirculation boundary condition struct More...

struct	ReflectionBC_2D
	2D wall reflection boundary condition struct More...

Public Member Functions
	NavierParticles (MPI_Comm comm, int num_particles, Mesh &m)
	Initialize NavierParticles with `num_particles` using fluid mesh `m` .

void	Setup (const real_t dt)
	Set initial timestep in time history array.

void	Step (const real_t dt, const ParGridFunction &u_gf, const ParGridFunction &w_gf)
	Step the particles in time.

void	InterpolateUW (const ParGridFunction &u_gf, const ParGridFunction &w_gf)
	Interpolate fluid velocity and vorticity onto current particles' location.

ParticleSet &	GetParticles ()
	Get reference to the active ParticleSet.

ParticleSet &	GetInactiveParticles ()
	Get reference to the inactive ParticleSet.

ParticleVector &	Kappa ()
	Get reference to the κ ParticleVector.

ParticleVector &	Zeta ()
	Get reference to the ζ ParticleVector.

ParticleVector &	Gamma ()
	Get reference to the γ ParticleVector.

ParticleVector &	U (int nm=0)
	Get reference to the fluid velocity-interpolated ParticleVector at time n - `nm` .

ParticleVector &	V (int nm=0)
	Get reference to the particle velocity ParticleVector at time n - `nm` .

ParticleVector &	W (int nm=0)
	Get reference to the fluid vorticity-interpolated ParticleVector at time n - `nm` .

ParticleVector &	X (int nm=0)
	Get reference to the position ParticleVector at time n - `nm` .

Array< int > &	Order ()
	Get reference to the order Array<int>.

void	Add2DReflectionBC (const Vector &line_start, const Vector &line_end, real_t e, bool invert_normal)
	Add a 2D wall reflective boundary condition.

void	Add2DRecirculationBC (const Vector &inlet_start, const Vector &inlet_end, bool invert_inlet_normal, const Vector &outlet_start, const Vector &outlet_end, bool invert_outlet_normal)
	Add a 2D recirculation / one-way periodic boundary condition.

Protected Types
using	BCVariant = std::variant<ReflectionBC_2D, RecirculationBC_2D>

Protected Member Functions
void	SetTimeIntegrationCoefficients ()
	Update beta_k and alpha_k using current dthist.

void	ParticleStep2D (const real_t &dt, int p)
	2D particle step for particle at index `p`

void	Apply2DReflectionBC (const ReflectionBC_2D &bc)
	Apply 2D reflection BCs to update particle positions and velocities.

void	Apply2DRecirculationBC (const RecirculationBC_2D &bc)
	Apply 2D recirculation BCs.

void	ApplyBCs ()
	Apply all BCs in bcs.

void	DeactivateLostParticles (bool findpts)
	Move any particles that have left the domain to the inactive ParticleSet.

Static Protected Member Functions
static void	Get2DNormal (const Vector &p1, const Vector &p2, bool inv_normal, Vector &normal)
	Given two 2D points, get the unit normal to the line connecting them.

static bool	Get2DSegmentIntersection (const Vector &s1_start, const Vector &s1_end, const Vector &s2_start, const Vector &s2_end, Vector &x_int, real_t t1_ptr=nullptr, real_t t2_ptr=nullptr)
	Given two 2D segments, get the intersection point if it exists.

Protected Attributes
ParticleSet	fluid_particles
	Active fluid particle set.

ParticleSet	inactive_fluid_particles

FindPointsGSLIB	finder

Array< real_t >	dthist {0.0, 0.0, 0.0}
	Timestep history.

std::array< Array< real_t >, 3 >	beta_k
	BDFk coefficients, k=1,2,3.

std::array< Array< real_t >, 3 >	alpha_k
	EXTk coefficients, k=1,2,3.

struct mfem::navier::NavierParticles::FluidParticleIndices	fp_idx

std::vector< BCVariant >	bcs
	std::vector of all boundary condition structs

Vector	up

Vector	vp

Vector	xpn

Vector	xp

Vector	r

Vector	C

Static Protected Attributes
static constexpr int	N_HIST = 4
	Number of timesteps to store (includes current)

Detailed Description

Transient Navier-Stokes fluid-particles solver.

This class implements a Lagrangian point particle tracking model from Dutta, Som (2017). Ph.D. Dissertation: Bulle-Effect and its implications for morphodynamics of river diversions. https://www.ideals.illinois.edu/items/102343.

In short, the particles are advanced in time by solving the ODE: dv/dt = κ(u-v) - γ ê + ζ (u-v) x ω, dx/dt = v, where x and v are the particle location and velocity, u is the fluid velocity at the particle location, ω is the fluid vorticity at the particle location, κ depends on the drag properties of the particle, ζ depends on the lift properties, and γ and ê depend on body forces such as gravity.

The model from Dutta et al. is general but this implementation is currently limited to 2D problems. Simple reflection and recirculation boundary conditions are also supported.

Definition at line 50 of file navier_particles.hpp.

Member Typedef Documentation

◆ BCVariant

using mfem::navier::NavierParticles::BCVariant = std::variant<ReflectionBC_2D, RecirculationBC_2D>

protected

Definition at line 113 of file navier_particles.hpp.

Constructor & Destructor Documentation

◆ NavierParticles()

mfem::navier::NavierParticles::NavierParticles	(	MPI_Comm	comm,
		int	num_particles,
		Mesh &	m )

Initialize NavierParticles with num_particles using fluid mesh m .

Definition at line 319 of file navier_particles.cpp.

Member Function Documentation

◆ Add2DRecirculationBC()

void mfem::navier::NavierParticles::Add2DRecirculationBC	(	const Vector &	inlet_start,
		const Vector &	inlet_end,
		bool	invert_inlet_normal,
		const Vector &	outlet_start,
		const Vector &	outlet_end,
		bool	invert_outlet_normal )

inline

Add a 2D recirculation / one-way periodic boundary condition.

Warning: Both normals must be facing into the domain. See Get2DNormal() for details on the normal direction.

Parameters

[in]	inlet_start	Inlet line segment start point.
[in]	inlet_end	Inlet line segment end point.
[in]	invert_inlet_normal	Invert direction of the inlet normal.
[in]	outlet_start	Outlet line segment start point.
[in]	outlet_end	Outlet line segment end point.
[in]	invert_outlet_normal	Invert direction of the outlet normal.

Definition at line 297 of file navier_particles.hpp.

◆ Add2DReflectionBC()

void mfem::navier::NavierParticles::Add2DReflectionBC	(	const Vector &	line_start,
		const Vector &	line_end,
		real_t	e,
		bool	invert_normal )

inline

Add a 2D wall reflective boundary condition.

Parameters

[in]	line_start	Wall line segment start point.
[in]	line_end	Wall line segment end point.
[in]	e	Boundary collision reconstitution constant. 1 for perfectly elastic.
[in]	invert_normal	True if left normal points out of domain. False if left normal points into domain.

Definition at line 280 of file navier_particles.hpp.

◆ Apply2DRecirculationBC()

void mfem::navier::NavierParticles::Apply2DRecirculationBC ( const RecirculationBC_2D & bc )

protected

Apply 2D recirculation BCs.

Definition at line 243 of file navier_particles.cpp.

◆ Apply2DReflectionBC()

void mfem::navier::NavierParticles::Apply2DReflectionBC ( const ReflectionBC_2D & bc )

protected

Apply 2D reflection BCs to update particle positions and velocities.

Definition at line 200 of file navier_particles.cpp.

◆ ApplyBCs()

void mfem::navier::NavierParticles::ApplyBCs ( )

protected

Apply all BCs in bcs.

Definition at line 298 of file navier_particles.cpp.

◆ DeactivateLostParticles()

void mfem::navier::NavierParticles::DeactivateLostParticles ( bool findpts )

protected

Move any particles that have left the domain to the inactive ParticleSet.

This method uses the FindPointsGSLIB object internal to the class to detect if particles are within the domain or not.

Parameters

[in] findpts If true, call FindPointsGSLIB::FindPoints prior to deactivation (if particle coordinates out of sync with FindPointsGSLIB)

Definition at line 435 of file navier_particles.cpp.

◆ Gamma()

ParticleVector & mfem::navier::NavierParticles::Gamma ( )

inline

Get reference to the γ ParticleVector.

Definition at line 229 of file navier_particles.hpp.

◆ Get2DNormal()

void mfem::navier::NavierParticles::Get2DNormal	(	const Vector &	p1,
		const Vector &	p2,
		bool	inv_normal,
		Vector &	normal )

staticprotected

Given two 2D points, get the unit normal to the line connecting them.

For inv_normal false, the normal is 90 degrees (CCW) from the line connecting p1 to p2 . For inv_normal true, the normal is 90 degrees (CW) from the line connecting p1 to p2 .

Definition at line 136 of file navier_particles.cpp.

◆ Get2DSegmentIntersection()

bool mfem::navier::NavierParticles::Get2DSegmentIntersection	(	const Vector &	s1_start,
		const Vector &	s1_end,
		const Vector &	s2_start,
		const Vector &	s2_end,
		Vector &	x_int,
		real_t *	t1_ptr = nullptr,
		real_t *	t2_ptr = nullptr )

staticprotected

Given two 2D segments, get the intersection point if it exists.

Specifically this function solves the following system of equations: r_1 = s1_start + t1*[s1_end - s1_start] r_2 = s2_start + t2*[s2_end - s2_start]

and then checks if 0<=t1<=1 and 0<=t2<=1 .

Parameters

[in]	s1_start	First line segment start point.
[in]	s1_end	First line segment end point.
[in]	s2_start	Second line segment start point.
[in]	s2_end	Second line segment end point.
[in]	x_int	Computed intersection point (if it exists)
[in]	t1_ptr	(Optional) Computed t1
[in]	t2_ptr	(Optional) Computed t2

Returns: true if intersection point exists, false otherwise

Definition at line 155 of file navier_particles.cpp.

◆ GetInactiveParticles()

ParticleSet & mfem::navier::NavierParticles::GetInactiveParticles ( )

inline

Get reference to the inactive ParticleSet.

Definition at line 214 of file navier_particles.hpp.

◆ GetParticles()

ParticleSet & mfem::navier::NavierParticles::GetParticles ( )

inline

Get reference to the active ParticleSet.

Definition at line 211 of file navier_particles.hpp.

◆ InterpolateUW()

void mfem::navier::NavierParticles::InterpolateUW	(	const ParGridFunction &	u_gf,
		const ParGridFunction &	w_gf )

Interpolate fluid velocity and vorticity onto current particles' location.

Parameters

[in]	u_gf	Fluid velocity on fluid mesh.
[in]	w_gf	Fluid vorticity on fluid mesh.

Definition at line 421 of file navier_particles.cpp.

◆ Kappa()

ParticleVector & mfem::navier::NavierParticles::Kappa ( )

inline

Get reference to the κ ParticleVector.

Definition at line 217 of file navier_particles.hpp.

◆ Order()

Array< int > & mfem::navier::NavierParticles::Order ( )

inline

Get reference to the order Array<int>.

Definition at line 268 of file navier_particles.hpp.

◆ ParticleStep2D()

void mfem::navier::NavierParticles::ParticleStep2D	(	const real_t &	dt,
		int	p )

protected

2D particle step for particle at index p

Definition at line 74 of file navier_particles.cpp.

◆ SetTimeIntegrationCoefficients()

void mfem::navier::NavierParticles::SetTimeIntegrationCoefficients ( )

protected

Update beta_k and alpha_k using current dthist.

Definition at line 23 of file navier_particles.cpp.

◆ Setup()

void mfem::navier::NavierParticles::Setup ( const real_t dt )

inline

Set initial timestep in time history array.

Definition at line 191 of file navier_particles.hpp.

◆ Step()

void mfem::navier::NavierParticles::Step	(	const real_t	dt,
		const ParGridFunction &	u_gf,
		const ParGridFunction &	w_gf )

Step the particles in time.

Parameters

[in]	dt
[in]	u_gf	Fluid velocity on fluid mesh.
[in]	w_gf	Fluid vorticity on fluid mesh.

Definition at line 369 of file navier_particles.cpp.

◆ U()

ParticleVector & mfem::navier::NavierParticles::U ( int nm = 0 )

inline

Get reference to the fluid velocity-interpolated ParticleVector at time n - nm .

Definition at line 237 of file navier_particles.hpp.

◆ V()

ParticleVector & mfem::navier::NavierParticles::V ( int nm = 0 )

inline

Get reference to the particle velocity ParticleVector at time n - nm .

Definition at line 244 of file navier_particles.hpp.

◆ W()

ParticleVector & mfem::navier::NavierParticles::W ( int nm = 0 )

inline

Get reference to the fluid vorticity-interpolated ParticleVector at time n - nm .

Definition at line 253 of file navier_particles.hpp.

◆ X()

ParticleVector & mfem::navier::NavierParticles::X ( int nm = 0 )

inline

Get reference to the position ParticleVector at time n - nm .

Definition at line 260 of file navier_particles.hpp.

◆ Zeta()

ParticleVector & mfem::navier::NavierParticles::Zeta ( )

inline

Get reference to the ζ ParticleVector.

Definition at line 223 of file navier_particles.hpp.

Member Data Documentation

◆ alpha_k

std::array<Array<real_t>, 3> mfem::navier::NavierParticles::alpha_k

protected

EXTk coefficients, k=1,2,3.

Definition at line 69 of file navier_particles.hpp.

◆ bcs

std::vector<BCVariant> mfem::navier::NavierParticles::bcs

protected

std::vector of all boundary condition structs

Definition at line 116 of file navier_particles.hpp.

◆ beta_k

std::array<Array<real_t>, 3> mfem::navier::NavierParticles::beta_k

protected

BDFk coefficients, k=1,2,3.

Definition at line 66 of file navier_particles.hpp.

◆ C

Vector mfem::navier::NavierParticles::C

protected

Definition at line 183 of file navier_particles.hpp.

◆ dthist

Array<real_t> mfem::navier::NavierParticles::dthist {0.0, 0.0, 0.0}

protected

Timestep history.

Definition at line 63 of file navier_particles.hpp.

◆ finder

FindPointsGSLIB mfem::navier::NavierParticles::finder

protected

Definition at line 60 of file navier_particles.hpp.

◆ fluid_particles

ParticleSet mfem::navier::NavierParticles::fluid_particles

protected

Active fluid particle set.

Definition at line 54 of file navier_particles.hpp.

◆ fp_idx

struct mfem::navier::NavierParticles::FluidParticleIndices mfem::navier::NavierParticles::fp_idx

protected

◆ inactive_fluid_particles

ParticleSet mfem::navier::NavierParticles::inactive_fluid_particles

protected

Inactive fluid particle set. Particles that leave the domain are added here.

Definition at line 58 of file navier_particles.hpp.

◆ N_HIST

int mfem::navier::NavierParticles::N_HIST = 4

staticconstexprprotected

Number of timesteps to store (includes current)

Definition at line 72 of file navier_particles.hpp.

◆ r

Vector mfem::navier::NavierParticles::r

mutableprotected

Definition at line 183 of file navier_particles.hpp.

◆ up

Vector mfem::navier::NavierParticles::up

mutableprotected

Definition at line 182 of file navier_particles.hpp.

◆ vp

Vector mfem::navier::NavierParticles::vp

protected

Definition at line 182 of file navier_particles.hpp.

◆ xp

Vector mfem::navier::NavierParticles::xp

protected

Definition at line 182 of file navier_particles.hpp.

◆ xpn

Vector mfem::navier::NavierParticles::xpn

protected

Definition at line 182 of file navier_particles.hpp.

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

miniapps/fluids/navier/navier_particles.hpp
miniapps/fluids/navier/navier_particles.cpp

Classes

Public Member Functions

Protected Types

Protected Member Functions

Static Protected Member Functions

Protected Attributes

Static Protected Attributes

Detailed Description

Member Typedef Documentation

◆ BCVariant

Constructor & Destructor Documentation

◆ NavierParticles()

Member Function Documentation

◆ Add2DRecirculationBC()

◆ Add2DReflectionBC()

◆ Apply2DRecirculationBC()

◆ Apply2DReflectionBC()

◆ ApplyBCs()

◆ DeactivateLostParticles()

◆ Gamma()

◆ Get2DNormal()

◆ Get2DSegmentIntersection()

◆ GetInactiveParticles()

◆ GetParticles()

◆ InterpolateUW()

◆ Kappa()

◆ Order()

◆ ParticleStep2D()

◆ SetTimeIntegrationCoefficients()

◆ Setup()

◆ Step()

◆ U()

◆ V()

◆ W()

◆ X()

◆ Zeta()

Member Data Documentation

◆ alpha_k

◆ bcs

◆ beta_k

◆ C

◆ dthist

◆ finder

◆ fluid_particles

◆ fp_idx

◆ inactive_fluid_particles

◆ N_HIST

◆ r

◆ up

◆ vp

◆ xp

◆ xpn