SyntheticInflow Class Reference

Synthetic turbulence for one nscbc_inlet: the digital filter of Klein, Sadiki & Janicka (2003), with the inlet's Reynolds stress imposed by the Cholesky factor of Lund, Wu & Squires (1998) (docs/design/synthetic_inflow.md). More...

#include <synthetic_inflow.h>

Public Member Functions
	SyntheticInflow (const toml::value &boundary, const std::string &where, uint64_t stream, const Mesh &mesh, const std::vector< uint32_t > &faces, const std::vector< int32_t > &char_index)
void	fill (double t, const Kokkos::View< rtype *[N_DIM]> &target)
	Write the target velocity (mean plus fluctuation) of the inlet's faces at time t into target(k).
std::string	summary () const
	One-line description for the run log.
double	time_spacing () const
	Time between filtered planes.
double	convection_velocity () const
	Convection velocity of Taylor's hypothesis.
uint32_t	plane (int64_t m)
void	random_plane (int64_t m, uint32_t slot)
void	time_filter (int64_t m, uint32_t slot)
void	net_flux (uint32_t slot)

Detailed Description

Synthetic turbulence for one nscbc_inlet: the digital filter of Klein, Sadiki & Janicka (2003), with the inlet's Reynolds stress imposed by the Cholesky factor of Lund, Wu & Squires (1998) (docs/design/synthetic_inflow.md).

Unit-variance random numbers on an auxiliary uniform grid on the inlet plane (one plane per generator time step) are filtered with Gaussian kernels along the two transverse directions and in time, the third direction of Klein's filter by Taylor's hypothesis. Face centroids interpolate the filtered field (bilinear in space, linear in time), and the interpolated value is divided by its exact standard deviation, so that the fluctuation of every face has unit variance before the Cholesky factor scales it.

Random numbers come from a counter-based hash of (seed, inlet, component, grid point, plane): every plane is a function of its index alone, so the field at time t does not depend on the number of ranks, on the time steps taken before, or on a restart; the generator has no state to store.

Constructor & Destructor Documentation

SyntheticInflow()

SyntheticInflow::SyntheticInflow	(	const toml::value &	boundary,
		const std::string &	where,
		uint64_t	stream,
		const Mesh &	mesh,
		const std::vector< uint32_t > &	faces,
		const std::vector< int32_t > &	char_index
	)

Parameters

boundary	The [[boundaries]] entry (with its turbulence table).
where	Its name for messages.
stream	Random stream of the inlet (its index among the boundaries).
mesh	Mesh.
faces	The inlet's faces on this rank.
char_index	Index of each face into BoundaryData::char_*.

Member Function Documentation

convection_velocity()

double SyntheticInflow::convection_velocity ( ) const

inline

Convection velocity of Taylor's hypothesis.

fill()

void SyntheticInflow::fill	(	double	t,
		const Kokkos::View< rtype *[N_DIM]> &	target
	)

Write the target velocity (mean plus fluctuation) of the inlet's faces at time t into target(k).

net_flux()

void SyntheticInflow::net_flux

(

uint32_t

slot

)

plane()

uint32_t SyntheticInflow::plane

(

int64_t

m

)

random_plane()

void SyntheticInflow::random_plane	(	int64_t	m,
		uint32_t	slot
	)

summary()

std::string SyntheticInflow::summary ( ) const

inline

One-line description for the run log.

time_filter()

void SyntheticInflow::time_filter	(	int64_t	m,
		uint32_t	slot
	)

time_spacing()

double SyntheticInflow::time_spacing ( ) const

inline

Time between filtered planes.

---

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

• /home/runner/work/mallard/mallard/mallard/src/boundary/synthetic_inflow.h
• /home/runner/work/mallard/mallard/mallard/src/boundary/synthetic_inflow.cpp