coala_interface.hpp File Reference

COALA dust coagulation helpers for a DG \(k=0\) (piecewise-constant) basis. More...

#include "shambase/assert.hpp"
#include "shambase/mdspan_concepts.hpp"
#include <experimental/mdspan>
#include <concepts>

Include dependency graph for coala_interface.hpp:

This graph shows which files directly or indirectly include this file:

Go to the source code of this file.

Functions
template<class T> requires requires(decltype(rho_dust) rd, int j) { { rd(j) } -> std::same_as<T>; }
void	shamphys::compute_gij_k0 (auto &&rho_dust, T rho_eps, shambase::is_mdspan_rank< 1 > auto massgrid, shambase::is_mdspan_rank< 1 > auto gij)
	Build \(g_j\) coefficients on the piecewise-constant DG basis ( \(k=0\)).
template<class Func> requires requires(Func f, int a, int b) { { f(a, b) }; }
void	shamphys::compute_flux_coag_k0_kdv (int nbins, shambase::is_mdspan_rank< 1 > auto gij, shambase::is_mdspan_rank< 3 > auto tensor_tabflux_coag, Func &&dv, shambase::is_mdspan_rank< 1 > auto flux)
	Coagulation flux at bin right edges for a ballistic kernel ( \(k=0\)).
void	shamphys::coala_flux_diff (shambase::is_mdspan_rank< 1 > auto flux, shambase::is_mdspan_rank< 1 > auto S_coag)
	Convert interface fluxes to a mass-bin coagulation source term.
template<class T, class FuncDv, class FuncRhoDust>
void	shamphys::coala_k0_source_term (int nbins, FuncDv &&dv, FuncRhoDust &&rho_dust, T rho_eps, shambase::is_mdspan_rank< 1 > auto massgrid, shambase::is_mdspan_rank< 3 > auto tabflux_coag, shambase::is_mdspan_rank< 1 > auto gij, shambase::is_mdspan_rank< 1 > auto flux, shambase::is_mdspan_rank< 1 > auto S_coag)

Detailed Description

COALA dust coagulation helpers for a DG \(k=0\) (piecewise-constant) basis.

Author

Maxime Lombart (maxim.nosp@m.e.lo.nosp@m.mbart.nosp@m.@cea.nosp@m..fr)

Timothée David–Cléris (tim.s.nosp@m.hamr.nosp@m.ock@p.nosp@m.roto.nosp@m.n.me)

C++ counterparts of the COALA Python routines used to build dust coagulation source terms in the conservative form of the Smoluchowski equation (Lombart et al., 2021). The reference implementation lives in src/pylib/shamrock/external/coala/interface_coala_shamrock.py and src/pylib/shamrock/external/coala/generate_flux_intflux.py.

Only the coagulation flux with \(k=0\) approximation.

Definition in file coala_interface.hpp.

Function Documentation

coala_flux_diff()

void shamphys::coala_flux_diff	(	shambase::is_mdspan_rank< 1 > auto	flux,
		shambase::is_mdspan_rank< 1 > auto	S_coag )

Convert interface fluxes to a mass-bin coagulation source term.

Applies the DG \(k=0\) divergence operator (finite difference across bin boundaries) to obtain the source term \(S_{\rm coag}\) in the conservative form of the Smoluchowski equation:

\[ S_{\rm coag}[0] = -\mathrm{flux}[0], \qquad S_{\rm coag}[j] = \mathrm{flux}[j-1] - \mathrm{flux}[j] \quad (j \ge 1) \]

Parameters

flux	Rank-1 view of coagulation fluxes at bin right edges
S_coag	Rank-1 output view of the same length; filled in place

Definition at line 152 of file coala_interface.hpp.

coala_k0_source_term()

template<class T, class FuncDv, class FuncRhoDust>

void shamphys::coala_k0_source_term	(	int	nbins,
		FuncDv &&	dv,
		FuncRhoDust &&	rho_dust,
		T	rho_eps,
		shambase::is_mdspan_rank< 1 > auto	massgrid,
		shambase::is_mdspan_rank< 3 > auto	tabflux_coag,
		shambase::is_mdspan_rank< 1 > auto	gij,
		shambase::is_mdspan_rank< 1 > auto	flux,
		shambase::is_mdspan_rank< 1 > auto	S_coag )

Definition at line 164 of file coala_interface.hpp.

compute_flux_coag_k0_kdv()

template<class Func>
requires requires(Func f, int a, int b) { { f(a, b) }; }

void shamphys::compute_flux_coag_k0_kdv ( int nbins, shambase::is_mdspan_rank< 1 > auto gij, shambase::is_mdspan_rank< 3 > auto tensor_tabflux_coag, Func && dv, shambase::is_mdspan_rank< 1 > auto flux )

inline

Coagulation flux at bin right edges for a ballistic kernel ( \(k=0\)).

Evaluates the flux approximation at the right boundary of each mass bin, \(\mathrm{flux}[j] \approx F(m_{j+1/2})\), by summing over all bin pairs \((l, m)\):

\[ \mathrm{flux}[j] = \sum_{l,m} \mathrm{tensor\_tabflux\_coag}[j,l,m]\, \mathrm{dv}(l,m)\, g_l\, g_m \]

Equivalent to the NumPy contraction einsum("jlm,lm,l,m->j", tensor_tabflux_coag, dv, gij, gij).

gij, tensor_tabflux_coag and flux are expected to share the same scalar element type.

Template Parameters

Func	Callable invoked as dv(l, m) returning the differential velocity between bins \(l\) and \(m\) (e.g. \(|\mathbf{v}_m - \mathbf{v}_l|\))

Parameters

nbins	Number of dust mass bins
gij	Rank-1 std::mdspan (shambase::is_mdspan_rank<1>) of DG coefficients \(g_l\); extent nbins
tensor_tabflux_coag	Rank-3 std::mdspan (shambase::is_mdspan_rank<3>) of precomputed coagulation flux entries; extents nbins (\times) nbins (\times) nbins
dv	Pair-wise differential-velocity callable
flux	Rank-1 std::mdspan (shambase::is_mdspan_rank<1>) of output fluxes; extent nbins, written in place

Definition at line 107 of file coala_interface.hpp.

compute_gij_k0()

template<class T>
requires requires(decltype(rho_dust) rd, int j) { { rd(j) } -> std::same_as<T>; }

void shamphys::compute_gij_k0 ( auto && rho_dust, T rho_eps, shambase::is_mdspan_rank< 1 > auto massgrid, shambase::is_mdspan_rank< 1 > auto gij )

inline

Build \(g_j\) coefficients on the piecewise-constant DG basis ( \(k=0\)).

For each mass bin \(j\), converts the dust density to the polynomial coefficient \(g_j = \rho_{\rm d,j} / \Delta m_j\) when \(\rho_{\rm d,j} > \rho_{\rm eps}\), and sets \(g_j = 0\) otherwise, with \Delta m_j = massgrid[j+1] - massgrid[j] the bin width from consecutive mass-grid edges.

Template Parameters

T	Floating-point scalar type; rho_dust must satisfy rho_dust(j) -> T, and massgrid / gij must be rank-1 std::mdspan with element type T

Parameters

rho_dust	Callable invoked as rho_dust(j) returning dust density in bin \(j\)
rho_eps	Density threshold below which \(g_j\) is set to zero
massgrid	Rank-1 std::mdspan (shambase::is_mdspan_rank<1>) of bin-edge masses; extent must be gij.extent(0) + 1
gij	Rank-1 std::mdspan (shambase::is_mdspan_rank<1>) of DG coefficients; one entry per bin, written in place

Definition at line 54 of file coala_interface.hpp.