collocated_varrho_point.hpp File Reference

flow — the POINTWISE formulas of the collocated variable-density ABC pair (doc/collocated_varrho_forces.md §4.1, §4.9 L5). More...

#include <Kokkos_Core.hpp>

Go to the source code of this file.

Namespaces
namespace	peclet
namespace	peclet::flow
namespace	peclet::flow::varrho

Functions
double	peclet::flow::varrho::faceMassWeighted (double uL, double uR, double rL, double rR)
double	peclet::flow::varrho::cellFromFaces (double aLo, double aHi, double oLo, double oHi)
double	peclet::flow::varrho::weightSum (double oLo, double oHi)

Detailed Description

flow — the POINTWISE formulas of the collocated variable-density ABC pair (doc/collocated_varrho_forces.md §4.1, §4.9 L5).

Container-free on purpose: no Views, no solver state, KOKKOS_INLINE_FUNCTION only. They are the three places where the collocated variable-density scheme's WEIGHTS live, so that promoting them to peclet::core::scheme (for amr's multiphase package, §13 / Q10) is a file move, and so that a change of reconstruction weights (the ghost scheme's one-sided pair, amr's coarse-fine weights) changes these functions and nothing else.

The pair they define (face j of component c separates cells j - s and j):

• centre -> face, the projection's constraint: u_f = (rho_L u_L + rho_R u_R) / (rho_L + rho_R) (faceMassWeighted; the MOMENTUM-weighted map. Only with it is the pressure force exactly -M^{-1} C^T, M Gamma = -(D O Pi_rho)^T for any openness 0 <= o <= 1 — §4.3);
• face -> cell, the pressure force and the projection's cell correction: a_c = ½ (o_lo a_lo + o_hi a_hi) (cellFromFaces; the face accelerations a are the bracket [F_f - w G_f P] / rho_f WITHOUT the openness, which this reconstruction applies once);
• the weight sum of that reconstruction, W = ½ (o_lo + o_hi) (weightSum), which multiplies a per-cell volumetric force so that f = rho g balances the pressure part rho_c sum r_f g exactly next to a wall (§4.5).

L1: openness is a multiplicative WEIGHT, never a predicate. With o in {0, 1} (this package: all-fluid, domain walls) it is bitwise what a predicate gives; with fractional apertures it is the aperture-adjoint pair. cellFromFaces and weightSum must always be called with the SAME two openness reads.

Definition in file collocated_varrho_point.hpp.