openswmm::twoD::diffusive Namespace Reference

Functions
OPENSWMM_KERNEL_FN double	faceDischarge (double hf, double slope, double nf, double s_eps) noexcept
	Manning quasi-steady face discharge (m²/s, positive L→R) for face depth hf, surface slope S = (η_R − η_L)·inv_dx (positive ⇒ flow R→L), face Manning n_f and slope floor s_eps.
OPENSWMM_KERNEL_FN double	cellDiffusiveDt (double alpha, double lchar, double h, double n, double slope_abs, double s_eps) noexcept
	Explicit-diffusion step bound for a cell of characteristic length L, depth h, Manning n and the largest face slope |S| among its faces (floored at s_eps): Δt = α · L² · n · √S / (4 · h^{5/3}). Returns a huge value for a dry cell.

Function Documentation

cellDiffusiveDt()

OPENSWMM_KERNEL_FN double openswmm::twoD::diffusive::cellDiffusiveDt ( double alpha, double lchar, double h, double n, double slope_abs, double s_eps )

noexcept

Explicit-diffusion step bound for a cell of characteristic length L, depth h, Manning n and the largest face slope |S| among its faces (floored at s_eps): Δt = α · L² · n · √S / (4 · h^{5/3}). Returns a huge value for a dry cell.

Parameters

[in]	alpha	Finite positive Courant/diffusion safety factor, dimensionless.
[in]	lchar	Finite positive cell characteristic length, m.
[in]	h	Finite nonnegative mean depth, m; nonpositive selects the dry sentinel.
[in]	n	Finite positive Manning coefficient, s/m^(1/3).
[in]	slope_abs	Finite nonnegative largest face-slope magnitude, dimensionless.
[in]	s_eps	Finite positive dimensionless slope floor.

Returns

Explicit diffusion step bound in seconds, or 1e30 s for a dry cell.

Note

Pure host/device arithmetic: no allocation, exceptions, retained pointers or model state mutation. Caller supplies finite valid physical inputs; no general validation.

faceDischarge()

OPENSWMM_KERNEL_FN double openswmm::twoD::diffusive::faceDischarge ( double hf, double slope, double nf, double s_eps )

noexcept

Manning quasi-steady face discharge (m²/s, positive L→R) for face depth hf, surface slope S = (η_R − η_L)·inv_dx (positive ⇒ flow R→L), face Manning n_f and slope floor s_eps.

Parameters

[in]	hf	Finite face flow depth, m; nonpositive returns zero.
[in]	slope	Signed dimensionless (eta_R-eta_L)/normal distance; positive drives right-to-left.
[in]	nf	Finite positive Manning coefficient, s/m^(1/3); nonpositive returns zero.
[in]	s_eps	Finite positive dimensionless slope-magnitude floor.

Returns

Unit-width discharge in m2/s, positive left-to-right; exactly zero for zero slope.

Note

Pure host/device arithmetic: no allocation, exceptions, retained pointers or model state mutation. Caller supplies finite valid physical inputs; no general validation.