Street inlet capture efficiency — FHWA HEC-22. More...

#include <cstdint>
#include <vector>

Include dependency graph for Inlet.hpp:

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

Classes
struct	openswmm::inlet::Geom
	Street / channel geometry seen by one inlet, in INTERNAL units. More...

struct	openswmm::inlet::Design
	One inlet design in INTERNAL units (legacy `TInletDesign`, inlet.c:66-74). More...

struct	openswmm::inlet::UsageParams
	The per-placement half of one usage row (legacy `TInlet` fields). More...

struct	openswmm::inlet::InletSoA

class	openswmm::inlet::InletSolver

Namespaces
namespace	openswmm

namespace	openswmm::inlet

Enumerations
enum class	openswmm::inlet::InletType : int { openswmm::inlet::GRATE = 0 , openswmm::inlet::CURB = 1 , openswmm::inlet::COMBO = 2 , openswmm::inlet::SLOTTED = 3 , openswmm::inlet::DROP_GRATE = 4 , openswmm::inlet::DROP_CURB = 5 , openswmm::inlet::CUSTOM = 6 }

enum class	openswmm::inlet::GrateType : int { openswmm::inlet::P_BAR_50 = 0 , openswmm::inlet::P_BAR_50x100 = 1 , openswmm::inlet::P_BAR_30 = 2 , openswmm::inlet::CURVED_VANE = 3 , openswmm::inlet::TILT_BAR_45 = 4 , openswmm::inlet::TILT_BAR_30 = 5 , openswmm::inlet::RETICULINE = 6 , openswmm::inlet::GENERIC = 7 }
	Legacy `enum GrateType` (inlet.c:124-127). More...

enum class	openswmm::inlet::Placement : int { openswmm::inlet::AUTOMATIC = 0 , openswmm::inlet::ON_GRADE = 1 , openswmm::inlet::ON_SAG = 2 }

enum class	openswmm::inlet::ThroatAngle : int { openswmm::inlet::HORIZONTAL = 0 , openswmm::inlet::INCLINED = 1 , openswmm::inlet::VERTICAL = 2 }
	Legacy `enum ThroatAngleType` (inlet.c:131) — `InletStore::curb_throat`. More...

enum class	openswmm::inlet::CurveKind : int { openswmm::inlet::UNRESOLVED = 0 , openswmm::inlet::DIVERSION = 1 , openswmm::inlet::RATING = 2 }
	`InletStore::curve_kind` codes for a CUSTOM design. More...

Functions
double	openswmm::inlet::getEo (double sr, double ts, double w)
	HEC-22 Eq(4-4) solved for Eo with Ts/w substituted for (T/w)−1 (inlet.c:1248).

double	openswmm::inlet::getFlowSpread (const Geom &g, double Q)
	Width of flow spread, HEC-22 Eq(4-2)/(4-6) (inlet.c:1200).

double	openswmm::inlet::getGutterFlowRatio (const Geom &g, double w)
	Ratio of the flow over width `w` to the total street flow, Eq(4-16) (inlet.c:1518).

double	openswmm::inlet::getGutterAreaRatio (const Geom &g, double Wg, double A)

double	openswmm::inlet::getSplashOverVelocity (int grate_type, double L)

double	openswmm::inlet::getGrateInletCapture (const Design &d, Geom &g, double Q)

double	openswmm::inlet::getCurbInletCapture (const Geom &g, double Q, double opening_length)
	On-grade curb-opening capture, Eq(4-22a)/(4-23)/(4-24) (inlet.c:1477).

double	openswmm::inlet::getOnGradeInletCapture (const Design &d, Geom &g, double Q, double depth)
	Capture of a single on-grade inlet — type dispatch + COMBO sweeper (inlet.c:1325).

double	openswmm::inlet::getOnGradeCapturedFlow (const Design &d, const UsageParams &u, Geom &g, double q, double depth)
	Total capture of an on-grade usage: `num_inlets` in series, both sides (inlet.c:1267).

void	openswmm::inlet::findOnSagGrateFlows (const Design &d, const Geom &g, double depth, double weir_flow, double orifice_flow)
	On-sag grate weir/orifice flows, Eq(4-26)/(4-27) (inlet.c:1644).

void	openswmm::inlet::findOnSagCurbFlows (const Design &d, const Geom &g, double depth, double L, double Qw, double Qo)

double	openswmm::inlet::getCurbOrificeFlow (double flow_depth, double opening_height, double opening_length, int throat_angle)
	Curb-opening orifice flow with the throat-angle head, Eq(4-31a) (inlet.c:1764).

double	openswmm::inlet::getOnSagSlottedFlow (const Design &d, double depth)
	On-sag slotted drain flow, Eq(4-32)/(4-33) (inlet.c:1785).

double	openswmm::inlet::getOnSagInletCapture (const Design &d, const Geom &g, double depth)
	Capture of a single on-sag inlet (inlet.c:1610).

double	openswmm::inlet::getOnSagCapturedFlow (const Design &d, const UsageParams &u, const Geom &g, double depth)
	Total capture of an on-sag usage: single inlet × `nsides · num_inlets` (inlet.c:1574).

double	openswmm::inlet::getCustomCapturedFlow (const UsageParams &u, const Geom &g, const Table &curve, int curve_kind, double q, double depth, double ucf_flow, double ucf_len)
	Capture of a CUSTOM inlet from its diversion / rating curve (inlet.c:1902).

double	openswmm::inlet::getInletArea (const Design &d, const UsageParams &u)
	Unclogged open area of one usage (ft²) — legacy getInletArea (inlet.c:1870).

Variables
constexpr double	openswmm::inlet::MIN_RUNOFF_FLOW = 0.001
	Legacy MIN_RUNOFF_FLOW (consts.h:203) — cfs.

constexpr double	openswmm::inlet::INLET_FUDGE = 0.0001
	Legacy FUDGE (consts.h:272).

constexpr double	openswmm::inlet::INLET_BIG = 1.0e10
	Legacy BIG (consts.h:118).

Detailed Description

Street inlet capture efficiency — FHWA HEC-22.

Inlet types: GRATE, CURB, COMBO, SLOTTED, DROP_GRATE, DROP_CURB, CUSTOM. On-grade capture uses splash-over velocity and frontal / side flow fractions (HEC-22 Eq. 4-16 … 4-24); on-sag capture uses the weir ↔ orifice transition (Eq. 4-26 … 4-33).

Two host kinds share one kernel and one statistics block (plans/INLET_JUNCTION_IMPLEMENTATION_PLAN_2026-09-05.md §2.1):

conduit-attribute usage — [INLET_USAGE], host = a STREET conduit, bypass node = that conduit's downstream node;
inlet junction — [INLET_JUNCTIONS], host = the node itself, approach flow from the attached street conduit(s).

The pure kernel functions below are transliterations of the legacy file-scope routines and carry the HEC-22 equation numbers; they take their state through inlet::Geom / inlet::Design / inlet::UsageParams instead of legacy's module-level shared variables, so they are directly unit-testable.

Note: Legacy reference: src/legacy/engine/inlet.c

Author: Caleb Buahin caleb.nosp@m..bua.nosp@m.hin@g.nosp@m.mail.nosp@m..com

License\n Apache-2.0

Classes

Namespaces

Enumerations

Functions

Variables

Detailed Description