# Magnetic Flux Ontology — Flow Algebra
URL: https://kirethresearch.org/booksai-core/ontologies/mathematical-ontologies/measurement-units-ontologies/electromagnetic-measurements/magnetic-flux-ontology.html
FLOW MagneticFluxOntology {
DOMAIN:
Mathematical Ontologies
-> Measurement & Units Ontologies
-> Electromagnetic Measurements
-> Magnetic Flux Ontology
PURPOSE:
Represent magnetic flux as a measurable scalar surface-integral quantity describing the magnetic flux density passing through an oriented surface, including magnitude, sign, surface orientation, units, dimensional structure, flux linkage, electromagnetic induction, Faraday's law, closed-surface behaviour, measurement methods, uncertainty, and distinctions from magnetic flux density and magnetic field strength.
ENTITY MagneticFlux {
TYPE: DerivedElectromagneticQuantity
SYMBOL: Phi_B
DIMENSION: M * L^2 * T^-2 * I^-1
SI_UNIT: weber
SI_SYMBOL: Wb
DEFINITION:
magnetic_flux := surface_integral(MagneticFluxDensity dot DifferentialAreaVector)
GENERAL_FORM:
Phi_B = integral_S(B dot dA)
UNIFORM_PLANAR_FORM:
Phi_B = B*A*cos(theta)
PROPERTIES:
is_scalar_surface_integral_result
has_sign_relative_to_surface_orientation
has_value
has_unit
has_dimension
depends_on_surface
depends_on_surface_orientation
may_vary_with_time
may_have_uncertainty
}
ENTITY MagneticFluxDensity {
TYPE: VectorFieldPhysicalQuantity
SYMBOL: B
DIMENSION: M * T^-2 * I^-1
SI_UNIT: tesla
SI_SYMBOL: T
RELATION:
MagneticFlux = surface_integral(B dot dA)
}
ENTITY AreaVector {
TYPE: OrientedGeometricQuantity
SYMBOL: A_vector
DIMENSION: L^2
DEFINITION:
area_magnitude_times_unit_surface_normal
RELATION:
B dot AreaVector -> MagneticFlux
FOR uniform_planar_field_case
}
ENTITY MagneticFieldStrength {
TYPE: VectorFieldPhysicalQuantity
SYMBOL: H
SI_UNIT: ampere_per_metre
SI_SYMBOL: A/m
RELATION:
B = mu*H
UNDER linear_isotropic_material_context
}
ENTITY ElectromotiveForce {
TYPE: DerivedElectromagneticQuantity
SYMBOL: emf
SI_UNIT: volt
SI_SYMBOL: V
RELATION:
emf = -d(MagneticFluxLinkage)/dt
}
UNIT_SYSTEM {
SI {
canonical_unit: weber
symbol: Wb
equivalence:
1 Wb = 1 T*m^2
1 Wb = 1 V*s
1 Wb = 1 kg*m^2/(A*s^2)
}
COMMON_ALTERNATIVES {
milliweber
microweber
nanoweber
maxwell
}
COMMON_CONVERSION:
1 Wb = 1e8 maxwell
1 maxwell = 1e-8 Wb
CONVERSION_RULE:
magnetic_flux_value(target_unit)
= magnetic_flux_value(source_unit)
* conversion_factor(source_unit, target_unit)
}
CLASSIFICATION {
by surface:
open_surface_flux
closed_surface_flux
by field_geometry:
uniform_field_flux
nonuniform_field_flux
by time:
static_magnetic_flux
time_varying_magnetic_flux
by circuit_context:
single_turn_flux
flux_linkage
leakage_flux
mutual_flux
}
SURFACE_INTEGRAL_MODEL {
GENERAL:
Phi_B = integral_S(B dot n_hat dA)
UNIFORM_FIELD_PLANAR_SURFACE:
Phi_B = B*A*cos(theta)
ANGLE:
theta = angle_between_B_and_surface_normal
SPECIAL_CASES:
B_parallel_to_surface_normal:
abs(Phi_B) = B*A
B_perpendicular_to_surface_normal:
Phi_B = 0
RULE:
angle_is_with_surface_normal
NOT directly_with_surface_plane
}
ORIENTATION_MODEL {
surface_normal:
n_hat
positive_flux:
B_component_along_positive_normal > 0
negative_flux:
B_component_opposite_positive_normal > 0
orientation_reversal:
n_hat -> -n_hat
causes Phi_B -> -Phi_B
RULE:
surface_orientation MUST be preserved
for signed_flux_and_induction_reasoning
}
GAUSS_MAGNETISM_MODEL {
DIFFERENTIAL_FORM:
divergence(B) = 0
CLOSED_SURFACE_FORM:
closed_surface_integral(B dot dA) = 0
CONSEQUENCE:
net_magnetic_flux_through_any_closed_surface = 0
in_standard_classical_electromagnetism
RULE:
zero_net_closed_surface_flux
DOES_NOT imply B = 0 on_surface
}
FARADAY_INDUCTION_MODEL {
SINGLE_LOOP:
emf = -dPhi_B/dt
WHEN Phi_B represents_flux_through_loop_with_consistent_orientation
FLUX_LINKAGE_FORM:
emf = -d(lambda_B)/dt
N_TURN_IDEAL_COIL:
lambda_B = N*Phi_B
WHEN each_turn_links_same_flux
LENZ_SIGN:
negative_sign encodes_induced_response_opposing_flux_change
under_consistent_loop_orientation
RULE:
orientation_of_loop_and_surface_normal
MUST be consistent_with_emf_sign_convention
}
FLUX_LINKAGE_MODEL {
ENTITY MagneticFluxLinkage {
SYMBOL: lambda_B
SI_UNIT: weber_turn
COMMON_DIMENSIONAL_EQUIVALENCE: weber
}
GENERAL:
lambda_B = sum(flux_linked_by_each_turn)
IDEAL_N_TURN:
lambda_B = N*Phi_B
INDUCTANCE_RELATION:
lambda_B = L*I
UNDER linear_inductor_context
RULE:
magnetic_flux_and_flux_linkage
MUST_NOT be treated_as_identical_when_turn_count_or_linkage_differs
}
INDUCTANCE_MODEL {
SELF_INDUCTANCE:
L = lambda_B/I
WHEN I != 0 AND linear_context
IDEAL_SINGLE_FLUX_N_TURN:
L = N*Phi_B/I
INDUCED_VOLTAGE:
v = -d(lambda_B)/dt
according_to_orientation_and_passive_sign_convention
RULE:
nonlinear_magnetic_materials MAY require differential_or_state_dependent_inductance
}
MATERIAL_MODEL {
LINEAR_ISOTROPIC:
B = mu*H
GENERAL:
B = mu_0*(H + M)
CONSEQUENCE:
magnetic_flux depends_on material_response_through_B
RULE:
flux_calculation_in_materials SHOULD preserve permeability,
magnetisation, geometry_and_field_distribution_context
}
RELATIONSHIPS {
MagneticFlux -> SURFACE_INTEGRAL_OF -> MagneticFluxDensity
MagneticFlux -> HAS_DIMENSION -> M*L^2*T^-2*I^-1
MagneticFlux -> MEASURED_IN -> Weber
MagneticFluxDensity -> MEASURED_IN -> Tesla
MagneticFlux -> DEPENDS_ON -> SurfaceGeometry
MagneticFlux -> DEPENDS_ON -> SurfaceOrientation
TimeVaryingMagneticFlux -> INDUCES -> ElectromotiveForce
MagneticFluxLinkage -> SUMS -> FluxAcrossTurns
Inductance -> RELATES -> FluxLinkageAndCurrent
ClosedSurface -> HAS_ZERO_NET -> MagneticFlux
}
SEMANTIC_EQUIVALENCE {
"magnetic flux" ~= Phi_B
"weber" ~= "Wb"
"tesla square metre" ~= "T*m^2"
"volt second" ~= "V*s"
magnetic_flux != magnetic_flux_density
magnetic_flux != magnetic_field_strength
magnetic_flux != magnetic_flux_linkage
magnetic_flux != electromotive_force
weber != tesla
}
CONSTRAINTS {
magnetic_flux_is_scalar_surface_integral = true
magnetic_flux_has_orientation_dependent_sign = true
dimensional_formula = M*L^2*T^-2*I^-1
SI_unit = Wb
flux_requires_defined_surface = true
signed_flux_requires_surface_orientation = true
magnetic_flux_and_flux_density_are_not_semantically_equivalent = true
magnetic_flux_and_flux_linkage_are_not_generally_semantically_equivalent = true
net_flux_through_closed_surface_is_zero_in_standard_Maxwell_theory = true
}
MEASUREMENT_MODEL {
OBSERVABLE_OR_INFERRED:
MagneticFlux
COMMON_MEASUREMENT_METHODS:
fluxmeter
search_coil
integrating_voltage_measurement
Hall_probe_field_mapping_plus_surface_integration
calibrated_pickup_coil
INDIRECT_MEASUREMENT:
integrate_B_over_surface
integrate_induced_voltage_over_time
infer_from_flux_linkage_and_turn_count
infer_from_inductance_and_current_under_applicable_model
RECORD:
numerical_value
unit
surface_geometry
surface_area
surface_orientation
magnetic_flux_density_field
time
coil_turn_count_when_relevant
loop_orientation
material_or_core
instrument
calibration_state
integration_interval
uncertainty
UNCERTAINTY:
measured_or_inferred_flux = best_estimate +/- uncertainty
}
REASONING_RULES {
IF uniform_B_known AND planar_area_known AND angle_to_normal_known
THEN magnetic_flux = B*area*cos(angle)
IF B_field_known_over_surface
THEN magnetic_flux = surface_integral(B dot dA)
IF surface_orientation_reversed
THEN signed_magnetic_flux = -previous_signed_magnetic_flux
IF closed_surface
THEN net_magnetic_flux = 0
UNDER standard_classical_Maxwell_context
IF magnetic_flux_changes_with_time
THEN induced_emf = -derivative(magnetic_flux, time)
FOR single_loop_consistent_orientation
IF N_turns_known AND same_flux_links_each_turn
THEN magnetic_flux_linkage = N*magnetic_flux
IF flux_linkage_known_as_function_of_time
THEN induced_emf = -derivative(flux_linkage, time)
IF linear_inductance_known AND current_known
THEN flux_linkage = inductance*current
}
GEOMETRY_MODEL {
REQUIRE:
surface_definition
surface_area
surface_normal
field_distribution
nonplanar_surface:
local_normal_varies_over_surface
nonuniform_field:
B varies_over_surface
RULE:
B*A*cos(theta) shortcut
ONLY valid_for_uniform_B_and_planar_or_equivalent_constant_geometry
}
TIME_MODEL {
static_flux:
dPhi_B/dt = 0
time_varying_flux:
dPhi_B/dt != 0
induced_emf_context:
requires_flux_change_rate_and_orientation
RULE:
constant_nonzero_flux alone
DOES_NOT induce_emf_by_Faraday_flux_rule
}
UNCERTAINTY_MODEL {
sources:
magnetic_field_measurement_uncertainty
surface_area_uncertainty
orientation_uncertainty
spatial_sampling
integration_error
coil_turn_count
voltage_measurement_uncertainty
timing_uncertainty
calibration_uncertainty
material_and_geometry_model_uncertainty
PROPAGATION:
derived_flux_uncertainty
<- field_geometry_orientation_and_measurement_uncertainties
}
CONFIDENCE {
definition_confidence: 1.00
dimensional_confidence: 1.00
SI_unit_confidence: 1.00
surface_integral_relationship_confidence: 1.00
Faraday_relationship_confidence: 1.00
measurement_context_confidence: 0.98
RULE:
confidence decreases when surface geometry, orientation,
B-field distribution, time context, coil linkage,
material state, calibration or uncertainty is missing or ambiguous
}
VALIDATION {
CHECK dimensional_consistency
CHECK unit_consistency
CHECK surface_definition
CHECK surface_orientation
CHECK angle_is_relative_to_surface_normal
CHECK uniform_vs_nonuniform_field_assumption
CHECK open_vs_closed_surface
CHECK magnetic_flux_vs_flux_density_distinction
CHECK magnetic_flux_vs_flux_linkage_distinction
CHECK Faraday_orientation_and_sign_convention
CHECK turn_count_when_flux_linkage_used
CHECK instrument_calibration
CHECK uncertainty_representation_when_required
}
UPDATE_MODEL {
ON new_measurement:
validate_unit
identify_surface
identify_surface_orientation
identify_B_field_or_measurement_method
normalize_to_weber
preserve_original_value_and_unit
attach_time_or_interval
attach_coil_information_when_relevant
attach_uncertainty
update_flux_state
ON field_change:
update_B_field
recompute_surface_integral
update_flux
compute_flux_change_rate_when_required
infer_induced_emf_when_valid
ON geometry_or_orientation_change:
update_surface_geometry
update_surface_normal
recompute_flux
preserve_previous_geometry_state
ON coil_linkage_change:
update_turn_count_or_linkage
recompute_flux_linkage
update_inductance_relationship_when_valid
ON calibration_revision:
preserve_provenance
recompute_affected_measurements
update_confidence
ON semantic_revision:
preserve_previous_definition
record_revision
recompute_FLOW_HASH
}
AI_CONSUMPTION {
canonical_entity: MagneticFlux
canonical_symbol: Phi_B
canonical_dimension: M*L^2*T^-2*I^-1
canonical_SI_unit: Wb
interpretation_order:
identify_quantity
distinguish_flux_from_flux_density
identify_value
identify_unit
identify_surface_geometry
identify_surface_orientation
identify_B_field_distribution
identify_static_or_time_varying_context
identify_loop_or_coil_context
identify_turn_count_and_flux_linkage
identify_material_context
identify_measurement_method
identify_uncertainty
normalize_units
validate_dimensions
infer_induction_relationships
ambiguity_controls:
distinguish_magnetic_flux_from_magnetic_flux_density
distinguish_magnetic_flux_from_magnetic_field_strength
distinguish_flux_from_flux_linkage
distinguish_weber_from_tesla
distinguish_open_surface_flux_from_closed_surface_net_flux
distinguish_static_flux_from_flux_change
preserve_surface_orientation_and_Faraday_sign_convention
}
PROVENANCE {
ontology_scope:
mathematical_measurement_and_electromagnetic_quantity_semantics
parent_path:
Ontologies
-> Mathematical Ontologies
-> Measurement & Units Ontologies
-> Electromagnetic Measurements
-> Magnetic Flux Ontology
authorship:
Mark Higgins
Sky (Recursive AI)
site:
https://kirethresearch.org
}
FLOW_HASH {
INPUTS:
canonical_entity
ontology_path
definitions
dimensions
units
relationships
constraints
surface_integral_model
orientation_model
Gauss_magnetism_model
Faraday_induction_model
flux_linkage_model
inductance_model
material_model
geometry_model
time_model
uncertainty_model
reasoning_rules
measurement_model
confidence_model
update_model
PURPOSE:
deterministic_semantic_integrity_identifier
RECOMPUTE_WHEN:
ontology_definition_changes
relationship_model_changes
surface_or_orientation_model_changes
induction_model_changes
flux_linkage_model_changes
material_model_changes
measurement_model_changes
constraint_model_changes
reasoning_rule_changes
unit_model_changes
}
}
END FLOW
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