Part 11: Characteristic Numbers·115 entries

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11-8.4

Alfvén number, Mach magnetic number, Kárman number

URNurn:iso:std:iso:80000:-11:ed-2:en:item:11-8.4

https://metanorma.github.io/isq-smart/quantities/part-11/t11-8.4
urn:iso:std:iso:80000:-11:ed-2:en:item:11-8.4

ISQ Identifiers

ISO

urn:iso:std:iso:80000:-11:ed-2:en:item:11-8.4

IEC

urn:iec:std:iec:80000-11:2019:::item:11-8.4

Designations

ENAlfvén number

FRnombre d'Alfvén

ENMach magnetic number

FRnombre de Mach magnétique

ENKárman number

FRnombre de Kárman

Symbol

A l

Notation systems

Rendered

A l

AsciiMath

Al

LaTeX

A l

Definition

relation between speed of a plasma and the Alfvén wave speed, expressed by

$A l = \frac{v}{B / \sqrt{ρ μ}}$ ; where

$v$ :: is speed (ISO 80000-3: Space and time),

$B$ :: is magnetic flux density (IEC 80000-6: Electromagnetism),

$ρ$ :: is mass density (ISO 80000-4: Mechanics), and

$μ$ :: is magnetic permeability (IEC 80000-6: Electromagnetism)

relation entre la vitesse d'un plasma et la vitesse des ondes d'Alfvén, exprimée par

$A l = \frac{v}{B / \sqrt{ρ μ}}$ ; où

$v$ :: est la vitesse (ISO 80000-3: Space and time),

$B$ :: est l'induction magnétique (IEC 80000-6: Electromagnetism),

$ρ$ :: est la masse volumique (ISO 80000-4: Mechanics), et

$μ$ :: est la perméabilité magnétique (IEC 80000-6: Electromagnetism)

Notes

Often, the inverse of this number is wrongly used.

The name "Alfvén Mach number" is used in investigations on the solar wind.

The quantity $v_{A} = B / \sqrt{ρ μ}$ is called Alfvén wave speed, where

$B$ :: is magnetic flux density (IEC 80000-6: Electromagnetism),

$ρ$ :: is mass density (ISO 80000-4: Mechanics), and

$μ$ :: is magnetic permeability (IEC 80000-6: Electromagnetism).

Parfois, l'inverse de ce nombre est utilisé à tort.

Le nom «nombre d'Alfvén-Mach» est utilisé dans les études relatives au vent solaire.

La grandeur $v_{A} = B / \sqrt{ρ μ}$ est appelée vitesse des ondes d'Alfvén, où

$B$ :: est l'induction magnétique (IEC 80000-6: Electromagnetism),

$ρ$ :: est la masse volumique (ISO 80000-4: Mechanics), et

$μ$ :: est la perméabilité magnétique (IEC 80000-6: Electromagnetism).

Referenced by

Lundquist number Naze number

Concept HierarchyPendrill (2024)

1dimensionless quantitiesLevel 0 · Kind

Broader concepts

◇ dimensionless quantities

Characterizes

● wave

Ontology
isq:Quantity smart:TermEntry

Class Hierarchy

smart:Entity smart:TermEntryisq:Quantity

A physical quantity as defined in ISO/IEC 80000, with associated symbols, definitions, and units of measurement.

Instance IRI

isq:t11-8.4

Properties

isq:QuantityShape

Property	Value
rdf:type	isq:Quantity smart:TermEntry
dcterms:identifier	11-8.4
skosxl:prefLabel	"Alfvén number"@en
skosxl:altLabel	"Mach magnetic number"@en"Kárman number"@en"Al"@en
skos:definition	relation between speed of a plasma and the Alfvén wave speed, expressed by stem:[Al = v/(B//sqrt(rho mu))]; where stem…
skos:note	Often, the inverse of this number is wrongly used. The name "Alfvén Mach number" is used in investigations on the solar…
isq:hasDimension	isq:Dimension
smart:hasBindingnessType	bindingness-type:normative
dcterms:isPartOf	isq:part-11

Related Entities

isq:QuantityShape isq:part-11 isq:Unit isq:Dimension isq:hasDimension smart:TermEntry