viscosity
Let an agent define viscosity and its kinds, relay values, units and measurement methods from reference sources, explain Newtonian and non-Newtonian behaviour, and describe applications across fields.
Research draft, second pass
A second pass drafted this model: the structure a model of this thing needs, and what is known about it in the world. The line under this one says how the second half was obtained - researched against sources, or recalled without web access, in which case nothing here was read anywhere and every claim is a lead to verify. Unreviewed either way.
written by Claude from model knowledge without web access - no source was read, every claim is a lead to verify
Researched by: Claude
Purpose and description
Let an agent define viscosity and its kinds, relay values, units and measurement methods from reference sources, explain Newtonian and non-Newtonian behaviour, and describe applications across fields.
A measure of a fluid resistance to flow or deformation, expressed as dynamic viscosity in pascal-seconds or poise and as kinematic viscosity, the ratio of dynamic viscosity to density, in square metres per second or stokes, with extensions such as extensional viscosity for stretching flows and time-dependent viscosity in thixotropic and rheopectic fluids; viscosity depends strongly on temperature, distinguishes Newtonian from non-Newtonian fluids, and matters in lubrication, food, blood flow, polymers and geology.
What it is for: Characterising resistance to flow.
It can be define and explain kinds; relay values and units; explain measurement; describe applications.
Distinguishing features
Shear stress to strain rate ratio
Temperature dependence
Newtonian and non-Newtonian
Many measurement methods
What it looks like
Not a visible object; seen as how slowly a liquid pours.
Physical character
water dynamic viscosity at 20 C: about 1.0 mPa s
honey dynamic viscosity: about 2000-10000 mPa s - varies
air dynamic viscosity at 20 C: about 0.018 mPa s
How it is recognised
Resistance of a fluid to flow
Dynamic, kinematic, extensional and time-dependent viscosity
Density is mass per volume; surface tension is a different property
Related models
is a kind of - in registry terms
is a kind of - in registry terms, loosely
is studied by - the field
is measured by - and rheometers
In practice
Families and kinds
dynamic viscosity
kinematic viscosity
viscosity of solutions and solvents, including intrinsic viscosity
extensional viscosity
time-dependent viscosity in thixotropic and rheopectic fluids
apparent viscosity of non-Newtonian fluids
Identifiers
SI unit Pa s dynamic
SI unit m2/s kinematic
Standards and regulation
ISO and ASTM viscosity measurement standards
SAE and ISO viscosity grades for lubricants
Pharmacopoeial viscosity tests
Failure modes and hazards
Unit confusion between dynamic and kinematic
Ignoring temperature dependence
Applying Newtonian assumptions to non-Newtonian fluids
Also called
Where this came from
wikidata · CC0 1.0
Drafted structure
Bundle to layer to finding to question, as the second pass will find it: 4 bundles · 8 layers · 8 findings · 16 questions.
Define Definition and kinds.
Science.
Definition
Definition.
Definition
Definition.
- What is viscosity, and how do dynamic and kinematic viscosity differ? definition
- Is the question about viscosity or another fluid property? boundary
Behaviour
Newtonian and non-Newtonian.
Behaviour
Behaviour.
- How do Newtonian, shear-thinning, shear-thickening and time-dependent fluids differ? definition
- Which entry fits the specific behaviour? action
Measure Measurement and values.
Metrology.
Methods
Methods.
Methods
Methods.
- How is viscosity measured with capillary, rotational, falling ball and other viscometers? provenance
- Which references are standard? provenance
Values
Values and units.
Values
Values.
- What are typical viscosities of common fluids, and how are units converted? measurement
- Which entry fits unit conversion? action
Science Physics and theory.
Science.
Physics
Molecular origin.
Physics
Physics.
- What is the molecular origin of viscosity in gases and liquids, and why does temperature matter? provenance
- Which sources are cited? provenance
Flow
Role in fluid dynamics.
Flow
Flow.
- How does viscosity enter the Navier-Stokes equations and the Reynolds number? provenance
- Which entry fits fluid dynamics? action
Apply Applications.
Application.
Engineering
Engineering.
Engineering
Engineering.
- How does viscosity matter in lubrication, pipelines, polymers and food processing? provenance
- Which entry fits the specific application? action
Nature
Nature and body.
Nature
Nature.
- How does viscosity matter in blood flow, magma and the Earth mantle? provenance
- Which entry fits the specific field? action
What the second pass must settle
- Should kinematic viscosity be a separate entry?
- How should reference tables be linked?
- The registry entry has merged aliases naming kinds and contexts; should they be split off?