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Research draft

fluid

vr.tr.fluid · PHY.MAT

Let an agent explain fluids, relay properties, classifications and governing equations from physics and engineering sources, and distinguish fluids from solids, liquids alone, bodily fluids as a biological category and the colloquial sense of fluid as flexible.

Thing Registry Physical world and living systems

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 explain fluids, relay properties, classifications and governing equations from physics and engineering sources, and distinguish fluids from solids, liquids alone, bodily fluids as a biological category and the colloquial sense of fluid as flexible.

A substance that continuously deforms, or flows, under an applied shear stress, including liquids, gases and plasmas, characterised by properties such as density, pressure and viscosity, and classified as Newtonian fluids, such as water and air, whose viscosity is independent of shear rate, or non-Newtonian fluids, such as blood, ketchup and cornstarch suspensions; fluids are studied in fluid mechanics, and supercritical fluids combine properties of liquids and gases.

What it is for: Not applicable; a state-based category of matter.

It can be explain properties; relay classifications; describe governing equations; distinguish related concepts.

Distinguishing features

Flows under shear

No fixed shape

Viscosity

Continuum description

What it looks like

Liquids that take the shape of their container, gases that fill it, and flowing materials.

Physical character

water dynamic viscosity at 20 C: about 1.0 mPa s

air density at sea level: about 1.225 kg/m3 - 15 C

governing equations: Navier-Stokes equations note

How it is recognised

Substance that flows under shear stress

Fluid, liquid, gas, plasma, supercritical fluid

Solids resist shear elastically; liquids are one kind of fluid; bodily fluids are biological; fluid also means flexible colloquially

Related models

is a kind of - in registry terms

continuum

is studied in -

fluid mechanics

includes -

liquid

is contrasted with -

solid

In practice

Families and kinds

liquids

gases

plasmas

Newtonian fluids

non-Newtonian fluids

supercritical fluids

superfluids

Standards and regulation

ISO viscosity measurement standards

Hydraulic fluid specifications

Failure modes and hazards

Confusing liquids and fluids

Misapplying Newtonian models to complex fluids

Ambiguity with bodily fluids

Where this came from

wikidata · CC0 1.0

Also registered as vr.tr.fluid-substance

Drafted structure

Bundle to layer to finding to question, as the second pass will find it: 4 bundles · 8 layers · 8 findings · 16 questions.

Understand What a fluid is.

Science.

Definition

Definition.

Definition

Definition.

  1. What is a fluid, and how does it differ from solids, liquids alone, bodily fluids and the everyday sense of fluid? definition
  2. Is the question about physics, engineering, cooking or biology? boundary

Kinds

Kinds.

Kinds

Kinds.

  1. How do liquids, gases, plasmas and supercritical fluids differ? definition
  2. Which entry fits the specific kind? action
Properties Properties.

Science.

Viscosity

Viscosity.

Viscosity

Viscosity.

  1. What is viscosity, and how do Newtonian and non-Newtonian fluids differ? provenance
  2. Which references are standard? provenance

Pressure

Pressure and buoyancy.

Pressure

Pressure.

  1. How do pressure, Pascal s principle and buoyancy work in fluids? provenance
  2. Which sources are cited? provenance
Mechanics Fluid mechanics.

Application.

Equations

Governing equations.

Equations

Equations.

  1. What do the Navier-Stokes and Euler equations describe? provenance
  2. Which entry fits Navier-Stokes equations? action

Flow

Laminar and turbulent flow.

Flow

Flow.

  1. How does the Reynolds number predict turbulence? provenance
  2. Which entry fits Reynolds number? action
Context Everyday and exotic fluids.

Context.

Everyday

Non-Newtonian examples.

Everyday

Everyday.

  1. Why do ketchup and cornstarch mixtures behave strangely? provenance
  2. Which entry fits non-Newtonian fluid? action

Superfluids

Superfluids.

Superfluids

Superfluids.

  1. What is superfluid helium? provenance
  2. Which entry fits superfluidity? action

What the second pass must settle

  • Should non-Newtonian fluid be a separate entry?
  • How should fluid mechanics sources be linked?
  • Should the everyday sense be disambiguated?