`@ferret/physics-heat`

temperature of parts, conduction, convection, radiation, phase change, expansion and melting.

23 exports · source in packages/physics-heat/src

Classes

HeatNetwork class

class HeatNetwork

Lumped parts joined by conductances, with convection and radiation to the surroundings. Stepped by Crank-Nicolson (second order, stable at any step); the state is the enthalpy, so a phase change holds the temperature while latent heat is paid and the energy balance closes exactly. Order is fixed (insertion), so a replay gives the same temperatures.

`readonly parts: Part[]`
`readonly links: Link[]`
`ambient: number`
`onEvent: ((e: HeatEvent) => void) \| null`	called for phase changes and passed limits
`boundary: number`	heat that crossed the boundary (surroundings, fixed parts), J: lets a test check the balance
`addPart(d: PartDef): Part`
`removePart(p: Part)`
`join(a: Part, b: Part, G: number): Link`
`unjoin(l: Link)`
`part(name: string): Part \| undefined`
`add(p: Part, joules: number)`	Put heat into a part now (J).
`setTemperature(p: Part, T: number)`
`stored(): number`	Thermal energy stored in all free parts, J.
`ambientOf(p: Part)`
`stress(p: Part): number`	Thermal stress in a held bar (Pa, negative = compression) and the free growth of a bar.
`strength(p: Part): number`
`grown(p: Part): number`
`step(dt: number)`
`grid(o: { name: string; material: HeatMaterial; nx: number; ny?: number; dx: number; dy?: number; thickness: number; T?: number; edge?: { left?: number; right?: number } }): Part[][]`	A bar, a slab or a plate as a grid of parts (cells), joined along the faces: `ny` = 1 makes a rod. The cell at (0, j) can be held at a temperature with `edge`. Returns the cells by [j][i].

packages/physics-heat/src/network.ts:108

Functions

enthalpy function

function enthalpy(m: HeatMaterial, mass: number, T: number): number

packages/physics-heat/src/network.ts:77

erfc function

function erfc(x: number): number

Complementary error function (Abramowitz-Stegun 7.1.26, error under 1.5e-7).

packages/physics-heat/src/material.ts:91

expansion function

function expansion: (m: HeatMaterial, length: number, dT: number) => number

Free thermal growth of a bar: dL = alpha·L·dT.

packages/physics-heat/src/material.ts:74

heat function

function heat(o: { network?: HeatNetwork; materials?: HeatLibrary } = {}): HeatCapability

packages/physics-heat/src/index.ts:40

strengthFactor function

function strengthFactor(m: HeatMaterial, T: number): number

Strength factor 0..1 of a material at a temperature, from its curve (linear between points, flat beyond).

packages/physics-heat/src/material.ts:65

temperatureOf function

function temperatureOf(m: HeatMaterial, mass: number, H: number): { T: number; phase: Phase; cap: number }

Temperature and phase for an enthalpy: the plateaus hold the melting and boiling points.

packages/physics-heat/src/network.ts:86

thermalStress function

function thermalStress: (m: HeatMaterial, dT: number) => number

Stress in a bar held at both ends: sigma = E·alpha·dT (compression when heated).

packages/physics-heat/src/material.ts:76

wallConductance function

function wallConductance(layers: Array<{ thickness: number; k: number }>, area: number): number

Conductance of a wall of layers in series, W/K: A / sum(L_i / k_i).

packages/physics-heat/src/material.ts:79

Interfaces

AttachDef interface

interface AttachDef extends Omit<PartDef, 'material' | 'name'>

`material: string`
`name?: string`

packages/physics-heat/src/index.ts:24

HeatCapability interface

interface HeatCapability extends Capability

`readonly network: HeatNetwork`
`readonly materials: HeatLibrary`
`attach(entity: Entity, def: AttachDef): Part`	Give a body's entity a temperature.
`partOf(entity: Entity): Part \| undefined`

packages/physics-heat/src/index.ts:26

HeatMaterial interface

interface HeatMaterial

A material's thermal record: the same data for a rod, a wall, a block of ice and a brake disc.

`density: number`	kg/m³
`c: number`	specific heat of the solid, J/(kg·K)
`k: number`	thermal conductivity, W/(m·K)
`emissivity?: number`	surface emissivity, 0..1
`melt?: { T: number; latent: number; c: number }`	melting and boiling: the temperature (K), the latent heat (J/kg) and the specific heat of what comes after
`boil?: { T: number; latent: number; c: number }`
`alpha?: number`	linear thermal expansion, 1/K, and Young's modulus, Pa
`E?: number`
`sigmaMax?: number`	stress (Pa) the material holds at room temperature, and its fall with temperature as [K, factor] points
`strengthCurve?: Array<[number, number]>`
`ignition?: number`	ignition temperature, K

packages/physics-heat/src/material.ts:2

Link interface

interface Link

`a: Part`
`b: Part`
`G: number`
`id: number`

packages/physics-heat/src/network.ts:62

Part interface

interface Part

`readonly id: number`
`readonly name: string`
`readonly mass: number`
`readonly material: HeatMaterial`
`T: number`
`H: number`	enthalpy, J, from 0 K as a solid
`area: number`
`h: number`
`radiates: boolean`
`fixed: boolean`
`ambient?: number`
`power: number`
`length: number`
`held: boolean`
`reference: number`
`limit?: number`
`limitHit: boolean`
`userData?: unknown`
`entity?: string`	the entity this part belongs to (a vessel standing in it takes its thresholds from that entity's scope)
`phase: Phase`
`flowed: number`	energy that has flowed into the part from its links and surroundings, J (negative = out)

packages/physics-heat/src/network.ts:35

PartDef interface

interface PartDef

`name: string`
`mass?: number`	kg; or give `volume` and the density of the material is used
`volume?: number`
`material: HeatMaterial`
`T?: number`	starting temperature, K
`area?: number`	area exposed to the surroundings, m²
`h?: number`	convection coefficient to the surroundings, W/(m²·K); 0 = none
`radiates?: boolean`	emissivity; the material's when missing (and radiation is only counted when `radiates` is true)
`fixed?: boolean`	held at its temperature (a heat bath, a wall face at a given temperature)
`ambient?: number`	surroundings of this part, K; the network's ambient when missing
`power?: number`	continuous heating, W
`length?: number`	length (m) and whether both ends are held: a bar that cannot grow carries a thermal stress
`held?: boolean`
`reference?: number`	installed (stress-free) temperature, K
`limit?: number`	a limit of temperature (K) that raises `over` once
`userData?: unknown`

packages/physics-heat/src/network.ts:5

Types

HeatEvent type

type HeatEvent = | { kind: 'phase'; part: Part; to: Phase; from: Phase } | { kind: 'over'; part: Part; limit: 'temperature' | 'stress'; value: number }

packages/physics-heat/src/network.ts:64

Phase type

type Phase = 'solid' | 'melting' | 'liquid' | 'boiling' | 'gas'

packages/physics-heat/src/network.ts:3

Constants

EXAMPLE_CONVECTION const

const EXAMPLE_CONVECTION: Record<string, (v: number) => number>

Convection coefficient, W/(m²·K), of a medium at a flow speed: still values plus a velocity term (McAdams-type, as data).

packages/physics-heat/src/material.ts:84

EXAMPLE_HEAT_MATERIALS const

const EXAMPLE_HEAT_MATERIALS: Record<string, HeatMaterial>

packages/physics-heat/src/material.ts:24

HEAT_DEFAULTS const

const HEAT_DEFAULTS: { ambient: number; frictionToHeat: number; contactConductance: number; }

temperature. Every part (a body, a wall, a gas, a reservoir) has a temperature; heat moves by conduction between parts, by convection and radiation to the surroundings, and a phase change holds the temperature while its latent heat is paid. Work lost in contacts (friction, rolling, inelastic hits) becomes heat in the parts that touched, so the energy balance closes.

values (each at world / level / zone / entity scope):

  ambient              temperature of the surroundings, K                                   (293.15)
  frictionToHeat       share of the mechanical energy lost in a contact that becomes heat    (1)
  contactConductance   W/K between two parts that touch; 0 = no conduction at contacts       (0)

events: heat:phase { part, to, from }, heat:over { part, limit, value }, heat:ignite { part }.

packages/physics-heat/src/index.ts:22

SIGMA const

const SIGMA: 5.670374419e-8

packages/physics-heat/src/material.ts:61

T_ROOM const

const T_ROOM: 293.15

packages/physics-heat/src/material.ts:62

`constructor(initial: Record<string, HeatMaterial> = EXAMPLE_HEAT_MATERIALS)`
`add(name: string, m: HeatMaterial)`
`get(name: string): HeatMaterial`
`has(name: string)`
`names()`

@ferret/physics-heat