Physics
What @aeronautic/countermeasures/physics exports.
Everything the flares and chaff are worked out from, for a tool, a test or a HUD.
The grain
| export | what it is |
|---|---|
FLARE | The flares by name: mju7. |
MTV_FRACTIONS, MTV_DENSITIES | MTV1's composition by mass, and its ingredients' densities. |
mixture_density(fractions, densities) | A mixture's theoretical density. |
grain_length(flare), burn_time(flare) | The grain's length, and how long it burns. |
grain_at(flare, age) | Its sides, mass and burning surface after burning a while. |
mass_rate(flare, grain) | What it burns a second, kg/s. |
flare_at_pressure(flare, p) | The flare burning at a pressure: its rate as MTV's goes. |
SEA_LEVEL_PA, SEA_LEVEL_DENSITY | Sea level's pressure and density, which the rates are at. |
The flame
| export | what it is |
|---|---|
band_intensity(flare, grain) | Its intensity in its band, W/sr. |
luminous_per_band(flare) | The candela each W/sr of the band brings, at the flame's temperature. |
flare_light(flare, grain, …, v, ρ) | Its luminous intensity, cd, its trail's, and its flame's radius. |
airstream_share(flare, v, ρ) | The share of its light the airstream leaves at the grain. |
trail_colors(flare, rgb, f, n) | Its trail's colours as it cools, over f e-folds of its light. |
planck(λ, T), band_radiance(a, b, T) | A blackbody's spectral radiance, and its radiance over a band. |
blackbody_luminance(T), PHOTOPIC, KM | Its luminance, cd/m², from the CIE photopic curve and 683 lm/W. |
The flight
| export | what it is |
|---|---|
mean_area(grain) | A tumbling grain's mean projected area: a quarter its surface. |
drag_per_speed2(flare, grain, ρ) | Its drag deceleration over its speed squared, 1/m. |
terminal_speed(flare, ρ) | How fast it falls once slowed, m/s. |
G0 | Standard gravity. |
The smoke
| export | what it is |
|---|---|
smoke_sigma(σ₀, ε, t) | How wide the smoke has spread, Richardson's law. |
henyey_greenstein(cos θ, g) | The phase function it scatters with, per steradian. |
The chaff
| export | what it is |
|---|---|
CHAFF | The chaff by name: rr178. |
chaff_mass(chaff) | The payload's mass, kg. |
dipole_count(chaff) | How many dipoles it holds, of the typical cut. |
chaff_cross_section(chaff) | The light they all stop, π d L / 4, m². |
air_viscosity(T) | The air's dynamic viscosity, Sutherland's law, Pa·s. |
chaff_fall_speed(chaff, T, ρ) | How fast a dipole falls broadside: Lamb's drag in Oseen's flow. |
dipole_tumble_rate(chaff, ε) | How fast the air's eddies turn a dipole, rad/s. |
glint_share(α, |s + v|, sweep, D) | The share of its dipoles that glint to the eye over a frame. |
SUN_RADIUS_RAD | The sun's angular radius. |
dipole_tilt(chaff, U, T, ρ, ε) | How far from level a falling dipole lies, radians. |
mirror_density(level, σ, h_y) | The share of the cloud's mirror facing h. |
level_shadow(level, v_y) | How much more of a level fibre shows from v than turned every way. |
chaff_bloom(chaff, age) | How far the cloud has bloomed, 0 to 1. |
The programs
| export | what it is |
|---|---|
default_program() | Two flares, four times. |
program_releases(program, dispensers) | Each release's time from the press, and where. |
The glare, the haze and the exposure are core's: glare_psf, extinction,
transmission, exposure_ev100 and the rest, from @aeronautic/core.