Physics2D / computed foundations

A tiny opening changes the whole chamber.

Compare a sealed chamber, a permanent vent and a delayed breach. Connectivity answers whether gas can escape; a separate pressure model answers how fast it does.

Vent width · cellsOpening timeHeat input · model unitsTimeline

Outside reachability is computed by a four-neighbor flood fill. Any open path removes the binary sealed label; vent width still controls conductance. Pressure follows a separate uniform-chamber ideal-gas calculation with the same heat input in both curves. Moving dots indicate the possible route, not computed gas trajectories.

—Trapped air cells

—Pressure / ambient

—Temperature / ambient

Equations and model boundary

pV = mRT;  U = m cᵥT
ṁ = −q;  U̇ = Q − Qcool − q cₚTupstream
q = conductance × (p − pamb)

Dimensionless, fixed-volume ideal gas: R=1, γ=1.4, initial p=T=m=V=1. Heat is supplied until t=3. Signed q permits ambient inflow; upstream temperature is the chamber temperature for outflow and ambient temperature for inflow. The opening time is prescribed; no fracture, spatial jet, combustion or shock is simulated. The native sandbox instead couples cellwise pressure surrogates, reachability masks and authored vent responses. This experiment explains why topology, release rate and energy accounting are distinct requirements; it is not a native pressure validation.