Physics / Engineering
Four-stroke engine
Slider-crank, an Otto cycle with a finite burn, and a shaft the gas turns.
What happens
Explore a four-stroke engine with slider-crank geometry, finite-duration combustion and a shaft accelerated by gas torque against inertia, drag and load. Compare the pressure-volume cycle, gas torque and brake power. Brake power is the output delivered to the external load. The ideal Otto efficiency is a reference for instantaneous heat addition; this is a simplified engine model, not a combustion or emissions solver. Switch off ignition to let it coast to rest.
Equations used in the module
Equations Otto: η = 1 − 1/r^(γ−1) pV^γ = const W = ∮p dV p_mean = W/(V_max−V_min) I dω/dt = τ_gas − τ_drag − τ_load P_load = τ_load ω
