Model Perspective

Jan 25, 2026 · Fundamentals

Why High‑Speed Trains Make You Drowsy: A Fluid‑Dynamics Model of CO₂ Build‑Up

A recent video showing CO₂ levels rising from 880 ppm to over 2000 ppm inside a high‑speed train cabin sparked analysis that uses fluid‑mechanics and mass‑conservation modeling to explain why passengers often feel sleepy, comparing standards, physiological impacts, and ventilation efficiency.