laminar flow

Laminar flow provides smooth, unidirectional airflow in cleanrooms, preventing particle turbulence and contamination. **Definition**: Fluid moves in parallel layers with no disruption between them. As opposed to turbulent flow with chaotic mixing. **In cleanrooms**: Air flows uniformly from ceiling to floor (vertical) or wall to wall (horizontal). Particles carried away from work surfaces. **Velocity**: Typically 0.3-0.5 m/s (60-100 fpm). Fast enough to move particles, slow enough to not disturb processes. **Creating laminar flow**: FFUs (Fan Filter Units) across ceiling provide uniform filtered air. Perforated floor panels allow air return. **Benefits**: Contaminants swept away, doesnt recirculate particles, predictable particle trajectories, effective contamination control. **Disruptions**: Equipment, people, movements create turbulence locally. Minimize disruption through design and protocols. **Measurement**: Smoke testing visualizes airflow patterns. Anemometers measure velocity and uniformity. **Design considerations**: Avoid obstacles that create turbulence, locate particle sources away from critical work, maintain proper velocity. **Applications**: Semiconductor wafer processing, pharmaceutical manufacturing, surgical suites.