Knudsen number

{
  "id": "MLC-T-MET-006799",
  "term": "Knudsen number",
  "field": "Meteorology and atmospheric science",
  "definition": "A dimensionless quantity that compares the molecular mean free path of a fluid to a representative physical length scale of a system. This ratio determines whether a fluid can be modeled as a continuous medium or as a collection of discrete particles. A low Knudsen number (less than 0.01) indicates that continuum mechanics is applicable, while a high number suggests that statistical mechanics must be used.",
  "url": "https://mlchart.com/terminology/meteorology/knudsen-number/"
}