Shear stress (τ) is a fundamental concept in mechanics and fluid dynamics that quantifies the force per unit area acting parallel to the surface of a material or fluid element. It describes the internal resistance of a material to deform when subjected to tangential or shearing forces.
- τ: Shear stress in the fluid in N/m²
- μ: Dynamic viscosity of the fluid in kg/m·s
- ue: Average velocity of the fluid at the boundary in m/s
- D: Distance in m