The ratio of static pressure () to freestream pressure () with perturbations, often denoted as , is a dimensionless parameter used in fluid dynamics and aerodynamics to describe the pressure variation at a specific point in a fluid flow that includes perturbations or disturbances.
- Ratio of static to the freestream pressure (p/p∞)
- Specific heat ratio (γ)
- Freestream Mach number (M∞)
- Horizontal Perturbation Velocity (û) in m/s
- Freestream velocity (V∞) in m/s
- Vertical Perturbation Velocity (v̂) in m/s