Ratio of static pressure to freestream pressure Calculator

The ratio of static pressure ($p$) to freestream pressure (p∞​) with perturbations, often denoted as p/p∞​, 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. Static pressure represents the pressure at a specific point in a fluid flow. It is the pressure measured when the fluid is at rest or moving at the same velocity. Freestream pressure refers to the pressure of the fluid in the undisturbed, far-field region or the approaching flow before any interactions with objects or disturbances occur. 

• p/p∞​ is the ratio of static pressure to freestream pressure, which describes how the local static pressure compares to the freestream pressure (dimensionless)
• $ϵ$ (epsilon) is a parameter that likely represents the ratio of the change in total pressure to freestream total pressure, often associated with a specific type of flow or phenomenon (dimensionless)
• $\gamma$  is the specific heat ratio (also known as the adiabatic index or ratio of specific heats) of the fluid (dimensionless)