Enter the static pressure (Pa), the fluid density (kg/m^3), and the fluid speed (m/s) into the calculator to determine the Stagnation Pressure. 

Stagnation Pressure Formula

The following formula is used to calculate the Stagnation Pressure.

Pstag = Pstatic + 1/2 * p * v^2
  • Where Pstag is the Stagnation Pressure (Pa)
  • Pstatic is the static pressure (Pa) 
  • p is the fluid density (kg/m^3) 
  • v is the fluid speed (m/s) 

To calculate the stagnation pressure, multiply the density by the velocity squared, divide by 2, then add the static pressure to the result.

How to Calculate Stagnation Pressure?

The following example problems outline how to calculate the Stagnation Pressure.

Example Problem #1

  1. First, determine the static pressure (Pa). In this example, the static pressure (Pa) is given as 10 .
  2. Next, determine the fluid density (kg/m^3). For this problem, the fluid density (kg/m^3) is given as  1250 .
  3. Next, determine the fluid speed (m/s). In this case, the fluid speed (m/s) is found to be 5.
  4. Finally, calculate the Stagnation Pressure using the formula above: 

Pstag = Pstatic + 1/2 * p * v^2

Inserting the values from above and solving yields: 

Pstag = 10 + 1/2 * 1250 * 5^2 = 15635 (Pa)


FAQ

What is the significance of calculating Stagnation Pressure in fluid dynamics?

Stagnation pressure is crucial in fluid dynamics as it represents the total pressure a fluid attains when it is brought to a stop isentropically from a given velocity. This measure is essential for understanding the energy characteristics of a fluid flow, including its potential to perform work when decelerated. It is widely used in the design and analysis of wind tunnels, jet engines, and various aerodynamic components to ensure optimal performance and safety.

How does fluid density affect the Stagnation Pressure?

Fluid density directly influences the stagnation pressure. According to the stagnation pressure formula (P_{stag} = P_{static} + frac{1}{2} rho v^2), an increase in fluid density ((rho)) leads to a higher dynamic pressure component ((frac{1}{2} rho v^2)), thereby increasing the total stagnation pressure. This relationship highlights the importance of fluid density in determining the energy characteristics of a fluid flow, especially in high-speed applications such as aerospace and turbo machinery.

Can Stagnation Pressure be less than the static pressure?

No, stagnation pressure cannot be less than the static pressure. By definition, stagnation pressure is the sum of the static pressure and the dynamic pressure (which is always positive or zero). The dynamic pressure represents the kinetic energy per unit volume of the fluid flow, which adds to the static pressure when the fluid is brought to a stop isentropically. Therefore, the stagnation pressure is always equal to or greater than the static pressure.