1. Velocity Head (h)

The velocity head is the height of a column of fluid that corresponds to the kinetic energy of the fluid.

The formula for calculating the velocity head is:

ℎ = v² / 2g

Where:

• ℎ = Velocity head (in meters, m)
• v = Velocity of the gas (in meters per second, m/s)
• g = Acceleration due to gravity (approximately 9.81 m/s²)

To calculate the velocity head, you square the velocity of the gas, divide by two, and then divide by the acceleration due to gravity.

2. Velocity of Flow Gas of Stack (v)

The velocity of flow gas in a stack can be determined using the velocity head.

The formula for calculating the velocity of flow gas is:

v = √(2gh)

Where:

• v = Velocity of the flow gas (in meters per second, m/s)
• g = Acceleration due to gravity (approximately 9.81 m/s²)
• h = Velocity head (in meters, m)

To calculate the velocity of the flow gas, multiply the velocity head by two and the acceleration due to gravity, then take the square root of the result.