Enter the flow rate, viscosity, capillary length, and capillary radius into the calculator to determine the back pressure.
Capillary Back Pressure Formula
The following formula is used to calculate the back pressure in a capillary for a given flow rate, viscosity, length, and radius.
ΔP = (8 * η * L * Q) / (π * r^4)
Variables:
- ΔP is the back pressure
- η is the viscosity
- L is the capillary length
- Q is the flow rate
- r is the capillary radius
To calculate the back pressure, multiply the viscosity by the length and the flow rate, then multiply by 8. Divide the result by π times the radius to the power of 4.
What is Capillary Back Pressure?
Capillary back pressure is the pressure required to drive a fluid through a capillary tube. This pressure is influenced by factors such as the fluid’s viscosity, the length and radius of the capillary, and the flow rate of the fluid. Understanding and calculating capillary back pressure is essential in various scientific and industrial applications, including chromatography, microfluidics, and medical diagnostics.
How to Calculate Capillary Back Pressure?
The following steps outline how to calculate the Capillary Back Pressure.
- First, determine the flow rate (Q).
- Next, determine the viscosity (η).
- Next, determine the capillary length (L).
- Next, determine the capillary radius (r).
- Finally, calculate the Capillary Back Pressure using the formula ΔP = (8 * η * L * Q) / (π * r^4).
- After inserting the values and calculating the result, check your answer with the calculator above.
Example Problem :
Use the following variables as an example problem to test your knowledge.
Flow Rate (Q) = 0.5 m³/s
Viscosity (η) = 0.001 Pa·s
Capillary Length (L) = 2 m
Capillary Radius (r) = 0.01 m