Pressure Drop Formula, Definition, Solved Examples

Pressure Drop Formula: Pressure drop is the variance in pressure observed between two locations within a fluid-carrying network. This phenomenon arises due to the frictional force generated by the resistance encountered by the fluid as it traverses through the tubing.

The relationship between viscosity and the speed of the liquid plays a crucial role in pressure drop. The primary determinants of resistance to liquid flow are the velocity of the fluid within the pipe and its viscosity. The pressure drop is directly proportional to the frictional shear forces experienced within the network of pipes.

The pressure drop, denoted as J, is calculated using the following formula:

J= f⋅ L⋅v ² ​/ 2⋅g⋅D

Where:  J represents the pressure drop,  f is the friction factor,  L is the length of the tube,  v is the velocity of the fluid,  g is the acceleration due to gravity, and  D is the inner diameter of the tube.

Pressure Drop Formula Solved Examples

Example 1: A fluid is flowing through a tube with a friction factor (  f) of 0.35. The tube has a length (  L) of 12 meters, an inner diameter (  D) of 0.08 meters, and the fluid velocity (  v) is 25 m/s. Calculate the pressure drop (  J) using the given parameters.

Example 2: Question: A liquid is flowing through a pipe with a friction factor (f) of 0.25. The pipe has a length ( L) of 18 meters, an inner diameter ( D) of 0.12 meters, and the liquid velocity ( v) is 35 m/s. Calculate the pressure drop (  J) using the given parameters.

Example 3: Water is flowing through a pipeline with a friction factor (  f) of 0.28. The pipeline has a length (  L) of 15 meters, an inner diameter (  D) of 0.1 meters, and the water velocity (v) is 40 m/s. Calculate the pressure drop (J) using the given parameters.