The Pressure Gradient Equation describes the change in pressure with respect to distance in a fluid flow field. It’s a fundamental equation in fluid mechanics and is commonly used to analyze the behavior of fluids in pipes, channels, and other conduits. Mathematically, the Pressure Gradient Equation can be expressed as:

Where:

• dP​/dx is the pressure gradient, representing the rate of change of pressure with respect to distance,
• $\rho$ is the density of the fluid,
• $g$ is the acceleration due to gravity.