## What does the law of Hagen and Poiseuille describe?

The Hagen–Poiseuille equation describes the relationship between pressure, fluidic resistance and flow rate, analogous to voltage, resistance, and current, respectively, in Ohm’s law for electrical circuits ( V = R I ). Both electrical resistance and fluidic resistance are proportional to the length of the device.

## What is the assumption of Hagen Poiseuille equation?

The assumptions of the equation are that the fluid is incompressible and Newtonian; the flow is laminar through a pipe of constant circular cross-section that is substantially longer than its diameter; and there is no acceleration of fluid in the pipe.

What does Poiseuille’s law show?

Poiseuille’s Law. The flow of fluids through an IV catheter can be described by Poiseuille’s Law. It states that the flow (Q) of fluid is related to a number of factors: the viscosity (n) of the fluid, the pressure gradient across the tubing (P), and the length (L) and diameter(r) of the tubing.

### What are the limitations of Poiseuille’s law?

Limitations. Poiseuille’s law, in its original form, can be used only for Newtonian fluids in tubes whose length is much more than the width. The steady-state described above won’t be met and the equation will not be valid if the tube is too broad or length too short.

### What is Poiseuille’s formula derive an expression for it?

The Poiseuille’s Law formula is given by: The Pressure Gradient (∆P) Shows the pressure differential between the two ends of the tube, defined by the fact that every fluid will always flow from the high pressure (P1) to the low-pressure area (P2) and the flow rate is calculated by the ∆P = P1-P2.

Which assumption is not used for deriving the Poiseuille’s flow equation?

Assumptions in Fluid Calculations In order to use Poiseuille’s law in fluid calculations, it is necessary to assume that the flow is laminar and that there is no turbulence. This is often an invalid assumption since many common flow phenomena exceed the critical speeds at which turbulence begins.

## What is Poiseuille’s law class 11?

the law that the velocity of a liquid flowing through a capillary is directly proportional to the pressure of the liquid and the fourth power of the radius of the capillary and is inversely proportional to the viscosity of the liquid and the length of the capillary.