#### Hagen–poiseuille equation

## What does Poiseuille’s law explain?

Definition. 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.

## Which among the following is an 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 is the velocity profile for Poiseuille flow?

When the flow is fully developed and laminar, the velocity profile is parabolic. Within the inlet length, the velocity profile changes in the direction of the flow and the fluid accelerates or decelerates as it flows. There is a balance among pressure, viscous, and inertia (acceleration) forces.

## How is Poiseuille’s equation used in determining the relative viscosity?

As indicated by the Poiseuille equation [5.1], blood viscosity is directly related to vascular resistance and indirectly related to blood flow. Blood viscosity is a direct function of hematocrit. Thus, as hematocrit decreases with hemodilution, blood viscosity decreases, and blood flow increases.

## How do I calculate flow rate?

Q=Vt Q = V t , where V is the volume and t is the elapsed time. The SI unit for flow rate is m^{3}/s, but a number of other units for Q are in common use. For example, the heart of a resting adult pumps blood at a rate of 5.00 liters per minute (L/min).

## What is poiseuille number?

Poiseuille number (Po) A non-dimensional number which characterizes steady, fully-developed, laminar flow of a constant-property fluid through a duct of arbitrary, but constant, cross section and defined by Access to the complete content on Oxford Reference requires a subscription or purchase.

## How does flow rate depend on diameter?

In general, the flow rate increases proportional to the square of the inside diameter, hence the flow rate is directly proportional to the area of pipe cross-section. The larger the diameter, the greater flow.

## What is the total loss developed in a series of pipes?

2. What is the total loss developed in a series of pipes? Explanation: When the pipes of different diameters are connected in series from end to end to form a pipe line. The total loss so developed is equal to the sum of local losses plus the losses in each pipe.

## What is meant by pressure drop?

Simply put, pressure drop is the difference in total pressure between two points in a fluid-carrying network. When a liquid material enters one end of a piping system, and leaves the other, pressure drop, or pressure loss, will occur. Pressure drop in and of itself is not necessarily bad.

## What is transition flow?

A flow in which the viscous and Reynolds stresses are of approximately equal magnitude. It is transitional between laminar flow and turbulent flow.

## Is blood a Newtonian fluid?

The blood is a non-Newtonian fluid and it follows Newtonian nature when the shear rate is above 100 s^{–}^{1} [3,4]. The effect of non-Newtonian behavior of flow is not significant in large blood vessels like aorta, where the shear rate is high.

## How is viscosity calculated?

There are several formulas and equations to calculate viscosity, the most common of which is Viscosity = (2 x (ball density – liquid density) x g x a^2) ÷ (9 x v), where g = acceleration due to gravity = 9.8 m/s^2, a = radius of ball bearing, and v = velocity of ball bearing through liquid.

## How does viscosity affect flow rate?

Thicker fluids flow slower than thinner fluids. b) The flow rate and viscosity are connected because the viscosity of the fluid affects the flow rate. If a fluid has a low viscosity, it means that there will be a high flow rate. If a fluid has a high viscosity, it will have low flow rate.