Understanding Venturi Pump: Calculating Fluid Flow and Suction Speed

[Idea04]

Homework Statement

on a venturi pump the fluid, air or water move through a narrow tube and increases speed and also decreases pressure. Now I have read before that the dynamic pressure and the static pressure are added to get the total pressure. How fast does the fluid have to flow to create suction?

Homework Equations

The Attempt at a Solution

 

[Astronuc]

The suction depends on the fluid velocity and relative sizes of the jet and nozzle.

See this demo -

http://www.ce.utexas.edu/prof/kinnas/319LAB/Applets/Venturi/venturi.html

 

[m2003]

I would like to clarify that a venturi pump is a type of fluid flow device that uses the Venturi effect to create a pressure difference and move fluids. The principle of the Venturi effect states that as a fluid flows through a constricted section of a pipe, the velocity of the fluid increases, while the pressure decreases. This is due to the conservation of energy and the decrease in cross-sectional area of the pipe.

To calculate the fluid flow and suction speed in a venturi pump, the Bernoulli's equation can be used. This equation relates the pressure, velocity, and height of a fluid at different points along a streamline. In the case of a venturi pump, the equation can be simplified to:

P1 + 1/2ρv1^2 + ρgh1 = P2 + 1/2ρv2^2 + ρgh2

Where P1 and P2 are the pressures at the two points, ρ is the density of the fluid, v1 and v2 are the velocities at the two points, g is the acceleration due to gravity, and h1 and h2 are the heights at the two points.

To create suction, the pressure at the narrow part of the venturi pump (P2) must be lower than the pressure at the wider part (P1). This can be achieved by increasing the velocity at the narrow part, which will decrease the pressure according to the Bernoulli's equation. The fluid flow rate and suction speed can be calculated by solving the Bernoulli's equation for v1 or v2, depending on the known variables.

In summary, the fluid must flow at a sufficient velocity at the narrow part of the venturi pump to create a pressure difference and generate suction. The exact velocity required will depend on the specific design and dimensions of the pump.