# Pressure Drop in vacuum cleaners

1. Nov 26, 2016

### Marylaax

1. The problem statement, all variables and given/known data

Q = A / V
Bernollis therom → γH = P+γZ+ρ.v2 /2
Air Flow Speed = 0.058 m3/s
A = Section Area of the tube = π.r2
r = 19.65 mm
ρ =1000 kg/m3
g =9.8 m/s2
P=pressure energy of water = 2.338

2. Relevant equations
Find :
V= Fluid Velocity = ?
H=Energy Denisty = ?
Z= Geodesic Height = ?

3. The attempt at a solution

Last edited by a moderator: May 8, 2017
2. Nov 26, 2016

### Nidum

Could you please explain what the actual problem is that you are trying to solve ?

3. Nov 26, 2016

### Marylaax

We need to calculate the pressure drop in a professional Vacuum Cleaner

4. Nov 26, 2016

### billy_joule

It's still not clear what you're trying to do.
Pressure drop when and where? When the vacuum is being used or not? At what flow rate?
The pressure drop when the vacuum isn't being used is mainly due to the dirt separation assembly and as most vacuums have a combination of a cyclone separator, foam filter/s and complex flow paths, it can't be found by hand calculations. CFD or testing is needed. If you add additional restrictions, like vacuuming some carpet, the problem becomes even harder.

So presumably you've been given some unrealistic, simplified problem that can be solved with Bernoulli's equation. Tell us that problem and we might be able to make some progress.