Pressure Drop in a vacuum cleaners

AI Thread Summary
The discussion focuses on calculating the pressure drop in a professional vacuum cleaner using Bernoulli's theorem and related equations. Key variables include air flow speed, section area of the tube, and pressure energy of water. Participants highlight the complexity of determining pressure drop due to factors like dirt separation assembly and flow path restrictions, suggesting that computational fluid dynamics (CFD) or empirical testing may be necessary for accurate results. There is a request for clarification on the specific conditions under which the pressure drop is to be measured. Overall, the conversation emphasizes the challenges of calculating pressure drop in vacuum systems without simplifying assumptions.
Marylaax
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Homework Statement


[/B]
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

Homework Equations


Find :
V= Fluid Velocity = ?
H=Energy Denisty = ?
Z= Geodesic Height = ?

The Attempt at a Solution


https://drive.google.com/file/d/0B49nLOs3rXGEbXJOemhyQU5IaTg/view?usp=sharing
 
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Could you please explain what the actual problem is that you are trying to solve ?
 
Nidum said:
Could you please explain what the actual problem is that you are trying to solve ?
We need to calculate the pressure drop in a professional Vacuum Cleaner
 
Marylaax said:
We need to calculate the pressure drop in a professional Vacuum Cleaner

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.
 
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