How Do You Calculate Air Flow Velocity Between Two Tanks?

  • Context: Undergrad 
  • Thread starter Thread starter supernova1387
  • Start date Start date
  • Tags Tags
    Flow Velocity
Click For Summary

Discussion Overview

The discussion revolves around calculating the air flow velocity between two tanks, one at atmospheric pressure and the other under vacuum, connected by a pipe with a valve. Participants explore the assumptions and factors affecting flow velocity, including the nature of the flow and the properties of the pipe.

Discussion Character

  • Technical explanation, Conceptual clarification, Debate/contested

Main Points Raised

  • One participant questions how to calculate the air velocity when a valve is opened between a tank at 1 bar and a vacuum tank, expressing uncertainty about the applicability of Bernoulli's principle due to the non-steady nature of the flow.
  • Another participant suggests that flow velocity is influenced by the thickness and length of the pipe, as well as the temperature of the air.
  • A third participant refines the terminology by stating that 'internal diameter' is a more appropriate term than 'thickness' when discussing the pipe.
  • Additionally, a participant notes that the flow will initially be choked and will later un-choke as the pressures in the tanks equalize, indicating a dynamic change in flow conditions.

Areas of Agreement / Disagreement

Participants express differing views on the factors affecting flow velocity and the applicability of Bernoulli's principle, indicating that multiple competing perspectives remain in the discussion.

Contextual Notes

Assumptions regarding the flow conditions, pipe characteristics, and the behavior of air under varying pressures are not fully defined, leading to potential limitations in the discussion.

supernova1387
Messages
30
Reaction score
0
This might be simple but I can't remember how to do it.

problem: we have 2 tanks. One filled with atmospheric air at 1 bar and the other is vacuum. The two tanks are connected by a rigid pipe which has a valve. I open the valve and air flows to the vacuum tank. How do I calculate the air velocity?

P.s: I don't think Bernoulli is valid here because the flow isn't steady I guess. Please state your assumptions clearly.

Thanks in advance
 
Physics news on Phys.org
Flow velocity depends on the thickness and length of the pipe, and on the temperature of the air.
 
Instead of 'thickness' of the pipe, the term 'internal diameter' would be more apt.
 
Also pay attention to the pressures. The flow is going to start off choked but will eventually un-choke as the pressures equalize.
 

Similar threads

Undergrad Flow rate calculation of coating application
  • · Replies 30 ·
2
Replies
30
Views
3K
Graduate Air flow through a hole in a submerged pressure tank
  • · Replies 13 ·
Replies
13
Views
21K
Undergrad How much time to pressure balance two air chambers
  • · Replies 4 ·
Replies
4
Views
2K
Graduate Calculating Filling Time for a Diving Tank with Changing Hydrostatic Pressure
  • · Replies 2 ·
Replies
2
Views
2K
Undergrad Pipe Air Blowing - Exit Velocity of Air
  • · Replies 19 ·
Replies
19
Views
4K
Undergrad Drag equation - relative flow velocity
  • · Replies 11 ·
Replies
11
Views
4K
Graduate Flow of air through an open tube with a balloon
  • · Replies 9 ·
Replies
9
Views
4K
Undergrad Velocity of compressed air through pipe
  • · Replies 1 ·
Replies
1
Views
2K
Undergrad Air flow velocity - big to small and vice versa
  • · Replies 3 ·
Replies
3
Views
8K
How to determine air velocity in open ended tube?
  • · Replies 9 ·
Replies
9
Views
2K