Help with entrance effects for fluid please

  • Thread starter Thread starter JI567
  • Start date Start date
  • Tags Tags
    Effects Fluid
Click For Summary

Discussion Overview

The discussion focuses on the significance of entrance effects for a fluid entering a circular pipe, comparing the fully developed region and laminar region, among others. Participants explore the implications of these effects on fluid dynamics.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • Some participants assert that entrance effects are very important in fluid dynamics.
  • One participant questions the significance of entrance effects, suggesting that the fluid simply enters and flows uniformly without major implications.
  • Another participant describes the fluid's behavior as it enters the pipe, noting that it accelerates and has radial velocity, which leads to entrance separation and the vena contracta, resulting in pressure loss.
  • A proposal is made that using a tapered horn at the pipe entrance could help regulate flow and mitigate the vena contracta effect.

Areas of Agreement / Disagreement

Participants express differing views on the significance of entrance effects, with some emphasizing their importance while others question their impact, indicating that the discussion remains unresolved.

Contextual Notes

There are unresolved assumptions regarding the definitions of entrance effects and their implications on flow characteristics, as well as the conditions under which these effects are significant.

JI567
Messages
173
Reaction score
0
Can anyone tell me how significant are entrance effects for a fluid entering a circular pipe? Like the fully developed region, laminar region etc. comparison between these regions...
 
Engineering news on Phys.org
Baluncore said:
Entrance effects are very important.
http://en.wikipedia.org/wiki/Vena_contracta
google images 'vena contracta'

It talks about Vena contract and nothing about entrance effect. I mean a fluid enters with uniform speed inside a circular pipe and then just flows, I mean what's the big deal here? Its just entering and flowing...don't get it
 
The fluid moves as a radial flow towards the pipe entrance. As it enters the pipe it is still accelerating and still has radial velocity. That causes the entrance separation and the vena contracta which together represent a pressure loss and an obstruction to flow like an orifice. If a tapered horn like a trumpet is mounted at the pipe entrance then the flow can be better regulated and the vena contracta avoided.
 

Similar threads

How can I avoid Foaming in my cutting fluid tank? (attached drawing for reference)
  • · Replies 18 ·
Replies
18
Views
3K
Doublet flow in Fluid Dynamics between two spheres or cylinders
  • · Replies 0 ·
Replies
0
Views
3K
The Venturi Effect cannot explain how an eductor works
  • · Replies 2 ·
Replies
2
Views
4K
Undergrad Assumptions for Navier Stokes equations in this system
  • · Replies 3 ·
Replies
3
Views
2K
Please tell me the difference in the size of the air volume
  • · Replies 3 ·
Replies
3
Views
1K
Which Pump Can Safely Circulate Fluid with Glass Spheres?
  • · Replies 24 ·
Replies
24
Views
4K
Theoretical Pipe Flow: Understanding Poiseuille's Law
  • · Replies 4 ·
Replies
4
Views
2K
Transitional Reynolds Number When Analysing Flow Through Orifices
  • · Replies 4 ·
Replies
4
Views
2K
Turbulent Viscosity: Definition & Effects on Flow
  • · Replies 5 ·
Replies
5
Views
5K
Construction of a model of a hydraulic damper
  • · Replies 21 ·
Replies
21
Views
3K