Fluid mechanic problem

  • Thread starter sykiat89
  • Start date
  • #1
2
0
given an incompressible steady flow over a converging duct, the outlet velocity can be found just by using mass continuity equation, v1A1=v2A2.

However given a time dependent inlet velocity ie. oscillating velocity, how do i get the outlet velocity? assume the flow is incompressible and inviscid. Tried looking for navier-stoke i had no clue what it does.
 

Answers and Replies

  • #2
boneh3ad
Science Advisor
Insights Author
Gold Member
3,271
945
Continuity still holds even if your inlet is time-dependent.
 
  • #3
2
0
Continuity still holds even if your inlet is time-dependent.

so, the equation, a1v1=a2v2 is applicable unless it is compressible flow? the last i remembered it is only for steady flow, and non of the books has a worked example for time-dependent inlet flow.
 
  • #4
minger
Science Advisor
1,496
2
If the flow is incompressible then that implies instantaneous "information" propagation. That is, any changes at the inlet will be immediately felt at the outlet.

Basically if you draw a control volume everything, since there can be no accumulation inside the CV due to incompressibility, then any changes at the inlet are immediately felt at the outlet.

So, yes, you're simple continuity equation should hold.
 

Related Threads on Fluid mechanic problem

  • Last Post
Replies
6
Views
7K
  • Last Post
Replies
3
Views
2K
Replies
1
Views
1K
Replies
3
Views
1K
  • Last Post
Replies
2
Views
2K
  • Last Post
Replies
5
Views
3K
  • Last Post
Replies
1
Views
2K
  • Last Post
Replies
6
Views
6K
Replies
2
Views
2K
  • Last Post
Replies
5
Views
743
Top