Venturi pipe in engine exhaust flow

Click For Summary
SUMMARY

The discussion centers on optimizing vacuum in engine exhaust flow using Venturi pipes for crankcase exhaust ventilation. Two designs are evaluated: one with a birds eye cut and another that provides a better vacuum signal. Participants emphasize the importance of using a flame trap to prevent explosions and suggest that a flush hole in the exhaust pipe may suffice for creating a partial vacuum. Questions regarding normal pressures in the crankcase and exhaust pipe are raised, highlighting the need for effective venting strategies.

PREREQUISITES
  • Understanding of Venturi effect in fluid dynamics
  • Knowledge of engine crankcase ventilation systems
  • Familiarity with exhaust gas flow dynamics
  • Awareness of safety measures such as flame traps in automotive applications
NEXT STEPS
  • Research the principles of the Venturi effect in automotive applications
  • Explore different crankcase ventilation designs and their effectiveness
  • Learn about exhaust gas pressure measurements and their implications
  • Investigate methods for reducing emissions through blow-by gas management
USEFUL FOR

Automotive engineers, mechanics, and enthusiasts interested in optimizing engine performance and emissions through effective crankcase ventilation strategies.

Dteeter
Messages
1
Reaction score
0
20190815_135233.jpg


I would appreciate opinions on this...on which setup would create the best vacuum in an exhaust gas stream? The #1 drawing is a pipe that has a birds eye cut in it. These are sold for engine crankcase exhaust ventilation. There are some that say they work, then others that say they don't work and actually created back pressure in the crankcase. I personally think that #2 would work much better...a better vacuum signal. Thank you.
20190815_135233.jpg
 
Engineering news on Phys.org
Do you intend to use the vacuum for crankcase exhaust ventilation? If so you will need a flame trap to prevent a crankcase explosion.

I do not think you need to penetrate the exhaust flow to such a significant extent. A hole, flush with the internal surface of the exhaust pipe should provide a partial vacuum.

What is the normal positive pressure in a vented crankcase? What is the normal pressure in the exhaust pipe?

Why do you not vent the crankcase to the inlet manifold and burn the blow-by products to reduce emissions?
 

Similar threads

Replies
25
Views
4K
Replies
1
Views
922
  • · Replies 8 ·
Replies
8
Views
4K
  • · Replies 15 ·
Replies
15
Views
4K
Replies
7
Views
2K
  • · Replies 6 ·
Replies
6
Views
3K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 4 ·
Replies
4
Views
4K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 31 ·
2
Replies
31
Views
5K