Why thrust decreases then increases with velocity?

  • Thread starter Thread starter dale_8888
  • Start date Start date
  • Tags Tags
    Thrust Velocity
AI Thread Summary
Thrust behavior in engines varies with velocity due to the interplay of pressure and momentum thrust. Initially, net thrust decreases as velocity increases because pressure thrust diminishes while momentum thrust is not yet fully realized. As velocity continues to rise, momentum thrust increases due to higher mass flow rates, leading to an eventual increase in net thrust. Clarification is needed on whether the discussion pertains to jet engines or fluid dynamics from a pressurized source. Understanding these dynamics is crucial for analyzing thrust variations with changing velocities.
dale_8888
Messages
1
Reaction score
0
Hello,

I was trying to find out why net thrust decreases then increases with velocity. I recall there is pressure and momentum thrust, however I can not recall why one of them falls away and the other increases.

Is momentum thrust the one that picks up as the mass flow increases with increased velocity?
 
Physics news on Phys.org
I'm afraid you will have to give more information. What "thrust" are you talking about? Is this a jet engine or a fluid leaving a source under pressure?
 

Thread 'Average velocity as a weighted mean'

Hello everyone, Consider the problem in which a car is told to travel at 30 km/h for L kilometers and then at 60 km/h for another L kilometers. Next, you are asked to determine the average speed. My question is: although we know that the average speed in this case is the harmonic mean of the two speeds, is it also possible to state that the average speed over this 2L-kilometer stretch can be obtained as a weighted average of the two speeds? Best regards, DaTario
View full post »

Thread '1:1 versus 2:1 Mechanical Advantage debate'

The rope is tied into the person (the load of 200 pounds) and the rope goes up from the person to a fixed pulley and back down to his hands. He hauls the rope to suspend himself in the air. What is the mechanical advantage of the system? The person will indeed only have to lift half of his body weight (roughly 100 pounds) because he now lessened the load by that same amount. This APPEARS to be a 2:1 because he can hold himself with half the force, but my question is: is that mechanical...
View full post »

Thread 'Newton's first law?'

Some physics textbook writer told me that Newton's first law applies only on bodies that feel no interactions at all. He said that if a body is on rest or moves in constant velocity, there is no external force acting on it. But I have heard another form of the law that says the net force acting on a body must be zero. This means there is interactions involved after all. So which one is correct?
View full post »

Similar threads

I Understanding the thrust generated by a typical jet engine
Replies
2
Views
2K
Optimal Size of Rocket Engine Nozzle for Vacuum Performance
Replies
26
Views
3K
Conservative forces, Nonconservative forces and Potential Energy
Replies
9
Views
3K
Thrust/Force and Angular Velocity
Replies
3
Views
4K
Why Do Quadcopter Control Equations for Roll and Pitch Exclude Aerodynamic Drag?
Replies
2
Views
1K
I Can a Satellite Maintain its Angular Velocity with Continuous Low Thrust?
Replies
2
Views
2K
Rocket propulsion explained only through pressure differential
Replies
46
Views
5K
Rocket thrust equation in under-expanded nozzle
Replies
2
Views
4K
EDF Rocket with Thrust Tube: Physics Explained
Replies
8
Views
3K
Why Does Acceleration Decrease When Velocity Increases in SHM?
Replies
9
Views
4K

Hot Threads

Recent Insights

Back
Top