Part 2 Flashcards
(21 cards)
What is the continuity equation (compressible)?
πβπ΄βπβ = πβπ΄βπβ
What is the continuity equation for incompressible flow?
π΄βπβ = π΄βπβ
What is steady flow?
Flow parameters at any point do not change with time.
What is a control volume?
A fixed region in space through which fluid can flow in and out.
When is flow incompressible?
When Ξπ/π < 5%, typical for liquids and low-speed gases.
What is momentum flow rate?
πΛπ = ππ΄πΒ²
What is the momentum equation for 1D flow?
βπΉ = πΛβπβ β πΛβπβ
What forces are considered in the momentum equation?
Pressure and body forces (like gravity); viscous forces neglected for inviscid flow.
What happens to the force if jet velocity doubles?
Force increases fourfold: πΉ β πΒ²
What is the Euler equation?
ππ/ππ₯ = βππ ππ/ππ₯
What is the Bernoulli equation (simplified)?
π + 1/2 ππΒ² = constant
What are the assumptions for Bernoulliβs equation?
Steady, incompressible, inviscid flow along a streamline.
What is stagnation pressure?
πβ = π + 1/2 ππΒ²
How is Pitot tube velocity calculated?
π = β(2(pβ β πβ)/π)
What does Bernoulliβs equation imply about pressure and velocity?
As velocity increases, pressure decreases.
What is a streamline?
A line tangent to the velocity vector at every pointβno flow crosses it.
What is a streakline?
A line formed by fluid particles that have passed through a point over time.
What is a pathline?
The actual trajectory of a fluid particle over time.
What is a timeline?
A line formed by multiple fluid particles at one instant in time.
What happens to streamlines in a converging duct?
They converge, indicating increased velocity.
What does parallel streamlines indicate?
Constant velocity (uniform flow).
