Test 2 Concept Questions Flashcards
What is a Streamline?
A line through moving fluid such that the velocity vector is tangential to it at all points.
What are the different components of acceleration?
Local (dv/dt)
Convective (V(dv/dx))
Centripetal (v^2/r)
What is the basic assumption involved in Euler’s
Assumes that mass accelerates as a whole and friction and viscous forces are ignored
What assumptions are involved in Bernoulli’s Equation
Assumes steady flow and no viscous forces or friction
What is the relationship of pressure in the rotating fluid at the center fo the fluid and at a point just outside the fluid
The pressure at the center of the rotating fluid is lower (think hurricane)
What is the physical meaning of each term in Bernoulli’s equation?
P = Pressure Force z = Weight Force v^2/(2g) = Convective Acceleration
Bernoulli’s in a streamline vs two points in a flow field
They are the same as long as the flow field has constant velocity and is irrotational.
What is irrotational flow/ideal flow/ideal fluid/non-viscous/inviscous fluid?
Steady flow/zero viscosity
What is stagnation pressure?
Static Pressure + Dynamic Pressure
What is a control volume?
A fixed volume/space in a flow field?
Steady Flow vs. Unsteady flow
If the flow properties or fluid properties are changing with time at a given point in space (CV), the flow is unsteady.
What are the direction and orientation of fo unit vectors with respect to control surfaces?
Normal and must point outwards from the control surface
What do steady flows mean in terms of mass conservation?
The rate of change of amass in a CV is 0
Under what conditions does mass conservation reduce to volume conservation?
If the flow is incompressible and the density is constant within CV and at the inflows/outflows then it can be reduced.
What do steady flows mean in terms of momentum conservation?
Momentum in CV is constant
