MAAE 2300 S25 Midterm 2

What do we call the viewpoint of following fluid particles

Lagrangian

What do we call the viewpoint of studying the control volume

Eulerian

How is the flowrate found through surface with varying velocity

Using the average velocity

What creates a velocity profile in a fluid?

Shear stress

What are four conditions that discern free flow from the boundary layer

Flow far from the surface

Negligible velocity gradients

Negligible shear stress

Significant inertia effect

How is the boundary layer defined?

Distance below which the difference in flow from the free stream is above 1%

What is true for the boundary layer within a pipe?

If flow is internal, the boundary layer converges and the whole pipe is a boundary layer

What does reynolds transport theorem do?

Convert a system analysis to a control volume analysis

What are 7 types of flows

Steady and Unsteady

Uniform and Non Uniform

Viscous and Inviscid

Laminar and TUrbulent

External and Internal

Incompressible and Compressible

One, Two and Three dimensional

What does steady flow imply

Volume, Density, Pressure and Temperature do not change with time for a point

What does uniform flow imply

Velocity, Pressure, temperature do not vary across an area C/S

What does laminar flow imply

Layers shear over top eachother

What type of fluids are likely to experience turbulence?

Flows with low viscosity at high expeed

What type of flows are compressible

High speed gas

What are four ways to visualize flow

Streamline, Pathline, Streakline, Timeline

What is true about streamlines (3 points)

Velocity is tangent

No crossing

May vary with time

What is a pathline (3pts)

Actual path of a farticle

Obtained by releasing a particle and observing it

Can be sued to find average velocity

What is a streakline (3pts)

Pass through many particles at the same point in tame that started from the same origin. They may have started at different times.

Have the same origin

Found with dye

What is true for steady flow

Streamlines, streaklines and pathlines all coincide

How do we find the gradient line of a rigid body flow?

This is the orthogonal trajectory of the isobars. Moving along this line will give larger pressures.

What does the gradient line depend on?

only the angular velocity and initial condition

What are three terms in the bernoulli equation (energy)

Flow energy, Kinetic energy, Potential energy

What are the assumptions of Bernoulli’s Equation

Steady, Inviscid, Incompressible

What are three terms in the bernoulli equation (egl)

Pressure head, Velocity head, Elevation head

What are the three terms of the bernoulli equation (pressure)

static pressure, dynamic pressure, hydrostatic pressure

equal to stagnation pressure

What is the HGL?

Sum of pressure head and elevaiton head

What are the nine limitations of the Bernoulli equation

Steady flow, Frictionless flow, No shaft work, Incompressible flow, No heat transfer, Flow along a streamline

Where is the bernoulli equation invalid

Boundery layer or wake

What is the pressure formula