Fluid Dynamics

Question 1

what is Venturi effect in your own words?

Answer 1

If we decrease
- as we get narrower, pressure decreases and velocity increases
V1a1 = V2a2
- this is because energy has to be conversed via Bernoulli’s equation

Question 2

Bernoulli’s equation and the three forms of energy

Answer 2

P1 + rho g h + 1/2 rho v^2

P1 = pressure/energy exerted on walls

2nd part: potential energy of the liquid

3rd part: resemblance of kinetic energy

Question 3

Pouseille’s law for laminar flow rate

Answer 3

Q = delta P * pi *r^4 / 8 n l

n: viscosity
L: length

Question 4

Dynamic pressure

- what is this usually used to calculate

Answer 4

Is the difference of stagnated and static pressure = 1/2 rho v^2
- usually used to calculate velocity

Question 5

What are the units of viscosity and what is another way to think of this?

Answer 5

• Pa*s
• momentum / surface area
• N s / m^2

Question 6

What factors are Reynold’s number directly proportional to?

Answer 6

Density, velocity, temperature, and diameter

Inverse to viscosity

Question 7

What is the continuity equation

Answer 7

A1v1 = A2v2

Question 8

What is root mean square

Answer 8

Measure of speed of particles in a glass, square root of average velocity squared of the molecules in a gas (looks at molecular weight and temperature) > affect KE

Question 9

Formula for RMS

Answer 9

RMS = square root (3RT / Molar Mass)

RMS is proportional to square root of kinetic energy