Convection

Question 1

convective mass balance

steps to derive

Answer 1

1. define N, absolute flux
2. is it dilute?
3. Consider the bulk velocity of the fluid

Question 2

Give me the convective energy balance

Answer 2

Question 3

Give me the simplifed viscous dissipation

Answer 3

for incompressible fluid

Question 4

What does Nussult no.
give

Answer 4

Ratio of convection : conduction

• h = convective heat transfer
• L = length
• k = thermal conductivity (W/m2K)

Question 5

Prandtl number

Answer 5

momentum : thermal
diffusivity

𝜇 = dynamic viscosity
k = diffusivity

Question 6

When to use Sherwood no.
Schmidt number
+
Nussult
Prandlt

Answer 6

S + S : mass transfer
N + P : heat transfer

Question 7

Sherwood Number

Answer 7

Convection vs diffusion

Question 8

Schmidts number

Answer 8

momentum vs mass
diffusivity

Question 9

What are Sherwood and Nusselt for

Answer 9

compare convection
against
pure conduction/diffusion

Question 10

What are Schmidts + Prandlt number for

Answer 10

Compare momentum vs
thermal/mass diffusivity

Question 11

What is the erf function derivative

Answer 11

Question 12

when to use an error function?

How to apply it to undeveloped flow problem

Answer 12

When there’s the derivative of both dC/dx and dC/dy
and similar function is applied

Question 13

how to solve for the flux when

Answer 13