1st law of Thermodynamics - Open Systems

Question 1

What quantities flow across the control volume boundaries?

Answer 1

mass, it is taken into account in the energy equations

Question 2

What can be said about the work requirement for a compression process?

Answer 2

it is lowest for an isothermal process

Question 3

Do all properties remain constant with time in a control volume?

Answer 3

yes

Question 5

Describe what is happening in a control volume for a steady flow process

Answer 5

*fluid flowing through CV in a steady manner
*all properties within the CV remain constant
*no properties change at the boundary with time
*heat and work don’t vary with time

Question 6

What is the flow work?

Answer 6

energy required to push fluid in or out of the control volume

Question 7

What does a turbine do?

Answer 7

a gas or liquid passes through a set of blades attached to a shaft is free to rotate to generate power

Question 8

What does a pump do?

Answer 8

equires work to be done to increase the pressure and/or elevation of a liquid

Question 9

What does a nozzle do?

Answer 9

has a flow passage of varying cross-sectional area in which the velocity of a gas or liquid increases in the direction of flow.

Question 10

What does a diffuser do?

Answer 10

has a flow passage of varying cross-sectional area in which the velocity of a gas or liquid decreases in the direction of flow.

Question 11

What does a compressor do?

Answer 11

requires work to be done to increase the pressure and/or elevation of a gas