Module 1 Concepts

Question 1

What are the conditions of use of the continuity equation for mass flow rate?

Answer 1

-Must be streamline flow

Question 2

What are the conditions for the use of the continuity equation for volumetric flow rate?

Answer 2

• Must be streamline flow

- Must be incompressible

Question 3

What is the definition of a streamline?

Answer 3

A one that dhows the direction of flow of a fluid at any particular moment.
A line drawn tangental to a point will show the velocity vector at that point.

Question 4

What are the conditions for the use of Bernoulli’s equation?

Answer 4

• Incompressibility
• Steady State
• Streamline
• There is no friction

Question 5

What does Bernoulli’s equation show?

Answer 5

For the flow an an incompressible ideal fluid along its streamline, the sum of potential energy and kinetic energy and the capability to produce work due to pressure at any point along the streamline is constance

Question 6

What is stagnation pressure, temperature, density?

Answer 6

It is the pressure, temperature and density of the air when the velocity is 0.

Question 7

Below what speed can air be treated as incompressible?

Answer 7

250 knots

Question 8

What is the principal of operation of a pitot tube?

Answer 8

One tube measures the stagnation (total) pressure. The other measures static pressure from a port opening parallel to the airflow.
A pressure transducer between the static and total pressure chambers will be measured by this.

Pd = Pt - Ps

Question 9

What is an isothermal process? What is an example?

Answer 9

Temperature of a gas system is kept constant.

eg. A balloon is slowly compressed at atmospheric conditions

Question 10

What is an isobaric process? What is an example?

Answer 10

Pressure of a gas system is kept constant in a thermal process
eg. Gas expanding inside a cylinder will change volume and temperature but not pressure

Question 11

What is an isochoric process? What is an example?

Answer 11

Also called isovolumetric. It is where the volume/ density of a gas system is kept constant in a thermal process.
eg. gas in seal container is increased in temp and pressure

Question 12

What is an adiabatic process? What is an example?

Answer 12

There is no transfer of heat from the system to outside. It converts all of its internal energy into work.
eg. Airflow over an aerofoil

Question 13

According to Bernoulli’s equation what happens to kinetic energy and static pressure when velocity is increased?

Answer 13

Static pressure is decreased

Kinetic energy increases

Question 14

Can a substance undergo multiple thermal processes at the same time?

Answer 14

No

Question 15

What thermal process(es) can the energy equation be applied to?

Answer 15

Adiabatic

Question 16

What does the Energy Equation show?

Answer 16

the sum of thermodynamic potential energy and kinetic energy of gas of unit mass along a streamline is constant if this isolated system has not heat exchange externally