week 1

Question 1

Reversible Isothermal Expansion (process 1-2, TH = constant)
Reversible Adiabatic Expansion (process 2-3, temperature drops from TH to TL)
Reversible Isothermal Compression (process 3-4, TL = constant)
Reversible Adiabatic Compression (process 4-1, temperature rises from TL to TH)

Answer 1

Question 2

Cold-air-standard assumptions
Air-standard cycle

Answer 2

When the working fluid is considered to be air with constant specific heats at room temperature (25°C).
A cycle for which the air-standard assumptions are
applicable.

Question 3

The First Law of Thermodynamics (Overall conservation of Energy)

Answer 3

Question 4

Stagnation enthalpy

Answer 4

The enthalpy of a fluid when it is brought to rest adiabatically.
We will refer to it as Total Enthalpy ht2

Question 5

Air-fuel ratio (AF)

Answer 5

Air-fuel ratio (AF) is usually expressed on a mass basis and is defined as the ratio of the mass of air to the mass of fuel for a combustion process

Question 6

Stoichiometric or theoretical air

Answer 6

The minimum amount of air needed for the omplete combustion of a fuel. Also referred to as the chemically correct amount of ir, or 100% theoretical air. E.g. 1 kg of petrol requires 14.8 kg stoichiometric air

Question 7

Excess air

Answer 7

The amount of air in excess of the stoichiometric amount. Usually expressed in terms of the stoichiometric air as percent excess air or percent theoretical air.

Question 8

Deficiency of air

Answer 8

Amounts of air less than the stoichiometric amount. Often expressed as percent deficiency of air

Question 9

Equivalence ratio

Answer 9

The ratio of the actual fuel–air ratio to the stoichiometric fuel–air ratio.