TECHNICAL TERMS OF THERMODYNAMICS NICELY EXPLAINED !!

1.)ABSOLUTE TEMPERATURE SCALES – Used for calculating changes in refrigerant vapour pressures.

2.)ADIABATIC EXPANSION or COMPRESSION – Expansion or compression where the temperature rises during compression and falls during expansion without any loss of heat to the cylinder walls or
absorption of heat from the walls.

3.)ADIABATIC HEAT DROP – The heat energy released and theoretically capable of transformation into mechanical work during the adiabatic expansion of unit weight of steam or other vapour or gas.

4.)AIR STANDARD EFFICIENCY – The thermal efficiency of an internal combustion engine working on the appropriate air standard cycle.

5.)AMBIENT TEMPERATURE – Temperature (usually of the air) surrounding the operating equipment.

6.)ATMOSPHERIC PRESSURE – Force exerted by the weight of the atmosphere on every point with which it is in contact. It is generally taken as 1.03 kscm at sea level.

7.)AVAGADRO’S LAW – Equal volumes of different gases at the same temperature and pressure contain the same number of molecules.

8.)BOUNDARY– is a real physical surface or an imaginary surface enclosing some matter. The boundary may be a fixed one or a varying one.

9.)BOYLE’S LAW – The absolute pressure of a gas will vary inversely as the volume, if the temperature remains constant. Or conversely, the volume will vary inversely as the absolute pressure, if the temperature remains constant.

10.)CHARLE’S LAW – At constant pressure, the volume of a gas is proportional to its absolute temperature. At constant volume, the pressure is proportional to its absolute temperature.

11.)CLOSED SYSTEM – The system which will have boundaries across which both heat and work can penetrate, but no mass will be permitted to cross them.

12.)COEFFICIENT OF EXPANSION – The fractional increase in length or volume per degree rise in temperature.

13.)JOULE’S LAW OF INTERNAL ENERGY – The internal energy of a given quantity of a gas depends only on the temperature of the gas. As temperature changes, the internal energy also changes.

14.)KELVIN PLANK STATEMENT– It is impossible to construct an engine undergoing a cyclic process, which will convert all the heat supplied to it into an equivalent amount of work.

15.)MEAN EFFECTIVE PRESSURE – The difference between the mean forward pressure and the mean back pressure acting on a moving piston during a cycle of operation.