# Conduction of Heat and Overall Heat Transfer Along a Composite Bar

Topics: Thermodynamics, Temperature, Heat Pages: 4 (907 words) Published: January 22, 2013
OBJECTIVE:
1. To demonstrate the isentropic expansion process.

INTRODUCTION:
In thermodynamics, an isentropic process is one in which for purposes of engineering analysis and calculation, one may assume that the process takes place from initiation to completion without an increase or decrease in the entropy of the system .If a compression or expansion of a gas takes place with no flow of heat energy either into or out of the gas - the process is said to be isentropic or adiabatic. The isentropic (adiabatic) process can be expressed with the Ideal Gas Law as: p / ρk = constant

where
k = cp / cv - the ratio of specific heats - the ratio of specific heat at constant pressure - cp - to the specific heat at constant volume - cv The isentropic or adiabatic process can also be expressed as pVk= constant

or
p1V1k  = p2V2k

The Second law of thermodynamics states that,

where δQ is the amount of energy the system gains by heating, T is the temperature of the system, and dS is the change in entropy. The equal sign will hold for a reversible process. For a reversible isentropic process, there is no transfer of heat energy and therefore the process is also adiabatic. For an irreversible process, the entropy will increase. Hence removal of heat from the system (cooling) is necessary to maintain a constant internal entropy for an irreversible process in order to make it isentropic. Thus an irreversible isentropic process is not adiabatic. For reversible processes, an isentropic transformation is carried out by thermally "insulating" the system from its surroundings. Temperature is the thermodynamic conjugate variable to entropy, thus the conjugate process would be an isothermal process in which the system is thermally "connected" to a constant-temperature heat bath.

MATERIAL AND METHODOLOGY:
Material: -
Apparatus: Perfect gas expansion unit.

Methodology:
1. The general start up procedures as stated in Appendix A were...