Entropy Change by Heat Transfer Define Thermal Energy Reservoir (TER) –Constant mass, constant volume –No work - Q only form of energy transfer –T uniform.

Slides:



Advertisements
Similar presentations
The Second Law of Thermodynamics
Advertisements

Thermodynamics versus Statistical Mechanics
Department of Mechanical Engineering ME 322 – Mechanical Engineering Thermodynamics Lecture 18 Introduction to 2 nd Law and Entropy.
Kinetic Theory and Thermodynamics
Department of Mechanical Engineering ME 322 – Mechanical Engineering Thermodynamics Lecture 19 Calculation of Entropy Changes.
MEL140 (Second Law: Continued)
State Postulate According to the State Postulate the number of intensive variable needed to specify all other intensive variables equals the number of.
Advanced Thermodynamics Note 4 The Second Law of Thermodynamics
Entropy Cengel & Boles, Chapter 6 ME 152.
ENGR 2213 Thermodynamics F. C. Lai School of Aerospace and Mechanical Engineering University of Oklahoma.
Entropy Change Property diagrams (T-s and h-s diagrams) –From the definition of the entropy, it is known that  Q=TdS during a reversible process. –Hence.
Entropy and the Second Law of Thermodynamics
Lec 18: Isentropic processes, TdS relations, entropy changes
Second Law of Thermodynamics Physics 202 Professor Lee Carkner Lecture 18.
The Second Law of Thermodynamics
Physics 101: Lecture 31, Pg 1 Physics 101: Lecture 31 Thermodynamics, part 2 l Review of 1st law of thermodynamics l 2nd Law of Thermodynamics l Engines.
Entropy Thermodynamics Professor Lee Carkner Lecture 13.
Thermo & Stat Mech - Spring 2006 Class 7 1 Thermodynamics and Statistical Mechanics Tds Equations.
Thermo & Stat Mech - Spring 2006 Class 6 1 Thermodynamics and Statistical Mechanics Entropy and the Second Law of Thermodynamics.
Further Analysis of Reversible Machines P M V Subbarao Professor Mechanical Engineering Department Innovation of A New Property of A System!!!!
Thermodynamics and Statistical Mechanics
Entropy and the Second Law of Thermodynamics
Entropy: A Measure of Disorder. 2 Entropy and the Clausius Inequality The second law of thermodynamics leads to the definition of a new property called.
Thermodynamics Lecture Series Applied Sciences Education.
The Second Law of Thermodynamics Chapter Introduction The first law of thermodynamics is simple, general, but does not constitute a complete theory.
Evaluating entropy changes
Thermodynamics I Chapter 6 Entropy Mohsin Mohd Sies Fakulti Kejuruteraan Mekanikal, Universiti Teknologi Malaysia.
PTT 201/4 THERMODYNAMIC SEM 1 (2012/2013). Objectives Apply the second law of thermodynamics to processes. Define a new property called entropy to quantify.
Introduction Lecture Prepared by Prof. M. G. Wasel.
Dr.Salwa Al Saleh Lecture 9 Thermodynamic Systems Specific Heat Capacities Zeroth Law First Law.
Q19. Second Law of Thermodynamics
The Laws of Thermodynamics
Review for Exam 2.
Heat Engines and The Carnot Cycle. First Statement of the Second Law of Thermodynamics The first statement of the second law is a statement from common.
The Second Law of Thermodynamics Chapter 6. The Second Law  The second law of thermodynamics states that processes occur in a certain direction, not.
Chapter seven The second Law of thermodynamics The direction of thermal phenomena IF a system for some reason or other is not in a state of equilibrium.
© 2005 Pearson Prentice Hall This work is protected by United States copyright laws and is provided solely for the use of instructors in teaching their.
The Second Law of Thermodynamics
Lecture 5 – The Second Law (Ch. 2)
Entropy Change Property diagrams (T-s and h-s diagrams) from the definition of the entropy, it is known that Q=TdS during a reversible.
Chapter 20 Entropy and the Second Law of Thermodynamics 20.1 Some one-way processes Which is closer to ‘common’ sense? Ink diffusing in a beaker of water.
Entropy, the Second and Third Law of Thermodynamics By Doba Jackson, Ph.D. Associate Professor of Chemistry and Biochemistry Huntingdon College.
Entropy Property Relationships Chapter 7b. The T-ds relations Consider an internally reversible process occurring in a closed system.
CHAPTER 15 Thermodynamics Thermodynamic Systems and Their Surroundings Thermodynamics is the branch of physics that is built upon the fundamental.
Thermodynamics Thermal Processes The 2 nd Law of Thermodynamics Entropy.
Thermodynamics I Inter - Bayamon Lecture 7 Thermodynamics I MECN 4201 Professor: Dr. Omar E. Meza Castillo
6. ENTROPY. Objectives Apply the second law of thermodynamics to processes. Define a new property called entropy to quantify the second-law effects. Establish.
kr 1 Lecture Notes on Thermodynamics 2008 Chapter 7 Entropy Prof. Man Y. Kim, Autumn 2008, ⓒ Aerospace.
CHAPTER 6 Entropy. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. The Clausius Inequality: This inequality.
Chapter 11 Laws of Thermodynamics. Chapter 11 Objectives Internal energy vs heat Work done on or by a system Adiabatic process 1 st Law of Thermodynamics.
Reversible and irreversible processes Physics Entropy 28 September 2011.
Objectives Introduce the thermodynamic property entropy (S) using the Clausius inequality Recognize the fact that the entropy is always increasing for.
ENGR 2213 Thermodynamics F. C. Lai School of Aerospace and Mechanical Engineering University of Oklahoma.
ENGR 2213 Thermodynamics F. C. Lai School of Aerospace and Mechanical Engineering University of Oklahoma.
Entropy (YAC- Ch. 6) Introduce the thermodynamic property called Entropy (S) Entropy is defined using the Clausius inequality Introduce the Increase of.
Chapter 18 Second Law of Thermodynamics. Introduction 2 First law → conservation of energy Processes that conserve energy may not occur 400K300K heat.
Second Law of Thermodynamics Heat generally cannot flow spontaneously from a material at lower temperature to a material at higher temperature. The entropy.
Thermodynamics of Ideal Processes P M V Subbarao Professor Mechanical Engineering Department Entropy View of Theoretical Processes …..
Lecture 7 – The Second Law (Ch. 2)
Chapter 12 Laws of Thermodynamics. Chapter 12 Objectives Internal energy vs heat Work done on or by a system Adiabatic process 1 st Law of Thermodynamics.
First law of thermodynamics l first law of thermodynamics: heat added to a system goes into the internal energy of the system and/or into doing work heat.
Advanced Placement Physics B Chapter 12: Heat Engines and Efficiency.
THE SECOND LAW OF THERMODYNAMICS Entropy. Entropy and the direction of time Microscopically the eqs. of physics are time reversible ie you can turn the.
Dr. Owen Clarkin School of Mechanical & Manufacturing Engineering Summary of Energy Topics Chapter 1: Thermodynamics / Energy Introduction Chapter 2: Systems.
Chapter 7 THE SECOND LAW OF THERMODYNAMICS
The Laws of Thermodynamics
Chapter 3 The 2nd law of thermodynamics
Heat Engines Entropy The Second Law of Thermodynamics
Presentation transcript:

Entropy Change by Heat Transfer Define Thermal Energy Reservoir (TER) –Constant mass, constant volume –No work - Q only form of energy transfer –T uniform and constant

Entropy Change by Heat Transfer Consider two TERs at different Ts, in contact but isolated from surroundings Heat transfer between TERs produces entropy as long as T B >T A

Second Law for Control Mass Mechanical Energy Reservoir (MER) CM interacts with a TER and an MER MER no disorder; provides only reversible work Overall system isolated

2nd Law No entropy change could occur because: - Isentropic process (P s = 0) - entropy production cancelled by heat loss  Ps -  Q/T = 0

Alternative Approach to 2nd Law Clausius It is impossible to design a cyclic device that raises heat from a lower T to a higher T without affecting its surroundings. (need work) Kelvin-Planck It is impossible to design a cyclic device that takes heat from a reservoir and converts it to work only (must have waste heat)

Carnot’s Propositions Corollaries of Clausius and Kelvin- Planck versions of 2nd Law: 1.It is impossible to construct a heat engine that operates between two TERs that has higher thermal efficiency than a reversible heat engine.  th,rev >  th,irrev 2.Reversible engines operating between the same TERs have the same  th,rev

Carnot (Ideal) Cycle Internally reversible Interaction with environment reversible QhQh QLQL W in W out T S Reversible work S - constant Reversible heat transfer T - constant

Carnot efficiency Define efficiency: QHQH QLQL W This is the best one can do

Gibbs Equation State equations relate changes in T.D. variables to each other: e.g.,  q -  w = du If reversible and pdv work only In terms of enthalpy: dh = du + d(pv) dh = du + pdv + vdp; Tds = dh -vdp-pdv+pdv Tds = du + pdv Tds = dh - vdp

Unique aspect of Thermodynamics The Gibbs Equations were derived assuming a reversible process. However, it consists of state variables only; i.e., changes are path independent. Proven for reversible processes but applicable to irreversible processes also.

Enthalpy Relations for a Perfect Gas Show yourself: fn (T)fn (p)

Calculating  s Calculate temperature and pressure effects separately s O (T) values are tabulated for different gases in Tables D

For a Calorically Perfect Gas