This document provides an overview of basic thermodynamic concepts and definitions for mechanical engineering students. It defines thermodynamics as the branch of science dealing with heat and energy interactions. It discusses microscopic and macroscopic views, types of systems (open, closed, isolated), thermodynamic properties (extensive, intensive, point functions, path functions), processes (reversible, irreversible, cycles), and conditions for thermodynamic equilibrium. The document is intended to introduce students to fundamental thermodynamic concepts.

1. Sanjivani Rural Education Society’s
Sanjivani College of Engineering, Kopargaon-423 603
(An Autonomous Institute, Affiliated to Savitribai Phule Pune University, Pune)
NAAC ‘A’ Grade Accredited, ISO 9001:2015 Certified
Department of Mechanical Engineering
Apura. A. Kulkarni
Assistant Professor
E-mail : kulkarniapurvamech@sanjivani.org.in
Contact No: 9975295187
Subject :- Basic Thermodynamics
S.E Mechanical
Unit 1- Thermodynamic Concepts and Basic Definitions

2. Contents
 What is Thermodynamics?
 Microscopic and Macroscopic
 Types Of Systems
 Thermodynamic Properties
 Point Function and Path Function
 Thermodynamic Equilibrium
A.A.Kulkarni Department Of Mechanical Engineering, Sanjivani COE, Kopargaon 2

3. What is Thermodynamics?
 Thermo means Heat
 Dynamics means motion under the action of force
 Thermodynamics is the branch of science dealing with heat or work
(Broadly energy interaction) and related changes in the physical
properties of substance.
A.A.Kulkarni Department Of Mechanical Engineering, Sanjivani COE, Kopargaon 3

4. Macroscopic VS Micrroscopic
Department Of Mechanical Engineering, Sanjivani COE, Kopargaon A.A. Kulkarni

5. System-It is a region or space for study
Surrounding-Everything external to the
system is surrounding
Universe-System and surrounding together
constitute Universe.
Boundary-System and surrounding is
separated by Boundary.
Boundary can be 1.Fixed(gas inside a rigid
box)2.Movable (piston cylinder arrangement)
Department Of Mechanical Engineering, Sanjivani COE, Kopargaon A.A. kulkarni

6. Types Of System
Department Of Mechanical Engineering, Sanjivani COE, Kopargaon A.A. Kulkarni
• Only energy can
cross the boundary
• e.g.
Refrigerator, AC
Closed system
• No transfer of
energy and matter
across the
boundary
• e.g.
Thermo flask, universe
Isolated
system

7. Thermodynamic Properties
Properties are used to define the characteristics of a system.
E.g. Pressure , Temperature, volume, mass
Thermodynamics properties are mainly divided
into 2 classes
1.Extensive Properties-Properties are dependent on mass . e.g.
volume, energy, enthalpy
2.Intensive Properties-Properties are independent
of mass . e.g. Pressure, Temperature , density
All specific properties are intensive properties.
Department Of Mechanical Engineering, Sanjivani COE, Kopargaon A.A. Kulkarni

8. Thermodynamic Properties
 States-conditions of a system described by its properties
 Process-when system changes from one state to another then
It is called a Process.
 Reversible Process-A process when reversed does not leave
any effect on system and surrounding or it can goes back to
its original state.
 Irreversible Process-A process which cannot be reversed to
its original state
 Cycle-Sequence of different processes whose initial and final
states are same.
Department Of Mechanical Engineering, Sanjivani COE, Kopargaon A.A. Kulkarni

9. Difference Between Point & PathFunction
Department Of Mechanical Engineering, Sanjivani COE, Kopargaon A.A.Kulkarni
• Properties whose value depends
on end states
• exact or perfect differentials
• e.g. Pressure, Temperature ,
Volume
Point function
• Properties whose value depend
on path
• Inexact differentials
• e.g. Work , Heat
Path function

10. Thermodynamic Equilibrium
 A system is said to be in thermodynamic equilibrium if it
satisfies the following three conditions
1. Thermal Equilibrium-No temperature difference between
system and surrounding
2. Mechanical equilibrium-no unbalanced forces within the
system or with the surrounding
3. Chemical equilibrium-no chemical reaction and no change in
chemical composition
Department Of Mechanical Engineering, Sanjivani COE, Kopargaon A.A. Kulkarni

11. •Thank You!
Department Of Mechanical Engineering, Sanjivani COE, Kopargaon P.A. Bojage