Thermodynamics Part-01

Thermodynamics: Thermodynamics the results of man's constant effort in converting heat into work. Developed within the nineteenth century largely thanks to Joule, Clausius, Kelvin and Carnor and later its scope was broadened by Gibbs.

Or, 

Thermodynamics is the science that deals with the conversion of heat into energy. It's based upon observations of common experience, which are formulated into thermodynamic laws. 

So we are able to say that 

01. Thermodynamics could be a science managing energy and its transformation. 

02. It deals with equilibrium and feasibility of a process.

03. It also deals with relations between heat and work and therefore the properties of a system. 

What is the importance of thermodynamics? 

The main task of an engineer is to make sure optimum use of the resources-space, lime, energy and matter. Therefore, an engineer deals with the look and development of latest processes and with the development of the prevailing processes. Before undertaking a rich project, an engineer must know the answers to the subsequent sorts of questions. 

• Is that the proposed reaction or physical process possible? 

• Does the reaction process move to completion or does it proceed to a particular extent only beyond which it cannot proceed?

• What factors govern the extent of reaction or equilibrium? 

• What proportion energy is required for the method to require place?

• What's the utmost efficiency of a engine or the most coefficient of performance of a refrigerator? 

Thermodynamics provides answers to the above sorts of questions.

System: A quantity of matter (which is enclosed by a boundary that separates it from the remainder of the universe) on which we focus our attention for thermodynamic analysis is named a thermodynamic system. 

Or, 

In scientific analysis it's essential to obviously identify the topic matter of study on which we focus our attention. In mechanics, an element of the body is isolated from the remainder of the universe and that we draw a free body diagram and analyze the motion by applying Newton's laws of motion. Similarly, in thermodynamics also we identify the topic of study by term thermodynamics system or system for simplicity to specify the matter on which we focus our attention.

Or,

A system may be a quantity of matter bounded by some surface which separates it from the remainder of the world. The boundary surface could also be real or imaginary. it should change in shape and size. A system could also be very simple sort of a gas contained in a cylinder or it's going to be complex sort of a thermal station. the selection of a system may differ from the person performing the analysis. Sometimes the system is additionally spoken as control mass.

                               

Surroundings: All matter external to the system is named surroundings.

Or,

The combination of matter and space external to the system constitutes the environment. For all practical purposes, that a part of the environment where the consequences because of interaction between a system and its surroundings don't seem to be detectable and wish not be considered. A system can exchange energy within the sort of work and warmth with its surroundings. A system which is enclosed by an adiabatic boundary cannot exchange energy as heat with its -surroundings.

Universe: A combination of system and surroundings is termed universe. 

The important characteristics of a system are: 

1. A system contains a certain quantity of matter. This quantity doesn't undergo any change because the system undergoes a process. Therefore, a system is sometimes called Control mass. 

2. The boundary enclosing the system could also be real (for example the glass wall of a thermos bottle acts as a boundary for enclosing coffee (system) contained within the flask) or imaginary (for example one may focus his attention on air contained in Im x 1m x Im space of a room)

3. The system boundary is also rigid or may change its shape, further as in size during a given process. that's the degree of a system may undergo a change. 

4. The system may exchange energy either within the style of work or heat or both, with its surroundings or with other systems. If a system doesn't exchange energy, within the type of work moreover as heat, with its surroundings it is called an isolated system. 

5. A system is also very simple, sort of a certain quantity of coffee held during a thermos flask or it's going to be complex sort of a huge petrochemical plant. 

6. The selection of a system isn't unique and it depends on the analyst .

Classification of System:

01.Closed system
02.Open system
03.Isolated System

01.Open system- An open system is defined as a system within which mass is permitted to cross the system boundary in either direction (from the system to surroundings or vice versa). In analysing open systems, we typically examine a specified region of space, and observe what happens at the boundaries of that region. Most of the engineering devices are open systems. 

                                

02.Closed system - A closed system is commonly defined as a system within which no mass is permitted to cross the system boundary i.e. we'd always consider a system of constant mass.We do permit heat and work to enter or leave but not mass. 

                                 

03.Isolated System - An isolated system is additionally a system within which there's not any interaction between system and also the environment. it's of fixed mass and energy, and hence there's not any mass and energy transfer across the system boundary.