- Thermodynamics deals with energy and its transformations. Key concepts introduced include systems, properties, state, equilibrium, processes and cycles.
- Important units and dimensions in the metric (SI) and English systems are discussed. The concept of dimensional homogeneity is emphasized.
- Temperature scales, pressure, atmospheric pressure, and their measurement using instruments such as thermometers, manometers and barometers are described.
- Variations in pressure with depth and its transmission in fluids, as governed by Pascal's law, are explained.
Thermodynamics is the branch of science dealing with heat, work, temperature, and energy. It can be studied from both a macroscopic and microscopic perspective. A system is defined along with its surroundings and boundary. Systems can be open, closed, or isolated depending on what crosses the boundary. Thermodynamic properties are either extensive or intensive, and describe the state of a system. A process is a change in a system's state, and can be reversible or irreversible. Thermodynamic equilibrium requires thermal, mechanical, and chemical equilibrium.
This document provides definitions and concepts related to thermodynamics. It discusses microscopic and macroscopic approaches, defines key terms like system, surroundings, boundary, and state. It classifies thermodynamic systems and properties, and describes concepts like equilibrium, path, process, and cycle. It defines different forms of energy specifically work and heat. It also gives the first law of thermodynamics and discusses other thermodynamic processes.
This document provides an introduction to fundamental concepts in thermodynamics. It defines thermodynamics as the science concerned with energy storage and transformations, mostly involving heat and work. The three main concepts introduced are systems, surroundings, and boundaries. A system is the quantity of matter or region being studied, surroundings are outside the system, and boundaries separate the two. Thermodynamic properties can be intensive, like temperature, or extensive, like energy. Thermodynamic processes involve changes between equilibrium states.
This document provides an introduction to basic thermodynamics concepts. It begins by outlining the objectives of defining key vocabulary, reviewing unit systems, and explaining basic concepts like system, state, equilibrium, process and cycle. It then discusses energy and the first and second laws of thermodynamics. The document also defines properties of systems, intensive vs extensive properties, and concepts like continuum, density, and the state postulate. Finally, it covers processes, cycles, temperature scales, and pressure. The overall aim is to establish foundational thermodynamics concepts.
This document provides an introduction to thermodynamics. It defines thermodynamics as the science dealing with heat, work, and their relation to properties of matter and energy change. The document outlines the four laws of thermodynamics and describes the zeroth law regarding thermal equilibrium, the first law regarding conservation of energy and internal energy, the second law regarding limits on heat conversion and direction of processes, and the third law defining absolute zero entropy. Examples of engineering applications are given in areas like heat engines, refrigeration, and air conditioning. Key concepts discussed include system, surroundings, state, path, process, equilibrium, intensive/extensive properties, and reversible/irreversible processes.
Engineering Thermodynamics-Basic concepts 1Mani Vannan M
Engineering thermodynamics covers basic concepts including:
1) The continuum approach views matter as a continuous substance rather than discrete atoms, allowing properties to vary continuously through space.
2) Macroscopic and microscopic approaches differ in whether properties are averaged or describe individual molecules.
3) Path functions like work and heat depend on process, while point functions like volume depend only on state.
4) Intensive properties are independent of system size, while extensive properties depend on size.
thermodynamics, basic definitions with explanations, heat transfer, mode of heat transfer, Difference between thermodynamics and heat transfer?What is entropy?
Fluid properties like density, viscosity, and specific gravity are important to characterize different fluids. Density is defined as mass per unit volume and determines whether a flow is compressible or incompressible. Viscosity measures a fluid's resistance to flow and internal friction. It is proportional to shear stress and inversely proportional to velocity gradient. Water has a viscosity of 1x10-3 N-s/m2 while air is less viscous at 1.8x10-5 N-s/m2. Specific gravity is the ratio of a fluid's density to that of water and is a dimensionless property.
Thermodynamics is the branch of science dealing with heat, work, temperature, and energy. It can be studied from both a macroscopic and microscopic perspective. A system is defined along with its surroundings and boundary. Systems can be open, closed, or isolated depending on what crosses the boundary. Thermodynamic properties are either extensive or intensive, and describe the state of a system. A process is a change in a system's state, and can be reversible or irreversible. Thermodynamic equilibrium requires thermal, mechanical, and chemical equilibrium.
This document provides definitions and concepts related to thermodynamics. It discusses microscopic and macroscopic approaches, defines key terms like system, surroundings, boundary, and state. It classifies thermodynamic systems and properties, and describes concepts like equilibrium, path, process, and cycle. It defines different forms of energy specifically work and heat. It also gives the first law of thermodynamics and discusses other thermodynamic processes.
This document provides an introduction to fundamental concepts in thermodynamics. It defines thermodynamics as the science concerned with energy storage and transformations, mostly involving heat and work. The three main concepts introduced are systems, surroundings, and boundaries. A system is the quantity of matter or region being studied, surroundings are outside the system, and boundaries separate the two. Thermodynamic properties can be intensive, like temperature, or extensive, like energy. Thermodynamic processes involve changes between equilibrium states.
This document provides an introduction to basic thermodynamics concepts. It begins by outlining the objectives of defining key vocabulary, reviewing unit systems, and explaining basic concepts like system, state, equilibrium, process and cycle. It then discusses energy and the first and second laws of thermodynamics. The document also defines properties of systems, intensive vs extensive properties, and concepts like continuum, density, and the state postulate. Finally, it covers processes, cycles, temperature scales, and pressure. The overall aim is to establish foundational thermodynamics concepts.
This document provides an introduction to thermodynamics. It defines thermodynamics as the science dealing with heat, work, and their relation to properties of matter and energy change. The document outlines the four laws of thermodynamics and describes the zeroth law regarding thermal equilibrium, the first law regarding conservation of energy and internal energy, the second law regarding limits on heat conversion and direction of processes, and the third law defining absolute zero entropy. Examples of engineering applications are given in areas like heat engines, refrigeration, and air conditioning. Key concepts discussed include system, surroundings, state, path, process, equilibrium, intensive/extensive properties, and reversible/irreversible processes.
Engineering Thermodynamics-Basic concepts 1Mani Vannan M
Engineering thermodynamics covers basic concepts including:
1) The continuum approach views matter as a continuous substance rather than discrete atoms, allowing properties to vary continuously through space.
2) Macroscopic and microscopic approaches differ in whether properties are averaged or describe individual molecules.
3) Path functions like work and heat depend on process, while point functions like volume depend only on state.
4) Intensive properties are independent of system size, while extensive properties depend on size.
thermodynamics, basic definitions with explanations, heat transfer, mode of heat transfer, Difference between thermodynamics and heat transfer?What is entropy?
Fluid properties like density, viscosity, and specific gravity are important to characterize different fluids. Density is defined as mass per unit volume and determines whether a flow is compressible or incompressible. Viscosity measures a fluid's resistance to flow and internal friction. It is proportional to shear stress and inversely proportional to velocity gradient. Water has a viscosity of 1x10-3 N-s/m2 while air is less viscous at 1.8x10-5 N-s/m2. Specific gravity is the ratio of a fluid's density to that of water and is a dimensionless property.
Engineering Thermodynamics -Basic Concepts 2 Mani Vannan M
This document provides an overview of basic thermodynamics concepts including:
- Systems, boundaries, surroundings, and the types of thermodynamic systems such as closed, open, isolated, and rigid.
- Thermodynamic states, processes, paths, and cycles along with examples of different processes.
- The basic definitions of heat, work, internal energy, and enthalpy along with the sign conventions.
- The zeroth law of thermodynamics regarding thermal equilibrium and temperature.
- The first law of thermodynamics regarding the relationship between heat, work, and changes in internal energy for closed and open systems.
i hope, it will helpful to the students and peoples in the search of topics mentioned
it is informative to study to even get passing marks or for revision
This document provides an overview of basic concepts in thermodynamics. It discusses the four laws of thermodynamics, the classification of thermodynamics into classical and statistical approaches, and definitions of key terms like system, surroundings, boundary, state, property, process, cycle, and path. The conversion of energy is governed by the first and second laws of thermodynamics, and thermodynamic equilibrium refers to thermal, mechanical, and chemical equilibrium within a system.
This document provides an introduction to engineering thermodynamics for mechanical engineering students. It defines key concepts like system, state, path, process, equilibrium and introduces the three laws of thermodynamics. The first law is the conservation of energy, the second law is the conservation of entropy, and the zeroth law defines thermal equilibrium. It explains the differences between open, closed and isolated systems and discusses properties of state, intensive and extensive properties. Reversible and irreversible processes are also defined. The goal is to provide students the foundation to analyze thermodynamic processes and devices.
This document provides an overview of key topics covered in part two of thermodynamics, including various types of thermodynamic systems and equilibrium, as well as thermodynamic processes. It discusses homogeneous and heterogeneous systems, and describes chemical, mechanical, thermal, and phase equilibrium. The document outlines important thermodynamic processes such as isothermal, adiabatic, isobaric, isochoric, reversible, irreversible, and cyclic processes.
The document discusses thermodynamics from both macroscopic and microscopic viewpoints. It defines key concepts like system, surroundings, open and closed systems, intensive and extensive properties, state, equilibrium, processes, cycles, work, heat transfer, and different types of thermodynamic processes. Specific processes discussed include isobaric, isochoric, isothermal, and polytropic processes. The document also explains the zeroth law of thermodynamics and its importance for temperature measurement.
Understand the physical mechanism of convection and its classification.
Visualize the development of velocity and thermal boundary layers during flow over surfaces.
Gain a working knowledge of the dimensionless Reynolds, Prandtl, and Nusselt numbers.
Distinguish between laminar and turbulent flows, and gain an understanding of the mechanisms of momentum and heat transfer in turbulent flow.
Derive the differential equations that govern convection on the basis of mass, momentum, and energy balances, and solve these equations for some simple cases such as laminar flow over a flat plate.
Non dimensionalize the convection equations and obtain the functional forms of friction and heat transfer coefficients.
Use analogies between momentum and heat transfer, and determine heat transfer coefficient from knowledge of friction coefficient.
The First Law of Thermodynamics states that energy cannot be created or destroyed, only changed in form. It can be expressed as:
ΔU = Q - W, where ΔU is the change in internal energy of a system, Q is heat transferred, and W is work done. For a closed system undergoing a cyclic process, the net heat transfer equals the net work. The First Law has several corollaries including that a perpetual motion machine of the first kind is impossible as it would violate conservation of energy. Joule's experiments demonstrated the equivalence of heat and work. The First Law applies to open systems using a control volume approach where the net rate of energy transfer equals the rate of change of energy within the
This document provides an overview of thermodynamics. It discusses key topics including:
- Thermodynamics relates heat and work and deals with energy imposed on substances. It is based on experimental observations and four laws.
- Thermodynamic systems, processes, equilibrium, properties, units and dimensions are introduced. Microscopic and macroscopic approaches are compared.
- Important concepts like state, phase, intensive/extensive properties, equations of state, and specific volume/density are defined. Common thermodynamic processes like isothermal, isobaric and isochoric are described.
Thermodynamics deals with energy and its transformation between different forms. The first law of thermodynamics states that energy cannot be created or destroyed, only transformed from one form to another. A thermodynamic system exchanges energy in the form of heat or work with its surroundings. Closed systems exchange only energy, while open systems can exchange both energy and matter. Thermodynamic properties like pressure, temperature, and volume are used to describe different thermodynamic processes that occur at either constant values (isobaric, isochoric, isothermal) or with varying values.
In this PPT have have covered
1. Basic thermodynamics definition
2. Thermodynamics law
3. Properties , cycle, Process
4. Derivation of the Process
5.Formula for the numericals.
This topic is use full for those students who want to study basic thermodynamics as a part of their University syllabus.
Most of the university having basic Mechanical engineering as a subject and in this subject Thermodynamics is a topic so by this PPT our aim is to give presentable knowledge of the subject
Lecture 1 introduction of engineering thermodynamicsShevan Sherwany
Here are the key steps to solve this problem using specific volume and pressure:
1. Given: Mass of CO2 = 15 kg
Volume of cylinder = 20 L
2. Calculate specific volume of CO2 using ideal gas law:
v = V/m
v = 20 L / 15 kg = 1.33 m3/kg
3. Use the specific volume to calculate the pressure:
p = mRT/vV
p = (15 kg)(0.0821 kPa⋅m3/kg⋅K)(273 K) / (1.33 m3/kg)(20 L)
p = 101.3 kPa
So in summary,
This document discusses the first law of thermodynamics. It provides:
1) An overview of the first law for closed and open systems, including Joule's experiment that established the law.
2) Key concepts such as the steady flow energy equation, throttling devices, nozzles, and diffusers.
3) Applications of the first law to engineering problems involving fluid flow and energy transfers as work and heat.
To download this lecture notes kindly visit website or contact me
Topics include: visit my website (www.mech-4u.weebly.com)
1) introduction to thermodynamics
2) basics concepts of thermodynamics
3) types of system
4) properties of system
5) zeroth law of thermodynamics
6) concept of heat and work
7) properties of steam
8) properties of ideal gas
This document discusses key concepts in thermodynamics including:
- Thermodynamics is the science concerned with energy storage and transformations within a body.
- A system, its surroundings and boundaries are defined. Systems can be isolated, closed, or open.
- Properties of a system include intensive and extensive properties, and specific properties.
- States, equilibrium, and processes are discussed, along with different types of processes like isobaric, isothermal, isochoric.
This document provides an overview of fluid kinematics, which is the study of fluid motion without considering forces. It discusses key concepts like streamlines, pathlines, and streaklines. It describes Lagrangian and Eulerian methods for describing fluid motion. It also covers various types of fluid flow such as steady/unsteady, laminar/turbulent, compressible/incompressible, and one/two/three-dimensional flow. Important topics like continuity equation, velocity, acceleration, and stream/velocity potential functions are also summarized. The document is intended to outline the syllabus and learning objectives for a course unit on fluid kinematics.
Here are the key steps to derive the expression for heat of reaction at constant pressure:
1) For a chemical reaction occurring at constant pressure, the enthalpy change (ΔH) is equal to the heat absorbed or released by the system (qP).
2) Enthalpy change (ΔH) is defined as the change in internal energy (ΔU) plus the product of pressure (P) and change in volume (ΔV).
ΔH = ΔU + PΔV
3) For a reaction at constant pressure, the volume change (ΔV) is small and pressure remains constant.
4) From the first law of thermodynamics, the change in internal energy (Δ
The document discusses entropy, which is a thermodynamic property that serves as a tool for analyzing engineering devices according to the second law of thermodynamics. Entropy can be viewed as a measure of disorder in a system, with more disorganized systems having higher entropy. The Clausius inequality and definition of entropy using heat transfer and temperature are provided. The principles of entropy change for open and closed systems, as well as the increase of entropy principle and third law of thermodynamics, are summarized.
This document provides an introduction to thermodynamics concepts including:
- Thermodynamics is the science of energy and its transformations. The first and second laws of thermodynamics are introduced.
- Basic concepts such as system, surroundings, state, equilibrium, process, and cycle are defined. Temperature scales, pressure, density, and state postulate are also explained.
- The document outlines the problem solving technique used in thermodynamics and introduces EES software for solving equations.
chapter 4 first law of thermodynamics thermodynamics 1abfisho
This document discusses the first law of thermodynamics for closed systems. It begins by defining the first law as the law of conservation of energy, where energy cannot be created or destroyed, only transformed between states. The energy balance is then analyzed for closed systems, where the internal energy, kinetic energy, potential energy, work and heat transfer across boundaries are considered. Several examples are provided to demonstrate applying the first law to calculate changes in internal energy, work, heat transfer and other properties for closed thermodynamic systems undergoing various processes like constant volume, constant pressure and others.
The document discusses key concepts of the first law of thermodynamics including:
- Energy can change forms but is conserved, neither created nor destroyed.
- The energy balance of a system equals energy entering minus exiting by heat, work, and mass flow.
- Energy transfer occurs through heat, work, and for open systems, mass flow.
- Energy efficiency compares useful energy transferred to total energy supplied.
It provides examples of efficiency calculations for devices like heaters, generators, and pumps. The homework problems reinforce applying the first law to analyze energy transfers and changes within thermodynamic systems.
The document discusses various topics related to energy and energy transfer in thermodynamics:
1. It defines different forms of energy including internal, kinetic, potential, electrical, chemical, and nuclear energy. Internal energy is the sum of microscopic energies of a system.
2. It discusses heat and work as two mechanisms of energy transfer across boundaries of a system. Heat transfer is driven by temperature differences while work requires a force and displacement.
3. It describes different modes of heat transfer as conduction, convection, and radiation. Mechanical forms of work include shaft work, spring work, and electrical work.
4. The first law of thermodynamics and concept of energy balance within a system and
Engineering Thermodynamics -Basic Concepts 2 Mani Vannan M
This document provides an overview of basic thermodynamics concepts including:
- Systems, boundaries, surroundings, and the types of thermodynamic systems such as closed, open, isolated, and rigid.
- Thermodynamic states, processes, paths, and cycles along with examples of different processes.
- The basic definitions of heat, work, internal energy, and enthalpy along with the sign conventions.
- The zeroth law of thermodynamics regarding thermal equilibrium and temperature.
- The first law of thermodynamics regarding the relationship between heat, work, and changes in internal energy for closed and open systems.
i hope, it will helpful to the students and peoples in the search of topics mentioned
it is informative to study to even get passing marks or for revision
This document provides an overview of basic concepts in thermodynamics. It discusses the four laws of thermodynamics, the classification of thermodynamics into classical and statistical approaches, and definitions of key terms like system, surroundings, boundary, state, property, process, cycle, and path. The conversion of energy is governed by the first and second laws of thermodynamics, and thermodynamic equilibrium refers to thermal, mechanical, and chemical equilibrium within a system.
This document provides an introduction to engineering thermodynamics for mechanical engineering students. It defines key concepts like system, state, path, process, equilibrium and introduces the three laws of thermodynamics. The first law is the conservation of energy, the second law is the conservation of entropy, and the zeroth law defines thermal equilibrium. It explains the differences between open, closed and isolated systems and discusses properties of state, intensive and extensive properties. Reversible and irreversible processes are also defined. The goal is to provide students the foundation to analyze thermodynamic processes and devices.
This document provides an overview of key topics covered in part two of thermodynamics, including various types of thermodynamic systems and equilibrium, as well as thermodynamic processes. It discusses homogeneous and heterogeneous systems, and describes chemical, mechanical, thermal, and phase equilibrium. The document outlines important thermodynamic processes such as isothermal, adiabatic, isobaric, isochoric, reversible, irreversible, and cyclic processes.
The document discusses thermodynamics from both macroscopic and microscopic viewpoints. It defines key concepts like system, surroundings, open and closed systems, intensive and extensive properties, state, equilibrium, processes, cycles, work, heat transfer, and different types of thermodynamic processes. Specific processes discussed include isobaric, isochoric, isothermal, and polytropic processes. The document also explains the zeroth law of thermodynamics and its importance for temperature measurement.
Understand the physical mechanism of convection and its classification.
Visualize the development of velocity and thermal boundary layers during flow over surfaces.
Gain a working knowledge of the dimensionless Reynolds, Prandtl, and Nusselt numbers.
Distinguish between laminar and turbulent flows, and gain an understanding of the mechanisms of momentum and heat transfer in turbulent flow.
Derive the differential equations that govern convection on the basis of mass, momentum, and energy balances, and solve these equations for some simple cases such as laminar flow over a flat plate.
Non dimensionalize the convection equations and obtain the functional forms of friction and heat transfer coefficients.
Use analogies between momentum and heat transfer, and determine heat transfer coefficient from knowledge of friction coefficient.
The First Law of Thermodynamics states that energy cannot be created or destroyed, only changed in form. It can be expressed as:
ΔU = Q - W, where ΔU is the change in internal energy of a system, Q is heat transferred, and W is work done. For a closed system undergoing a cyclic process, the net heat transfer equals the net work. The First Law has several corollaries including that a perpetual motion machine of the first kind is impossible as it would violate conservation of energy. Joule's experiments demonstrated the equivalence of heat and work. The First Law applies to open systems using a control volume approach where the net rate of energy transfer equals the rate of change of energy within the
This document provides an overview of thermodynamics. It discusses key topics including:
- Thermodynamics relates heat and work and deals with energy imposed on substances. It is based on experimental observations and four laws.
- Thermodynamic systems, processes, equilibrium, properties, units and dimensions are introduced. Microscopic and macroscopic approaches are compared.
- Important concepts like state, phase, intensive/extensive properties, equations of state, and specific volume/density are defined. Common thermodynamic processes like isothermal, isobaric and isochoric are described.
Thermodynamics deals with energy and its transformation between different forms. The first law of thermodynamics states that energy cannot be created or destroyed, only transformed from one form to another. A thermodynamic system exchanges energy in the form of heat or work with its surroundings. Closed systems exchange only energy, while open systems can exchange both energy and matter. Thermodynamic properties like pressure, temperature, and volume are used to describe different thermodynamic processes that occur at either constant values (isobaric, isochoric, isothermal) or with varying values.
In this PPT have have covered
1. Basic thermodynamics definition
2. Thermodynamics law
3. Properties , cycle, Process
4. Derivation of the Process
5.Formula for the numericals.
This topic is use full for those students who want to study basic thermodynamics as a part of their University syllabus.
Most of the university having basic Mechanical engineering as a subject and in this subject Thermodynamics is a topic so by this PPT our aim is to give presentable knowledge of the subject
Lecture 1 introduction of engineering thermodynamicsShevan Sherwany
Here are the key steps to solve this problem using specific volume and pressure:
1. Given: Mass of CO2 = 15 kg
Volume of cylinder = 20 L
2. Calculate specific volume of CO2 using ideal gas law:
v = V/m
v = 20 L / 15 kg = 1.33 m3/kg
3. Use the specific volume to calculate the pressure:
p = mRT/vV
p = (15 kg)(0.0821 kPa⋅m3/kg⋅K)(273 K) / (1.33 m3/kg)(20 L)
p = 101.3 kPa
So in summary,
This document discusses the first law of thermodynamics. It provides:
1) An overview of the first law for closed and open systems, including Joule's experiment that established the law.
2) Key concepts such as the steady flow energy equation, throttling devices, nozzles, and diffusers.
3) Applications of the first law to engineering problems involving fluid flow and energy transfers as work and heat.
To download this lecture notes kindly visit website or contact me
Topics include: visit my website (www.mech-4u.weebly.com)
1) introduction to thermodynamics
2) basics concepts of thermodynamics
3) types of system
4) properties of system
5) zeroth law of thermodynamics
6) concept of heat and work
7) properties of steam
8) properties of ideal gas
This document discusses key concepts in thermodynamics including:
- Thermodynamics is the science concerned with energy storage and transformations within a body.
- A system, its surroundings and boundaries are defined. Systems can be isolated, closed, or open.
- Properties of a system include intensive and extensive properties, and specific properties.
- States, equilibrium, and processes are discussed, along with different types of processes like isobaric, isothermal, isochoric.
This document provides an overview of fluid kinematics, which is the study of fluid motion without considering forces. It discusses key concepts like streamlines, pathlines, and streaklines. It describes Lagrangian and Eulerian methods for describing fluid motion. It also covers various types of fluid flow such as steady/unsteady, laminar/turbulent, compressible/incompressible, and one/two/three-dimensional flow. Important topics like continuity equation, velocity, acceleration, and stream/velocity potential functions are also summarized. The document is intended to outline the syllabus and learning objectives for a course unit on fluid kinematics.
Here are the key steps to derive the expression for heat of reaction at constant pressure:
1) For a chemical reaction occurring at constant pressure, the enthalpy change (ΔH) is equal to the heat absorbed or released by the system (qP).
2) Enthalpy change (ΔH) is defined as the change in internal energy (ΔU) plus the product of pressure (P) and change in volume (ΔV).
ΔH = ΔU + PΔV
3) For a reaction at constant pressure, the volume change (ΔV) is small and pressure remains constant.
4) From the first law of thermodynamics, the change in internal energy (Δ
The document discusses entropy, which is a thermodynamic property that serves as a tool for analyzing engineering devices according to the second law of thermodynamics. Entropy can be viewed as a measure of disorder in a system, with more disorganized systems having higher entropy. The Clausius inequality and definition of entropy using heat transfer and temperature are provided. The principles of entropy change for open and closed systems, as well as the increase of entropy principle and third law of thermodynamics, are summarized.
This document provides an introduction to thermodynamics concepts including:
- Thermodynamics is the science of energy and its transformations. The first and second laws of thermodynamics are introduced.
- Basic concepts such as system, surroundings, state, equilibrium, process, and cycle are defined. Temperature scales, pressure, density, and state postulate are also explained.
- The document outlines the problem solving technique used in thermodynamics and introduces EES software for solving equations.
chapter 4 first law of thermodynamics thermodynamics 1abfisho
This document discusses the first law of thermodynamics for closed systems. It begins by defining the first law as the law of conservation of energy, where energy cannot be created or destroyed, only transformed between states. The energy balance is then analyzed for closed systems, where the internal energy, kinetic energy, potential energy, work and heat transfer across boundaries are considered. Several examples are provided to demonstrate applying the first law to calculate changes in internal energy, work, heat transfer and other properties for closed thermodynamic systems undergoing various processes like constant volume, constant pressure and others.
The document discusses key concepts of the first law of thermodynamics including:
- Energy can change forms but is conserved, neither created nor destroyed.
- The energy balance of a system equals energy entering minus exiting by heat, work, and mass flow.
- Energy transfer occurs through heat, work, and for open systems, mass flow.
- Energy efficiency compares useful energy transferred to total energy supplied.
It provides examples of efficiency calculations for devices like heaters, generators, and pumps. The homework problems reinforce applying the first law to analyze energy transfers and changes within thermodynamic systems.
The document discusses various topics related to energy and energy transfer in thermodynamics:
1. It defines different forms of energy including internal, kinetic, potential, electrical, chemical, and nuclear energy. Internal energy is the sum of microscopic energies of a system.
2. It discusses heat and work as two mechanisms of energy transfer across boundaries of a system. Heat transfer is driven by temperature differences while work requires a force and displacement.
3. It describes different modes of heat transfer as conduction, convection, and radiation. Mechanical forms of work include shaft work, spring work, and electrical work.
4. The first law of thermodynamics and concept of energy balance within a system and
This document provides an overview of basic thermodynamics concepts including definitions of thermodynamics, thermodynamic systems, properties, processes and cycles. It discusses important thermodynamic concepts such as state, path, reversible and irreversible processes, equilibrium, and measurement of pressure. Examples are given to illustrate compression processes and the use of the Pascal's law for pressure measurement.
Homework assignment #3 in fluid mechanics is due November 24th and contains 12 problems from chapter 8 in the textbook ranging in topics from laminar and turbulent fluid flows to fluid properties and forces. The assignment spans two slides and students are instructed to see the next slide for additional details related to the homework.
This document provides an overview of thermodynamics and related concepts. It defines thermodynamics as the study of energy and its transformation, heat flow, and work potential. Key topics covered include the microscopic and macroscopic approaches to studying thermodynamics, thermodynamic systems and properties, processes like reversible and irreversible processes, and thermodynamic cycles. Dimensional analysis and various thermodynamic units of measurement are also discussed.
The document discusses thermodynamics, dimensions and units, and fundamental concepts of thermodynamics. It defines thermodynamics as the science of energy, and discusses the conservation of energy principle and the first law of thermodynamics. It also defines dimensions as characteristics of physical quantities, and primary and secondary dimensions. Finally, it provides examples of converting between different units for dimensions like length, mass, time, and others.
Melchor J. presented a teaching demo on the first law and of physics. The first law of thermodynamics states that energy cannot be created or destroyed, only changed from one form to another, and the total amount of energy in a system remains constant. It also states that the change in a system's internal energy during a process depends only on the initial and final states, not the path between them.
Bab 1 Thermodynamic of Engineering ApproachIbnu Hasan
This document provides an introduction to basic thermodynamics concepts. It defines thermodynamics as the science of energy and discusses the first and second laws of thermodynamics. The first law states that energy is conserved and can change forms, while the second law says that the quality of energy decreases in actual processes. The document introduces systems, properties, processes, cycles and other foundational topics, providing objectives and definitions for understanding thermodynamics.
This document provides an introduction to basic thermodynamics concepts. It defines thermodynamics as the science of energy, outlines the first and second laws of thermodynamics, and describes systems, properties, processes, cycles, and other foundational topics. Key terms like state, equilibrium, intensive/extensive properties, and temperature scales are precisely defined to establish a framework for further developing thermodynamic principles.
The document discusses basic concepts in thermodynamics including:
- The first law of thermodynamics states that energy is conserved and can change forms but not be created or destroyed.
- The second law asserts that energy has both quantity and quality, and actual processes occur in the direction of decreasing quality of energy.
- A system is a quantity of matter or space chosen for study, it can exchange energy but not mass with its surroundings. A system's properties can be intensive or extensive depending on whether they depend on the system size.
The document provides an overview of thermodynamics concepts including:
- Defining thermodynamics as the science of energy and introducing key concepts like internal energy, the first and second laws of thermodynamics, and applications of thermodynamics.
- Discussing systems, properties, processes, and the importance of units and dimensions.
- Explaining concepts like temperature, pressure, density, state, equilibrium, and different types of systems and processes.
- Introducing problem-solving techniques in thermodynamics including defining the problem, developing a schematic, making assumptions, applying physical laws, and performing calculations.
- Providing an introduction to properties of pure substances and phase change processes
This document provides an overview of key concepts in thermodynamics. It defines thermodynamics as the science of energy and discusses the first and second laws of thermodynamics. The document outlines different types of thermodynamic systems (closed, open, isolated), properties (intensive, extensive), states, equilibrium, and processes (steady flow, quasi-static). It also defines temperature, forms of energy (kinetic, potential, internal), and dimensional analysis. Application areas covered include propulsion, HVAC, computers and various engineering systems.
This document provides an overview of thermodynamics concepts including:
- The four laws of thermodynamics and what they assert about energy and its transformation.
- Systems, surroundings, boundaries, open and closed systems.
- Properties of systems including intensive, extensive, specific properties, and state properties.
- Equilibrium states, processes, cycles, and steady-flow processes.
- Temperature scales including Celsius, Fahrenheit, Kelvin, and Rankine scales.
- Concepts related to pure substances including homogeneous substances, phases, and examples.
This document provides an overview of the ME2320 Thermodynamics I course for Summer I 2016, including the instructor details, syllabus, homework format, and chapter outlines. The first chapter introduces fundamental thermodynamics concepts like systems, properties, processes, the laws of thermodynamics, and temperature and pressure units and scales. It emphasizes developing problem-solving skills through a systematic 7-step technique.
Lecture covering the basic concepts required for the module:
Systems and control volumes
Properties of a system
Density and specific gravity
State and equilibrium
The state postulate
Processes and cycles
The state-flow process
Temperature and the zeroth law of thermodynamics
Temperature scales
Pressure
Variation of pressure with depths
Basis review of thermodynamics_Aircraft PropulsionSuthan Rajendran
This document provides an overview of basic concepts in thermodynamics. It discusses why thermodynamics is important for understanding energy usage in society. It defines key thermodynamic concepts like system, surroundings, boundary, state, property, process, cycle, and equilibrium. It also covers the zeroth law of thermodynamics and defines temperature. The document aims to introduce foundational thermodynamic terms and concepts.
This course provides an introduction to thermodynamics over 15 weeks. Topics covered include the first and second laws of thermodynamics, properties of pure substances, energy analysis of control volumes and cycles, and isentropic processes. By the end of the course, students are expected to understand fundamental thermodynamic principles, laws, and be able to apply concepts such as the first law to calculate work and heat transfer in open and closed systems. Assessment includes exams and problem solving.
This document introduces fundamental concepts in engineering thermodynamics. It defines thermodynamics as the science of energy and discusses how it deals with heat, work, and their effects on temperature and pressure. Systems can be closed, open, or isolated depending on how mass and energy cross their boundaries. The state and properties of a system are described, as well as processes, equilibrium, and steady-flow processes. Common units and dimensions in thermodynamics are outlined. Specific volume, pressure, and temperature are also defined.
The document discusses key concepts in thermodynamics including:
- Systems can be open, closed, or isolated depending on whether work, heat, and mass cross the boundary.
- A system's state is defined by properties like temperature, pressure, and volume. A process occurs as the system moves between states.
- The first law of thermodynamics concerns the conservation of energy as work and heat are applied to a system. The second law concerns entropy.
- Systems must be in thermal, mechanical, and chemical equilibrium for their properties to be well-defined and for reversible processes to occur. Temperature is a measure of thermal equilibrium.
refrigeration and air conditioning(with thermodynamics revision).pptbiniabebe
This document provides an introduction to refrigeration and air conditioning concepts. It discusses that refrigeration removes unwanted heat from an object and transfers it elsewhere, while air conditioning deals with cooling and heating air along with ventilation and filtration. Refrigerators and heat pumps are cyclic devices that use refrigerants to transfer heat from a low temperature medium to a high temperature one. Basic thermodynamic concepts like systems, properties, states, processes, the four laws of thermodynamics, and heat transfer modes of conduction, convection and radiation are reviewed. Phase change processes and property diagrams are also introduced.
Energy cannot be created or destroyed, it can only change forms (first law of thermodynamics). Heat flows in the direction of decreasing temperature (second law of thermodynamics). Thermodynamics is the study of energy and how it transfers between systems and their surroundings. A system is a quantity of matter selected for study, while surroundings are what is outside the system boundary.
This slide will completely describes you about thermodynamics. The basics of thermo is explained in this slide. Intensive and Extensive Propeties are exolained in this properties.
This document defines key concepts in applied chemistry including:
- States are defined by fixed properties throughout a system not undergoing change. Equilibrium occurs when no driving forces act within a system.
- Processes involve changes between equilibrium states, defined by initial and final states and interactions. Examples include isothermal, isobaric, and isochoric processes.
- Steady-flow processes involve continuous, unchanging fluid flow through a control volume like in turbines and heat exchangers.
- The zeroth law of thermodynamics states that two bodies in thermal equilibrium with a third are in equilibrium with each other, allowing thermometers to indicate equilibrium.
- Pressure definitions include absolute, g
This document provides definitions and concepts related to physical chemistry and thermodynamics. It begins with an introduction to physical chemistry and its goal of understanding material systems. It then defines key concepts such as macroscopic and microscopic systems, state variables, state functions, and path functions. The document also defines work, heat, processes, and reservoirs. It introduces gas laws such as the ideal gas law and discusses real gases, their behavior compared to ideal gases, and equations of state like the van der Waals equation. It concludes by defining terms like compressibility factor which account for deviations of real gases from ideal gas behavior.
Unit 1 thermodynamics by varun pratap singh (2020-21 Session)Varun Pratap Singh
Free Download Link (Copy URL):
https://sites.google.com/view/varunpratapsingh/teaching-engagements
Dear Students,
Please find the Basic Mechanical Engineering (TME-101, 2020-21 Session) Unit One notes in this section.
Topic cover in this section are:
UNIT-1: Fundamental Concepts and Definitions
Definition of thermodynamics, System, Surrounding and universe, Phase, Concept of continuum, Macroscopic & microscopic point of view. Density, Specific volume, Pressure, temperature. Thermodynamic equilibrium, Property, State, Path, Process, Cyclic and non-cyclic processes, Reversible and irreversible processes, Quasi-static process, Energy and its forms, Enthalpy.
1) The document discusses the key concepts and objectives of conduction heat transfer including understanding the basic mechanisms of heat transfer such as conduction, convection, and radiation.
2) It explains the differences between thermodynamics, which deals with the amount of heat transfer between equilibrium states, and heat transfer which determines the rates of energy transfers.
3) The three modes of heat transfer - conduction, convection and radiation - are defined and the governing equations for each are provided including Fourier's law of conduction, Newton's law of cooling, and Stefan-Boltzmann law of radiation.
This homework assignment contains 18 problems from chapter 6 that are due on April 17. The problems include 6.4C, 6.10C, 6.13C, 6.21, 6.23, 6.32C, 6.40, 6.50, 6.57, 6.80E, 6.81E, 6.90C, 6.96, 6.97, 6.99, 6.109, and 6.138.
Homework #5 from an unknown course is due on Tuesday, April 8. The homework consists of solving 13 problems from the textbook, including problems 5.8, 5.17, 5.24, 5.30, 5.42, 5.49, 5.56, 5.71E, 5.75, 5.90, 5.114, and 5.155.
This document discusses mass and energy analysis of control volumes for steady-flow engineering devices. It covers topics like nozzles, diffusers, turbines, compressors, throttling valves, mixing chambers, heat exchangers, and pipe/duct flow. Examples are provided for analyzing the energy and mass balances of these systems using the first law of thermodynamics. The document concludes with assigning homework problems involving these thermodynamic concepts.
This document provides an overview of chapter 5 of a thermodynamics textbook, which covers mass and energy analysis of control volumes. The key objectives are to develop the conservation of mass and first law of thermodynamics as applied to control volumes. It defines concepts like mass flow rate, volume flow rate, enthalpy, and flow work. Examples are provided to demonstrate applying conservation of mass to problems involving steady and unsteady flow systems as well as compressible and incompressible fluids. The chapter also discusses applying the energy balance to steady flow systems like nozzles, compressors, and heat exchangers.
This document discusses thermodynamic properties of pure substances. It introduces pure substances and their phases of solid, liquid, and gas. Phase change processes are described, including saturated liquid, vapor, and superheated regions. T-V, P-V, and P-T diagrams are presented to illustrate the relationships between these properties. Key concepts covered include saturation temperature/pressure, latent heats of fusion and vaporization, the p-v-T surface, and how substances' behaviors differ when expanding or contracting during phase changes. Objectives are listed for understanding pure substance thermodynamics and properties.
1) The document discusses properties of pure substances and how they are presented in tables. It focuses on water properties and steam tables.
2) It explains different phases like saturated liquid, saturated vapor, superheated vapor, and compressed liquid. It also discusses quality and using tables to find properties through interpolation.
3) The ideal gas equation of state is presented along with when it can be applied to water vapor. The compressibility factor is introduced as a measure of how gases deviate from ideal behavior.
Thermodynamics I discusses energy analysis of closed systems. It examines moving boundary work from processes like in engines and compressors. The first law of thermodynamics states the principle of conservation of energy for closed systems. The general energy balance applied to closed systems relates the change in internal energy to heat and work. Specific heats at constant volume and pressure are defined and used to calculate changes in internal energy and enthalpy for ideal gases and incompressible substances.
This document discusses energy analysis of closed systems, including specific heats at constant volume and pressure, internal energy, enthalpy, and specific heats of ideal gases and incompressible substances like solids and liquids. It provides equations relating these concepts and explains how to calculate changes in internal energy and enthalpy using data tables, functional forms of specific heats, or average specific heat values. Examples are also included.
This homework assignment contains 14 math problems from chapter 4 that are due on Thursday, March 27. The problems include 4.5E, 4.8, 4.24, 4.25, 4.34, 4.42, 4.46, 4.55, 4.59E, 4.70E, 4.74, 4.81, and 4.89 from the textbook.
Homework #3 from an unknown course is due on Thursday, March 6. It consists of solving 13 problems from Chapter 3: problems 3.13C, 3.15C, 3.20C, 3.28, 3.37E, 3.42, 3.44, 3.57, 3.61, 3.78, 3.81, 3.89, and 3.93.
Homework #3 from an unknown course is due on Thursday, March 6. It consists of solving 13 problems from Chapter 3 of the textbook, ranging from problems 3.13C through 3.93. Students are to complete problems 3.13C, 3.15C, 3.20C, 3.28, 3.37E, 3.42, 3.44, 3.57, 3.61, 3.78, 3.81, 3.89, and 3.93.
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Chapter wise All Notes of First year Basic Civil Engineering.pptxDenish Jangid
Chapter wise All Notes of First year Basic Civil Engineering
Syllabus
Chapter-1
Introduction to objective, scope and outcome the subject
Chapter 2
Introduction: Scope and Specialization of Civil Engineering, Role of civil Engineer in Society, Impact of infrastructural development on economy of country.
Chapter 3
Surveying: Object Principles & Types of Surveying; Site Plans, Plans & Maps; Scales & Unit of different Measurements.
Linear Measurements: Instruments used. Linear Measurement by Tape, Ranging out Survey Lines and overcoming Obstructions; Measurements on sloping ground; Tape corrections, conventional symbols. Angular Measurements: Instruments used; Introduction to Compass Surveying, Bearings and Longitude & Latitude of a Line, Introduction to total station.
Levelling: Instrument used Object of levelling, Methods of levelling in brief, and Contour maps.
Chapter 4
Buildings: Selection of site for Buildings, Layout of Building Plan, Types of buildings, Plinth area, carpet area, floor space index, Introduction to building byelaws, concept of sun light & ventilation. Components of Buildings & their functions, Basic concept of R.C.C., Introduction to types of foundation
Chapter 5
Transportation: Introduction to Transportation Engineering; Traffic and Road Safety: Types and Characteristics of Various Modes of Transportation; Various Road Traffic Signs, Causes of Accidents and Road Safety Measures.
Chapter 6
Environmental Engineering: Environmental Pollution, Environmental Acts and Regulations, Functional Concepts of Ecology, Basics of Species, Biodiversity, Ecosystem, Hydrological Cycle; Chemical Cycles: Carbon, Nitrogen & Phosphorus; Energy Flow in Ecosystems.
Water Pollution: Water Quality standards, Introduction to Treatment & Disposal of Waste Water. Reuse and Saving of Water, Rain Water Harvesting. Solid Waste Management: Classification of Solid Waste, Collection, Transportation and Disposal of Solid. Recycling of Solid Waste: Energy Recovery, Sanitary Landfill, On-Site Sanitation. Air & Noise Pollution: Primary and Secondary air pollutants, Harmful effects of Air Pollution, Control of Air Pollution. . Noise Pollution Harmful Effects of noise pollution, control of noise pollution, Global warming & Climate Change, Ozone depletion, Greenhouse effect
Text Books:
1. Palancharmy, Basic Civil Engineering, McGraw Hill publishers.
2. Satheesh Gopi, Basic Civil Engineering, Pearson Publishers.
3. Ketki Rangwala Dalal, Essentials of Civil Engineering, Charotar Publishing House.
4. BCP, Surveying volume 1
Communicating effectively and consistently with students can help them feel at ease during their learning experience and provide the instructor with a communication trail to track the course's progress. This workshop will take you through constructing an engaging course container to facilitate effective communication.
2. Objectives
• Identify the unique vocabulary associated with
thermodynamics through the precise definition of
basic concepts to form a sound foundation for the
development of the principles of thermodynamics.
• Review the metric SI and the English unit systems.
• Explain the basic concepts of thermodynamics such
as system, state, state
postulate, equilibrium, process, and cycle.
• Review concepts of temperature, temperature
scales, pressure, and absolute and gage pressure.
2
3. THERMODYNAMICS AND ENERGY
• Thermodynamics: The science of
energy.
• Energy: The ability to cause changes.
• The name thermodynamics stems from
the Greek words therme (heat) and
dynamis (power).
• Conservation of energy principle:
During an interaction, energy can change
from one form to another but the total
amount of energy remains constant.
• Energy cannot be created or destroyed.
• The first law of thermodynamics: An
expression of the conservation of energy
principle.
• The first law asserts that energy is a
thermodynamic property.
Energy cannot be created
or destroyed; it can only
change forms (the first law).
3
4. • The second law of thermodynamics:
It asserts that energy has quality as
well as quantity, and actual processes
occur in the direction of decreasing
quality of energy.
• Classical thermodynamics: A
macroscopic approach to the study of
thermodynamics that does not require
a knowledge of the behavior of
individual particles.
Conservation of energy
principle for the human body.
• It provides a direct and easy way to the
solution of engineering problems and it
is used in this text.
• Statistical thermodynamics: A
microscopic approach, based on the
behavior of individual particles.
Heat flows in the direction of
decreasing temperature.
4
5. IMPORTANCE OF DIMENSIONS AND UNITS
• Any physical quantity can be characterized by dimensions.
• The magnitudes assigned to the dimensions are called units.
• Some basic dimensions such as mass m, length L, time t, and
temperature T are selected as primary or fundamental
dimensions, while others such as velocity V, energy E, and volume V
are expressed in terms of the primary dimensions and are called
secondary dimensions, or derived dimensions.
• Unit systems:
Metric (SI) system:
English system:
5
6. W weight
m mass
g gravitational
acceleration
A body weighing
60 kgf on earth
will weigh only 10
kgf on the moon.
The relative magnitudes of the force
units newton (N), kilogram-force
(kgf), and pound-force (lbf).
The weight of a unit
mass at sea level.
6
7. Dimensional homogeneity
All equations must be dimensionally homogeneous.
To be dimensionally homogeneous, all the terms in an equation must have the same
unit.
Unity Conversion Ratios
All nonprimary units (secondary units) can be formed by combinations of primary
units.
Force units, for example, can be expressed as
They can also be expressed more conveniently as unity conversion ratios as
Unity conversion ratios are identically equal to 1 and are unitless, and thus
such ratios (or their inverses) can be inserted conveniently into any calculation
to properly convert units.
7
8. Example
Discuss Example 1-3 in class:
Using unity conversion ratios, show that 1.00 lbm weighs 1.00 lbf on earth.
8
9. CLOSED SYSTEMS AND CONTROL VOLUMES
• System: A quantity of matter or a region
in space chosen for study.
• Surroundings: The mass or region
outside the system
• Boundary: The real or imaginary surface
that separates the system from its
surroundings.
• The boundary of a system can be fixed or
movable.
• Systems may be considered to be closed
or open.
• Closed system
(Control mass):
A fixed amount
of mass, and no
mass can cross
its boundary.
9
10. • Open system (control volume): A properly
selected region in space.
• It usually encloses a device that involves
mass flow such as a compressor, turbine, or
nozzle.
• Both mass and energy can cross the
boundary of a control volume.
• Control surface: The boundaries of a control
volume. It can be real or imaginary.
An open system (a
control volume) with one
inlet and one exit.
10
11. PROPERTIES
OF A SYSTEM
• Property: Any characteristic of a
system.
• Some familiar properties are
pressure P, temperature T, volume
V, and mass m.
• Properties are considered to be
either intensive or extensive.
• Intensive properties: Those that
are independent of the mass of a
system, such as
temperature, pressure, and density.
• Extensive properties: Those
whose values depend on the size—
or extent—of the system.
Criterion to differentiate intensive
• Specific properties: Extensive
and extensive properties.
properties per unit mass.
11
12. Continuum
•
•
•
•
•
Matter is made up of atoms that are
widely spaced in the gas phase. Yet
it is very convenient to disregard the
atomic nature of a substance and
view it as a
continuous, homogeneous matter
with no holes, that is, a continuum.
The continuum idealization allows us
to treat properties as point functions
and to assume the properties vary
continually in space with no jump
discontinuities.
This idealization is valid as long as
the size of the system we deal with
is large relative to the space
between the molecules.
This is the case in practically all
problems.
In this text we will limit our
consideration to substances that can
be modeled as a continuum.
Despite the large gaps between
molecules, a substance can be treated as
a continuum because of the very large
number of molecules even in an
extremely small volume.
12
13. DENSITY AND SPECIFIC GRAVITY
Density
Specific volume
Specific gravity: The ratio
of the density of a
substance to the density of
some standard substance
at a specified temperature
(usually water at 4°C).
Specific weight: The
weight of a unit volume
of a substance.
Density is
mass per unit
volume;
specific volume
is volume per
unit mass.
13
14. STATE AND EQUILIBRIUM
•
•
•
•
•
Thermodynamics deals with equilibrium states.
Equilibrium: A state of balance.
In an equilibrium state there are no unbalanced potentials (or driving forces)
within the system.
Thermal equilibrium: If the temperature is the same throughout the entire
system.
Mechanical equilibrium: If there is no change in pressure at any point of the
system with time.
•
Phase equilibrium: If a system
involves two phases and when the
mass of each phase reaches an
equilibrium level and stays there.
•
Chemical equilibrium: If the
chemical composition of a system
does not change with time, that
is, no chemical reactions occur.
A closed system reaching thermal
equilibrium.
14
15. The State Postulate
• The number of properties
required to fix the state of a
system is given by the state
postulate:
The state of a simple
compressible system is
completely specified by
two
independent, intensive
properties.
• Simple compressible
system: If a system involves
no
electrical, magnetic, gravitati
onal, motion, and surface
tension effects.
A system at two different states.
The state of nitrogen is fixed by two
independent, intensive properties.
15
16. PROCESSES AND CYCLES
Process: Any change that a system undergoes from one equilibrium state to
another.
Path: The series of states through which a system passes during a process.
To describe a process completely, one should specify the initial and final
states, as well as the path it follows, and the interactions with the
surroundings.
Quasistatic or quasi-equilibrium process: When a process proceeds in such
a manner that the system remains infinitesimally close to an equilibrium state
at all times.
16
17. •
•
•
•
•
•
•
Process diagrams plotted by
employing thermodynamic properties
as coordinates are very useful in
visualizing the processes.
Some common properties that are
used as coordinates are temperature
T, pressure P, and volume V (or
specific volume v).
The prefix iso- is often used to
designate a process for which a
particular property remains constant.
Isothermal process: A process
during which the temperature T
remains constant.
Isobaric process: A process during
which the pressure P remains
constant.
Isochoric process: A process during
which the specific volume v remains
constant.
Cycle: A process during which the
initial and final states are identical.
The P-V diagram of a compression
process.
17
18. The Steady-Flow Process
•
•
•
•
The term steady implies no
change with time. The
opposite of steady is
unsteady, or transient.
A large number of
engineering devices operate
for long periods of time
under the same
conditions, and they are
classified as steady-flow
devices.
Steady-flow process: A
process during which a fluid
flows through a control
volume steadily.
Steady-flow conditions can
be closely approximated by
devices that are intended for
continuous operation such
as
turbines, pumps, boilers, co
ndensers, and heat
exchangers or power plants
During a steadyflow process, fluid
properties within
the control
volume may
change with
position but not
with time.
Under steady-flow conditions, the mass
and energy contents of a control volume
remain constant.
18
19. TEMPERATURE AND THE ZEROTH LAW OF
THERMODYNAMICS
• The zeroth law of thermodynamics: If two bodies are in thermal
equilibrium with a third body, they are also in thermal equilibrium with
each other.
• By replacing the third body with a thermometer, the zeroth law can
be restated as two bodies are in thermal equilibrium if both have the
same temperature reading even if they are not in contact.
Two bodies reaching
thermal equilibrium
after being brought
into contact in an
isolated enclosure.
19
20. Temperature Scales
•
•
•
•
•
All temperature scales are based on some easily
reproducible states such as the freezing and boiling
points of water: the ice point and the steam point.
Ice point: A mixture of ice and water that is in equilibrium
with air saturated with vapor at 1 atm pressure (0°C or
32°F).
Steam point: A mixture of liquid water and water vapor
(with no air) in equilibrium at 1 atm pressure (100°C or
212°F).
Celsius and Kelvin scales: in SI unit system
Fahrenheit and Rankine scales: in English unit system
• Celsius and Fahrenheit:
relative units
• Kelvin and Rankine:
absolute units
Comparison of
temperature scales.
Comparison of magnitudes of various
temperature units.
20
21. Example
Discuss Example 1-4 in class:
During a heating process, the temperature of a system rises by 10 C.
Express this rise in temperature in K, F, and R.
21
22. PRESSURE
68 kg
136 kg
Pressure: A normal force exerted
by a fluid per unit area
Afeet=300cm2
1 psi = 1 lbf/in2 = 6894.8 Pa
0.23 kgf/cm2
0.46 kgf/cm2
P=68/300=0.23 kgf/cm2
The normal stress (or “pressure”) on the
feet of a chubby person is much greater
than on the feet of a slim person.
Some
basic
pressure
gages.
22
23. • Absolute pressure: The actual pressure at a given position. It is
measured relative to absolute vacuum (i.e., absolute zero pressure).
• Gage pressure: The difference between the absolute pressure and
the local atmospheric pressure. Most pressure-measuring devices are
calibrated to read zero in the atmosphere, and so they indicate gage
pressure.
• Vacuum pressures: Pressures below atmospheric pressure.
Throughout
this text, the
pressure P
will denote
absolute
pressure
unless
specified
otherwise.
23
24. Example
Discuss Example 1-5 in class:
A vacuum gage connected to a chamber reads 5.8 psi at a location where
the atmospheric pressure is 14.5 psi. Determine the absolute pressure in the
chamber.
24
25. Variation of Pressure with Depth
When the variation of density
with elevation is known
Free-body diagram of a rectangular
fluid element in equilibrium.
If ρ = const.
The pressure of a fluid at rest
increases with depth (as a result of added weight).
25
26. In a room filled with
a gas, the variation
of pressure with
height is negligible.
Pressure in a liquid
at rest increases
linearly with
distance from the
free surface.
The pressure is the
same at all points on
a horizontal plane in
a given fluid
regardless of
geometry, provided
that the points are
interconnected by
the same fluid.
26
27. Pascal’s law: The pressure applied to a confined fluid increases the
pressure throughout by the same amount.
in other words
A change in pressure at any point in an enclosed fluid at rest is
transmitted undiminished to all points in the fluid
The area ratio A2/A1 is
called the ideal mechanical
advantage of the hydraulic
lift.
Lifting of a large weight by a
small force by the application
of Pascal’s law.
27
28. The Manometer
It is commonly used to measure small and
moderate pressure differences. A manometer
contains one or more fluids such as
mercury, water, alcohol, or oil.
Measuring the
pressure drop across
a flow section or a flow
device by a differential
manometer.
The basic
manometer.
In stacked-up fluid layers, the
pressure change across a fluid layer
of density and height h is gh.
28
29. Example
Discuss Example 1-6 in class:
A manometer is used to measure the pressure in a tank. The fluid used
has a specific gravity of 0.85, and the manometer column height is 55
cm, as shown in the figure. If the local atmospheric pressure is 96 kPa,
determine the absolute pressure within the tank.
29
30. THE BAROMETER AND ATMOSPHERIC PRESSURE
•
Atmospheric pressure is measured by a device called a barometer; thus, the
atmospheric pressure is often referred to as the barometric pressure.
•
A frequently used pressure unit is the standard atmosphere, which is defined as
the pressure produced by a column of mercury 760 mm in height at 0°C (Hg =
13,595 kg/m3) under standard gravitational acceleration (g = 9.807 m/s2).
The basic barometer.
The length or the
cross-sectional area
of the tube has no
effect on the height
of the fluid column of
a
barometer, provided
that the tube
diameter is large
enough to avoid
surface tension
(capillary) effects.
30
33. Summary
•
•
Thermodynamics and energy
Importance of dimensions and units
Some SI and English units, Dimensional
homogeneity, Unity conversion ratios
•
•
•
•
Systems and control volumes
Properties of a system
Density and specific gravity
State and equilibrium
The state postulate
•
Processes and cycles
The steady-flow process
•
Temperature and the zeroth law of thermodynamics
Temperature scales
•
Pressure
Variation of pressure with depth
•
The manometer and the atmospheric pressure
33