Irreversibility and the second law of thermodynamics. The first law places no restriction on the direction of a process, and satisfying the first law. The second law of thermodynamics 1 the second law of thermodynamics 2 no transcript 3 no transcript 4. The second law of thermodynamics is commonly referred to as the law of entropy, and it holds that energy becomes less usable over time. The first, second, and third law of thermodynamics thlaws05. While quantity remains the same first law, the quality of matterenergy deteriorates gradually over time. Basic thermodynamics nptel online videos, courses iit video lectures. Usable energy is inevitably used for productivity, growth and repair. Joules law leads to an important conclusion concerning the internal energy of an ideal gas. Theres about 10 different ways to state it, which is one reason why its weird. Nov 07, 20 hindi second law of thermodynamics l heat engine l heat pump l refrigerator l gate 2018 mechanical duration. Advanced metallurgical thermodynamics nptel online videos. May 22, 2015 the second law of thermodynamics says, in simple terms, entropy always increases. The second law of thermodynamics for the free expansion, we have.
Introduce and define thermodynamic properties such as internal energy and enthalpy. There are several ways in which the second law of thermodynamics can be stated. Jun 12, 2014 obviously we dont encounter such a system in nature and to explain this and similar observations, thermodynamicists proposed a second law of thermodynamics. Basic thermodynamics nptel online videos, courses iit. Basic terms in thermodynamics laws of thermodynamics and thermodynamic. Lec1 introduction and fundamental concepts youtube. If a gas neither does external work nor takes in or gives out heat, dq 0 and dw 0, so that, by the first law of thermodynamics, du 0. Discuss the importance of second law of thermodynamics. The second law of thermodynamics and carnots engine overview. The second law of thermodynamics is a physical law that is not symmetric to reversal of the time direction. The second law of thermodynamics states that processes occur in a certain direction, not in just any direction. The second part covers physical behaviour of a mixture of ideal gases, psychrometry, thermodynamics of reacting systems, combustion, phase and. There are four laws of thermodynamics, they are zeroth law of thermodynamics first law of thermodynamics second law of thermodynamics third law of thermodynamics zeroth law of thermodynamics.
The first law of thermodynamics is a version of the law of conservation of energy, adapted for thermodynamic systems. Limitation of first law the first law of thermodynamic states that a certain energy flow takes place when a system undergoes a process or change of state is possible or not. The second law of thermodynamics is a general principle which places constraints upon the direction of heat transfer and the attainable efficiencies of heat engines. Lecture series on applied thermodynamics for marine systems by prof. Property relationships for pure substances and mixtures, thermodynamic relations, ideal gas mixtures, combustion thermodynamics, gas power cycles, vapour power cycles, refrigeration cycles, reciprocating compressors, compressible flows and steam nozzles. This allowed watt to assess the effectiveness of developments.
Lec12 second law and available energyiii by nptelhrd. Chapter 2 lecture notes the first law of thermodynamics. Third law of thermodynamics entropy at absolute zero. The second law of thermodynamics introduces the notion of entropy s, a measure of system disorder messiness u is the quantity of a systems energy, s is the quality of a systems energy. This has led to much debated issues, such as whether the distinction between past and future can be grounded in the second law, or how to reconcile the second law with an underlying microscopic.
And the second law of thermodynamics, according to rudolf clausius, and im gonna paraphrase this, is that we dont see spontaneous, let me write this down. Clasius, kelvin, and carnot proposed various forms of the second law to describe the particular physics problem that each was studying. Lets start with one of the most common ways to state it, which is, if youve got a cold object and a hot object, heat will never be seen to flow spontaneously from a colder object to a hotter. Introduction to second law of thermodynamics youtube. The second law of thermodynamics explains the phenomenon of irreversibility and the increasing entropic trend of nature. Second law of thermodynamics georgia state university. The first law of thermodynamics university college dublin. In so doing, it goes beyond the limitations imposed by the first law of thermodynamics. This does not conflict with notions that have been observed of the fundamental laws of physics, namely cpt symmetry, since the second law applies statistically, it is hypothesized, on timeasymmetric boundary conditions.
Good afternoon i welcome you all to this lecture section of the course laws of thermodynamics. This course is on basic engineering thermodynamics. However, those contents do not necessarily represent the policy of fipse and the department of education, and. For the reversible isothermal process, for the gas. Lec4 second law of thermodynamics nptel thermodynamics. Lec4 second law of thermodynamics nptel thermodynamics lec4 second law of thermodynamics lecture series on applied thermodynamics for marine systems by prof. This law states consider three bodies namely a, b, c, if a and b are individually in thermal equilibrium with a third body c then, the bodies a and b also will. He said, we dont see a spontaneous transfer of heat from cold areas to hot areas. Apr 03, 2016 the application of first law of thermodynamics process led to the establishment of a new property named internal energy u, the application of the second law to a process leads to the establishment of another new property names as entropy s. Second law of thermodynamics increased entropy the second law of thermodynamics is commonly known as the law of increased entropy. Hindi second law of thermodynamics l heat engine l heat pump l refrigerator l gate 2018 mechanical duration. The first law places no restriction on the direction of a process, and satisfying the first law does not guarantee that the process will occur. Similar to humanmade machines, living structures are subjected to entropy.
The answer to such irreversibility resides the second law of thermodynamics which explained in this and the next lecture. The second law of thermodynamics and carnots engine. Som, department of mechanical engineering, iit kharagpur. Explore the three laws of thermodynamics thoughtco. From a plot of pressure versus piston displacement, a closed figure was produced, whose area represented the power developed by the engine. The nernst statement of the third law of thermodynamics implies that it is not possible for a process to bring the entropy of a given system to zero in a finite number of operations. Second law of thermodynamics, entropy and availbility. Physical processes in nature can proceed toward equilibrium spontaneously. Work and efficiency as motivation for the development of the second law, we examine two types of processes that. The first law says that the energy of the universe is constant. Phys 200 lecture 23 the second law of thermodynamics and. This law was developed by the german chemist walther nernst between the years 1906 and 1912.
The 2nd law of thermodynamics heat can be completely converted into work in a single process but continuous conversion of heat in to work requires a cyclic process a heat engine all attempts to construct a heat engine that is 100% efficient have failed the kelvin planck statement of the. The third law of thermodynamics states that the entropy of a system approaches a constant value as the temperature approaches absolute zero. Its implications may be visualized in terms of the waterfall analogy. Advanced metallurgical thermodynamics nptel online. So, im going to put up a couple of just statements of the second law of thermodynamics. Thus power generation processes and energy sources actually involve conversion of energy from one form to another. The increase of the internal energy of a system is equal to the sum of the heat added to the system plus the work done on the system. This principle explains, for example, why you cant unscramble an egg. The simplest statement of the first law is as follows.
Nptel video lectures, iit video lectures online, nptel youtube lectures, free video lectures, nptel online courses, youtube iit videos nptel courses. Nptel nptel online certification course course on laws. The entropy of a system at absolute zero is typically zero, and in all cases is determined only by the number of different ground states it has. Why does a dropped egg that spatters on the floor not rise back to your hands even though no laws prohibit it. The second law of thermodynamics is concerned with the maximum fraction of a quantity of heat that can be converted into work.
The law of conservation of energy states that the total energy of an isolated system is constant. Aug 19, 2016 this video tell why second law, discuss about engine cycles, kelvin plank and clausius statements, refrigerator and heat pump and their cops for more explanation refer engineering thermodynamics. Alternate statements of the 3 rd law of thermodynamics. According to joules law, under these conditions the temperature of the gas does not change, which implies. Second law of thermodynamics the first law of thermodynamics is a statement of the principle of conservation of energy. Thermodynamics effects of work, heat and energy on systems. The second law of thermodynamics the second law of thermodynamics asserts that processes occur in a certain direction and that the energy has quality as well as quantity. As described in class and as derived in almost every thermodynamics textbook, although the three may not appear to have much connection with each other, they are equivalent.
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