Physical Mechanics

This title is intended as a textbook for teaching physical mechanical. The course sets out the basic concepts of technical thermodynamics, classical continuum mechanics, mechanics of a deformed solid, fluid dynamics, gas dynamics and stability of the theory and the turbulence necessary to study the fundamentals and the subsequent examination of the physical mechanics.

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Physical mechanics is based on the microstructure of matter, using the achievements of modern physics, physical chemistry, quantum chemistry and other sciences to describe the motion of the real media used in engineering practice. The term “physical mechanics” was introduced by one of the greatest engineers of our time, a PhD student of Prandtl, the father of China's space and nuclear programs, Qian Xue-sen.

Physical mechanics in the modern sense is from one side the part of continuum mechanics, in which the properties of the medium can be changed under the influence of applied forces or energy impacts. On the other hand, the physical mechanics objects are not described by the continuum equations. These include, for example, low-density gas, plasma, rheology media, multi-phase flows consisting of droplets in a gas or bubbles in liquids, and the intermediate states with different gas content, dusty gas and plasma, foams, nano-sized objects. For description of objects in physical mechanics it is not enough equations of continuum mechanics, but kinetic description is necessary, i.e. use of the kinetic Boltzmann equation, or other classical kinetic equations, and in some cases quantum equations. The physical state of matter in physical mechanics can be liquid, gas, plasma, single-and multi-phase, the medium may consist of mixtures of different components, among which chemical reactions occur, it may be under the influence of various bulk and surface forces of the gravitational, electromagnetic and inertial forces nature. As an example, studied the physical mechanics, we consider the motion of the plasma in an electromagnetic field when the external magnetic field acts on the flow and the moving medium generates electric currents that create magnetic fields, resulting in a need of self-consistent solution of problems. Another example of the need of self-consistent solution of nonlinear problems, are the processes of combustion and detonation occurs when the shock wave compression of the gas temperature rises so much that dissociation and ionization of the gas occur, which lead to a change in medium compressibility, i.e. changing the medium reaction to the external influences. Another example of necessity self-consistent solution is the turbulent flow, which are studied in continuum mechanics of classical fluids and gas, and for media with chemical reactions in a conducting medium in electromagnetic fields, in the presence of electromagnetic radiation in nonequilibrium gases and plasma, takes additional methods of solution.

The book is based on a course of lectures delivered at the Moscow Institute of Physics and Technology at the Department of Physical Mechanics, Faculty of Aerophysics and space research and is intended as a textbook for teaching the subject. The author seeks to as concisely as possible articulate key concepts and provisions. The course sets out the basic concepts of technical thermodynamics, classical continuum mechanics, mechanics of a deformed solid, fluid dynamics, gas dynamics and stability of the theory and the turbulence necessary to study the fundamentals and the subsequent examination of the physical mechanics. The proposed course is enough strict, ie does not require other textbooks to get the results cited. The manual is accompanied by qualitative explanations that take into account at the initial level of knowledge in mathematics - differential equations and mathematical physics. The course consists of theoretical lectures and seminars that address practical problems and laboratory training. Laboratory workshop represented a separate publication. Numerical simulation is now of instruments used not only for the construction of settlements, necessary for comparison with experiments, but also an effective method of design new complex technological objects. This course provides examples of numerical solutions of simple problems that are available by using software packages such as MAPLE, MATHCAD, MATHEMATICA, and the numerical simulation of near-real physical mechanics problems are presented by separate edition. In the textbook are used the experimental results and obtained by numerical simulation at the Department of Physical Mechanics, Faculty of Aerophysics and Space Research of the Moscow Institute of Physics and Technology.