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Doc Hello continuous medium hypothesisContinuous medium hypothesis of fluid mechanics and solid mechanics as one of basic hypothesis.It thinks that the actual fluid or solid occupied space can be considered as continuous void-free full of "particle".Particle with the macroscopic physical quantities (such as mass, velocity, pressure, temperature etc.) meet all should follow the laws of physics, for example the law of conservation of mass, Newton's laws of motion, the law of conservation of energy, the laws of thermodynamics and diffusion, viscosity and thermal conductivity and other transport properties of fluids and solids, but also some physical constants by the experiment to determine.The processing fluid and solid macroscopic motion method, has been widely used in fluid mechanics and solid mechanics, and obtained great success.The so-called particle refers to the microcosmic, macroscopical on sufficiently large and small molecules (also called micro regiment).On one hand, molecules of the scales and molecular motion compared must be large enough, the molecules contain a large number of molecules, the molecule group statistical averaging can be determined value.On the other hand, requires molecules of the scales and the study characteristic scale compared to http://www.adidasjeremyscottc.com/ make small, makes a molecule of average physical quantity can be regarded as uniform invariant, and thus can be considered as a geometry of molecules on a point.For the statistical average of the time, ask for it is microcosmic, macroscopical sufficiently short full length.The statistical average of the time should be long enough, so during this time, microscopic properties, such as molecular collisions Adidas Porsche Design Bounce S2 have been carried out many times, during this time were statistically average can be determined by numerical.On the other hand, statistical average macroscopic time also should be better than the study characteristic time much smaller, so that we can make the average time as a moment.Continuous medium hypothesis in the general case is established.For example in the freezing temperatures and an atmospheric pressure (1 atm = 101325 kPa), a cubic centimeter volume contained gas molecule number is about 2.7 1019 10-9 cubic centimeter, even in such a macro to say very small volume is 2.7 x 1010 molecules, this volume from the microscopic aspect seems to be very big.On the other hand, in the freezing temperatures and a big pressure, per cubic centimeter of gas molecules in seconds to impact 1029 times, so in 10-6 seconds such macroscopical view within a short time, even in very small volume (such as 10-9 cubic centimeter) within the molecule remains to collide with 1014 this time, from microcosmic also seems to be long enough.But in some special problems, continuous medium hypothesis may also not established.For example in a rarefied gas, the distance between molecules, and object characteristic scale compared; although access to determine the average values of the molecular groups also exist, but it can not be regarded as a particle.Also consider shock gas within the movement, shock thickness and the mean free path of the same order of magnitude, shock wave within the fluid can Adidas Porsche Design Bounce S look into molecules and can not be regarded as a continuous medium to handle.The continuum hypothesis, the spatial point in each and every moment has a definite physical quantity.The physical quantity is generally said to be Adidas Porsche Design the space coordinates and the continuous function of time, which can use the powerful tools of mathematical analysis.