Newton’s law of internal friction is only applicable to the general fluid and notapplicable to some special fluids. Generally,the fluids in accordance with the law ofNewton internal friction are called “Newtonian fluid”,otherwise the fluids are called“non...[继续阅读]

    Viscosity,i. e. resistance to gradual deformation by shear stress,is a property ofall real fluids. Taking into account the viscosity of fluid complicates the fluid problems.In order to simply the fluid problems,the concept “ideal fluid” was introduced. Id...[继续阅读]

    Fluids can be categorized into compressible and incompressible fluids according tothe difference in the volume reduction of liquid under pressure. The variation of fluiddensity with pressure is very small. The fluid with a constant density can be consider...[继续阅读]

    Surface force is contact force which adjacent fluid or other objects directly exert onthe surface of isolated body of fluid. In other words,Surface force denoted Fs is theforce that acts across an internal or external surface element in a material body. T...[继续阅读]

    Mass force is a force which acts on each fluid particle in the isolated body. Massforce is proportional to mass.Unit mass force is the mass force acting on unit mass fluid:where fx,fy and fz are mass forces which act on unit mass fluid in the direction of...[继续阅读]

    1.1 What’s continuum model of fluid? Continuum model is suitable for the liquidwith bubbles?1.2 Why is water regarded as incompressible fluid?1.3 What’s the most important characteristic of fluids different from solids?1.4 What factors are related to flui...[继续阅读]

    1. If the density of kerosene is 808 kg/m3,how much is the mass and weight of thekerosene with the volume of 2×10-3m3?2.If pistol was pressurized,the volume of the liquid in the cylinder block is 10-3m3when the pressure is 0.1 MPa and the volume is 9.94×1...[继续阅读]

    Compared with solids and flowing fluid,stress force at arbitrary point of astationary fluid has two important characteristics:(1)Surface stress in a stationary fluid is compression stress,i. e. pressure,and thedirection of hydrostatic pressure is the same...[继续阅读]

    For real fluid in motion,viscosity results in the generation of shearing forces due tothe relative movement between fluid layers. The normal stress is not equal in differentdirection at the same point. The dynamic pressure of fluid can be determined byave...[继续阅读]

    In order to analyze the law of fluid balance,an infinitesimally small cube wasconsidered in a fluid at equilibrium as an object of study,and each side of the cube isparallel to the corresponding Cartesian coordinate axis,respectively (see Fig. 2-3). Thepr...[继续阅读]