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In physics, fluid dynamics is a sub-discipline of fluid mechanics that deals with fluid flow —the natural science of fluids (liquids and gases) in motion.
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In physics, fluid dynamicsis a sub-discipline of fluid mechanics that deals with fluid flow—the natural science of fluids (liquids and gases) in motion It has several sub-disciplines itself, including aerodynamics (the study of air and other gases in motion) and hydrodynamics (the study of liquids in motion). In physics, a fluid is a substance that continually deforms (flows) under an applied shear stress. Fluids are a subset of the phases of matter and include liquids, gases, plasmas
Equation 14-7 also holds above the liquid surface: In general, the difference between an absolute pressure and an atmospheric pressure is called the gauge pressure (because we use a gauge to measure this pressure difference). For Fig. 14-3, the gauge pressure is . all tie ρgh
Substitute into Eq. 14-7, finding that For a given pressure, the height h of the mercury column does not depend on the cross-sectional area of the vertical tube. An open-tube manometer (Fig. 14-6) measures the gauge pressure pgof a gas. Substitute into Eq. 14-7, finding that
Pascal's principle states that when there is an increase in pressure at any point in a confined fluid, there is an equal increase at every other point in the container. Let us add a little more lead shot to the container to increase pext by an amount ∆pext.
Equation 14-13 shows that the output force Foon the load must be greater than the input force Fiif Ao >Ai, as is the case in Fig. 14-8. This shows that, if Ao>Ai(as in Fig. 14-8), the output piston moves a smaller distance than the input piston moves.
Summery P1 = P2 Winput = Woutput
Buoyant force Buoyant forceis an upward force exerted by a fluid that opposes the weight of an immersed object.
(a) all tie (the gravitational force on the penguin is the same); (b) 0.95ρ0, ρ0, 1.1ρ0
1. Steady flow In steady (or laminar) flow, the velocity of the moving fluid at any fixed point does not change with time. 2. Incompressible flow We assume, as for fluids at rest, that our ideal fluid is incompressible; that is, its density has a constant, uniform value. 3. Nonviscous flow the viscosity of a fluid is a measure of how resistive the fluid is to flow. Thus an object moving through a nonviscous fluid would experience no viscous drag force—that is, no resistive force due to viscosity; it could move at constant speed through the fluid Figure 14-12 4. Irrotational flow It is also assumed that the flow is irrotational. For example in irrotational flow the test body (particle) will not rotate about an axis through its own center of mass.
Lets derive an expression that relates v and A for the steady flow of an ideal fluid through a tube with varying cross section, like that in Fig. 14-15. Applying Eq. 14-22 to both the left and right ends of the tube segment in Fig. 14-15 Eq: 14-23 tells that when area through which fluid flows increases, the fluid speed decreases.
Where RVis the volume flow rate of the fluid (volume past a given point per unit time). Its SI unit is the cubic meter per second (m3/s). If the density ρ of the fluid is uniform, we can multiply Eq. 14-24 by that density to get the mass flow rate Rm(mass per unit time): The SI unit of mass flow rate is the kilogram per second (kg/s). 13 cm3/s, outward
In fluid dynamics, Bernoulli's principle states that for a nonconducting ideal fluid (non- viscous fluid) an increase in the speed of the fluid occurs simultaneously with a decrease in pressure or a decrease in the fluid's potential energy. principle of conservation of energy to the fluid (kinetic energy per unit volume) Bernoulli’s equation to fluids at rest
Lets take y to be a constant (y = 0, say) so that the fluid does not change elevation This means where the streamlines are relatively close together (where the velocity is relatively great), the pressure is relatively low, and conversely. (a) all tie; (b) 1, then 2 and 3 tie, 4 (wider means slower) (c) 4, 3, 2, 1 (wider and lower mean more pressure) https://www.youtube.com/watch?v=LMDxv96XluY
