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Consider the general form of the Reynolds transport theorem (RTT) given by
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FLUID MECHANICS FUNDAMENTALS+APPS
- Consider the general form of the Reynolds transport theorem (RTT) given by dBsys / dt = d/dt ∫CV ρb dV +∫CS ρbV-› r·n-› dAwhere V-›r is the velocity of the fluid relative to the control surface. Let Bsys be the mass m of a closed system of fluid particles. We know that for a system, dm/dt = 0 since no mass can enter or leave the system by definition. Use the given equation to derive the equation of conservation of mass for a control volume.arrow_forwardA stream function is given by = 4x – 3y. The resultant velocity at any point isarrow_forwardYou are given the velocity profile within a thin layer of liquid, draining from an inclined plane as vx = v0 (ay/h − y2/h2), where v0 is the surface velocity and a is a constant that needs to be determined. The height of the liquid film h = 2 cm and the flow rate is 1.8liters/minute. The plane has width 10 cm into the paper.(i). Determine the constant a by applying a suitable boundary condition at y = h.arrow_forward
- b) A Newtonian fluid flows in an annular space created by a concentric pipe of radius R, and a rod of radius R;, as shown in Figure Q1(b). The rod is moving at a constant velocity V, while the pipe is stationary. The flow is steady, laminar and incompressible and there is no forced pressure gradient driving the flow. Assuming the velocity components in the radial and tangential directions are zero and ignoring the effects of gravity, derive an expression for the velocity field in the annular space. R. R: Figure Q1(b)arrow_forwardA fixed control volume has three one-dimensional boundary sections, as shown. The flow within the control volume is steady. The flow properties at each section are tabulated below. Find the rate of change of energy of the system which occupies the control volume at this instant. Section Туре P. kg/m V, m/s A, m? e, J/kg 1 Inlet 800 5.0 2.0 300 Inlet 800 8.0 3.0 100 3 Outlet 800 17.0 2.0 150 CVarrow_forwardThe flow between two horizontal infinite parallel plates is a two-dimension, steady-state, incompressible and fully- developed flow. The distance between the plates is h m. The bottom plate is stationary and the top plate velocity is U. m/s in the x-direction. The flow is driven by the top moving plate and there is, therefore, no pressure gradient in the direction of the flow. Velocity in the y-direction, v = 0. Note: Align the x-axis to the bottom wall. Use the x-momentum equation to show that the velocity profile equation is (a) u(y) = ay + b and find the values of a and b. Use the energy equation to derive the temperature distribution T(y) for the flow if the surface temperature and temperature gradient on the bottom plate are both zero. (b)arrow_forward
- Fluid Dynamics questionarrow_forward3. A circular cylinder of radius a is fitted with two pressure sensors to measure pressure at 0 = 180° and at 150°. The intent is to use this cylinder as a stream velocimeter, i.e. a device to determine the velocity of a stream by measuring the pressures at the two taps. The fluid is incompressible with a density of p. Figure for Part (a) U Figure for Part (b) 30 a) Using potential flow approximation, derive a formula for calculating U from the measured pressure difference at the two pressure taps. Note that for accurate measurement, the velocimeter must be aligned to have one of the taps exactly facing the stream as shown in the figure. (Ans: 2|Aptaps|/p ) b) Suppose the velocimeter has been misaligned by ổ degrees so that the two pressure taps are now at 180° + 8 and 150° + 8. Derive an expression for the percent error in stream velocity measurement. Then, calculate the error for 8 = 5°,10° and –10°. (Ans: [2/(sin2(150 + 8) – sin²(180 + 8) )– 1] × 100 )arrow_forwardnavier stokesarrow_forward
- An incompressible Newtonian fluid having a thickness of h, flows steadily in the x- direction along a fixed wall of infinite extent by the influence of the gravitational force (g=9.81 m/s²). There is no pressure change in the flow direction and air friction is negligible. Using the given parameter values; a determine the velocity function, b. calculate the shear stress that will occur along the wall. Z fixed wall air h 0 16.0 ↓arrow_forwardOne of the oldest equations in fluid mechanics deals with the flow of a liquid from a large reservoir. Using the Bernoulli equation along the streamline, (a) find out the velocity in m/s at the exit (location (2)) when h = 20 m and (b) find out the velocity in m/s at the location (5) for H = 4 m. Here the gravitational acceleration (g) can be approximated to be 10 m/s². h 147 H d (5) • (1) (3) (2) (4)arrow_forwardQ2/ Suppose you have crude oil flows through an annulus between two horizontal pipes with the same center, if the velocity distribution v, and the average velocity Vavg are expressed by: ΔΡ Rr²+ R² In (R₂/R₁) (¹) In 4μL ΔΡ Vavg = R₁ + R₂ R - R In (R₂/R₁ 8µL Where AP: is the pressure drop through the annulus, μ: is the fluid viscosity, L: is the pipe length, R₁ and R₂: are the inside radius of inner and outer pipes, respectively. Write a program in a script file that calculates the velocity distribution and the average velocity. When the script file is executed, it requests the user to input AP, μ, L, R₁ and R₂ where r has many values between R₁ and R₂. The program displays the inputted values and the calculated average velocity (using fprintf) followed by a table with the values r in the first column and the corresponding values of the velocity distribution in the second column.arrow_forward
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