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A very small circular cylinder of radius Rtis rotating angular velocity
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Fluid Mechanics: Fundamentals and Applications
- The belt in the Ögure moves at steady velocity V and skims the top of a tank of oil having viscosity. (a) Develop and expression for the required belt drive power in terms of h, L, b, V , and . Recalthat, for steady motion, power is equal to force velocity.(b) What power is required if the belt moves at 5 m/s over SAE 50W oil ( = 0:86 kg/ms) withh = 2 cm, L = 2 m, and b = 0:5 marrow_forwardA rotating viscometer consists of two concentriccylinders—an inner cylinder of radius Ri rotating at angularvelocity (rotation rate) vi, and a stationary outer cylinder ofinside radius Ro. In the tiny gap between the two cylindersis the fluid of viscosity m. The length of the cylinders is L. L is large such that end effects are negligible (we can treat this as a two-dimensional problem). Torque (T) is required to rotate the inner cylinder at constant speed. (a) Showing all of your work and algebra, generate an approximate expression for T as a function of the other variables. (b) Explain why your solution is only an approximation. In particular, do you expect the velocity profile in the gap to remain linear as the gap becomes larger and larger (i.e., if the outer radius Ro were to increase, all else staying the same)?arrow_forwardpllllzzzz help me right nowww plzzz The belt moves at a steady velocity V and skims the top of oil tank. Assuming a linear velocity profile in the oil, what is the required belt-drive power P (watt) (P= power = force x Velocity) if the belt moves at 3.5 m/s over oil with specific gravity of S=3.6 and oil viscosity of 0.004 m2/s. Belt geometry L= 2 m, b = 60 cm, and oil depth is h = 3 cm?arrow_forward
- A two-dimensional fluid element of dimensions dx and dy translates and distorts as shown, during the infinitesimal time period dt = t2 − t1. The velocity components at point P at the initial time are u and ? in the x- and y-directions, respectively. Show that the magnitude of the rate of rotation (angular velocity) about point P in the xy-plane isarrow_forwardTwo concentric cylinders of radii a and b respectively (a > b) have their common axislying along the z-axis. The space between them b < r < a contains fluid of viscosity µ.A flow is generated by moving the outer cylinder with constant speed U parallel to itsaxis whilst the inner cylinder remains at rest. 1. Use cylindrical polar coordinates (r, θ, z) and consider an elementary fluid elementof lengths dr and dz and angle dθ (measured from the z-axis). Draw a diagramshowing the forces acting on the surfaces of the fluid element. 2. Determine the velocity distribution u in thez-direction, stating any assumptions you make.arrow_forwardThis question is related to fluid mechanicsarrow_forward
- A cylinder with a length of 1.2 m anda diameter of 2 cm rotate insideanother cylinder with same lengthand a diameter of 2.11 cm.Calculate the momentum requiredfor the rotating of the insidecylinder with a velocity of 2000rpm if dynamic viscosity betweenthe to cylinders is 10 poisearrow_forwardPlease solve this question in fluid mechanicsarrow_forwardSAE-10 oil at 20 deg C fills the gap between the moving 6 cm diameter long cylinder which is inside a fixed outer cylinder 6.8 cm diameter. Calculate the pressure gradient per unit length needed so the shear stress on the outer cylinder is exactly equal to zero when the inner cylinder is moving with velocity V=4 m/s in the negative z-direction. Assume laminar flow. The viscosity of the oil is 99.2 cp. Express your result in kPa/m and round your numerical answer to a whole numberarrow_forward
- The torque M required to turn the cone-plate viscometer inFig. depends on the radius R , rotation rate Ω , fl uidviscosity μ , and cone angle θ . Rewrite this relation indimensionless form. How does the relation simplify it if itis known that M is proportional to θ ?arrow_forwardIn the following section, at least 2 to up to 5 answers may be correct. 1) For a fluid, the assumption (simplifying notion) of incompressibility has important consequences: Pascal’s principle: a change of pressure in an enclosed fluid at rest is transmitted undiminished to all points in the fluid. pressure changes are transmitted immediately from one place to another. the speed of sound then is infinite (just within this approximation). pressure becomes unpredictable. none of the above. 2) Archimedes’ principle can be summarized as: an immersed object is buoyed up by a force equal to the weight of the fluid it displaces. a bathtub is fun, and may lead to important physical discoveries regarding the volume of an object and how much water it displaces, and the weight of that amount of water. boats swim because of the work done by sailors. submarines are always doomed. fish swim because they are less heavy than water 3) A…arrow_forwardQ7) A flat plate of area 1.5 x 106 mm2 is pulled with a speed of 0.5 m/s relative to another plate located at a distance of 0.2 mm from it. Find the force and power required to maintain this speed, if the fluid separating them is having viscosity as 1 Poisarrow_forward
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