Sangoro CBE 240 Final Exam question n answers rated A+

Sangoro CBE 240 Final ExamTwo different Newtonian Fluids (A&B) are placed between identical sets of parallel plates as shown below. Each pair of plates is separated by the same distance. Both bottom plates are pulled to the right at a constant velocity and both top plates are held stationary. The force required to pull the bottom plate in contact with fluid A is twice the force required to pull the bottom plate in contact with fluid B. The only motion occurring in each fluid is caused by the movement of the bottom plate. How are the viscosity of the two fluids related? How are the densities of the plates related? - correct answer The viscosity of A > viscosity of B because the force required to move the plate is directly proportional to viscosity The densities are unrelated because the force required to move the plate is only a function of fluid viscosity Water is placed between two parallel plates. The bottom plate moves to the right at a constant velocity and top plate is stationary. Draw the water velocity profile at steady state? In Which direction is the x-momentum being transferred? - correct answer Pic: triangle point at top Answer: Transfer is in the +y direction because momentum is transported from a region of high momentum to low momentum Draw the shear rate vs. Viscosity graph? With an increase in the shear rate, the apparent viscosity of dilatant fluids acts how? - correct answer increases The viscosity is lowest at which rate of shearing strain? - correct answer See picture on quiz 1 question 4 If mass, length, and time are selected as the three fundamental dimensions, the dimensions of viscosity in the SI unit system could be written as - correct answer M/LT The velocity profile in a 4 cm diameter pipe transporting 20C water is given by v(r)=10(1-2500r^2) m/s. if the viscosity of the water is 1 mPas and the density is 997 kg/m3, the shearing stress at the wall is nearest - correct answer 1Pa A liquid flows through a pipe at a Reynolds number of 2250. What type of flow is it? - correct answer transitory, oscillating between laminar and turbulent View question 3 quiz 2. - correct answer No shear stress where velocity move without problem in velocity profile In the statement of Newtons law of viscosity, the dimension of velocity gradient in the MLT system is - correct answer 1/T View question 5 quiz 2. - correct answer Compare answer to question 4 quiz 1 A cylindrical mixing tank is to be scaled up to a larger size such that the volume of the larger tank is nine times that of the smaller one. The ratios of diameter and heights between the two is? - correct answer 2.08 Liquid flow through a pipe has a Reynolds number of 5250. What is its state? - correct answer turbulent Consider a boundary layer growing along a thin flat plate. This problem involves the following paramenters: thickness, distance, velocity, density, and viscosity. The dependent parameter is thickness. If we choose the three repeating parameters as x, p, v, what is the dependent pi? - correct answer thickness/distance The power input P, to a centrifugal pump is a function of the volumetric flow, Q, the impeller distance, D, the rational rate, ohm, the density, p, and viscosity, mu. such that P=f(the rest). How many dimensionless groups are there? - correct answer 3 A Newtonian fluid flows under steady, laminar conditions, through a circular pipe of diameter .16m at a vol flow rate of .05 m3/s. Under these conditions, the maximum local velocity at a section is? - correct answer 5 The shear stress profile for steady state, fully developed, laminar flow in a tube is linear/quadratic in the radial/axial direction - correct answer linear, radial The velocity profile for a bingham plastic under laminar conditions in a pipe makes what shape? - correct answer Parabolic towards walls flat in center