Question A3a) With the help of sketches briefly describe the main differences between laminar andturbulent boundary layers in relation to friction drag and flow separation.A tug boat is pulling a log raft (Figure QA3) on the surface of a lake at a constant speed of Uboat = 5m/s.The log raft can be modelled as a flat plate (L=20m and W = 5.0m).uugUboat8UTug Boat ropeboatAirWaterL-XLog RaftFigure QA3Assume the boundary layer forming on both sides (air side and water side) of the log raft is two-dimensionaland laminar with a second order velocity distribution:Wb) By using the Momentum Integral Equation find an expression for the wall shear stress in terms ofReynolds number and then estimate the tensile stress acting on the rope assuming the rope has acircular cross section with a diameter of 15 mm) and the power required to pull it.c) What would be the tensile stress on the rope if we assume the boundary layers on the log raft wereturbulent?You may assume: Psea-water = 1000 kg/m³,"sea-water -1.0×10-3kg/m.sec,Pair=1.2kg/m³,Hair = 1.8×10-5 kg/m.sec_andug = Uboat-

Problem become significantly easier to solve when we list all the information provided, here below…

b) By using the Momentum Integral Equation find an expression for the wall shear stress in terms of Reynolds number and then estimate the tensile stress acting on the rope assuming the rope has a circular cross section with a diameter of 15 mm) and the power required to pull it. c) What would be the tensile stress on the rope if we assume the boundary layers on the log raft were turbulent?

b) By using the Momentum Integral Equation find an expression for the wall shear stress in terms of Reynolds number and then estimate the tensile stress acting on the rope assuming the rope has a circular cross section with a diameter of 15 mm) and the power required to pull it. c) What would be the tensile stress on the rope if we assume the boundary layers on the log raft were turbulent?

Elements Of Electromagnetics

7th Edition

ISBN:9780190698614

Author:Sadiku, Matthew N. O.

Publisher:Sadiku, Matthew N. O.

ChapterMA: Math Assessment

Section: Chapter Questions

Problem 1.1MA

See similar textbooks

Similar questions

A student team is to design a human-powered submarine for a design competition. The overall length of the prototype submarine is 95 (m), and its student designers hope that it can travel fully submerged through water at 0.440 m/s. The water is freshwater (a lake) at T = 15°C. The design team builds a one-fifth scale model to test in their university’s wind tunnel. A shield surrounds the drag balance strut so that the aerodynamic drag of the strut itself does not influence the measured drag. The air in the wind tunnel is at 25°C and at one standard atmosphere pressure. At what air speed do they need to run the wind tunnel in order to achievesimilarity?
(COLLAB) Simulate projectile motion with air resistance in PhysLab. A shuttlecock is launched from the ground with an initial speed of 36.9688 m/s at an angle of 6.8583 degrees with respect to the horizontal. The shuttlecock experiences air resistance with a drag coefficient of 0.1931 in an environment where the air density is 0.9453 kg/m3. If the shuttlecock has a radius of 3.4 cm and a mass of 5.2 grams, what is the maximum height reached by the shuttlecock? Assume that the experiment is done near the surface of the earth (initHeight = 0) .
An engineer is to design a human powered submarine for a design competition. The overall length of the prototype submarine is 2.24 m and its engineer designers hope that it can travel fully submerged through water at 0.560 m/s. The water is freshwater (a lake) at 7-15°C (p=999.1 kg/m3 and u= 1.138 ×103 kg/m-st. The design team builds a one-eighth scale model to test in their university's wind tunnel. The air in the wind tunnel is at 25°C (p= 1.180 kg/m3 and u = 1.849 ×10-5 kg/m-s) and at one standard atmosphere pressure. At what air speed do they need to run the wind tunnel in order to achieve similarity?
Consider a boundary layer growing along a thin flat plate. This problem involves the following parameters: boundary layer thickness ? , downstream distance x, free-stream velocity V, fluid density ? , and fluid viscosity ? . The number of primary dimensions represented in this problem is (a) 1 (b) 2 (c) 3 (d ) 4 (e) 5
The drag of a sonar transducer is to be predicted, based on wind (Air) tunnel test data. The prototype is 1.5 m diameter sphere, is to be towed at 4.3 m/s in seawater. The model is 0.2 m diameter. Take: Air density = 1.2 kg/m, Air dynamic viscosity = 1.81 x 10$ Pa. s, seawater density = 1000 kg/m, seawater dynamic viscosity 1.813x 10 Pa s, If the drag of the model at these test conditions is 9.5 N, estimate the drag of the prototype in (N).
Some engineers want a good estimate of drag and boundary-layerthickness at the trailing edge of a miniature wing. The chord and span ofthe wing are 6 mm and 30 mm, respectively and a typical flight speed is5 m/s in air (kinematic viscosity = 15 × 10−6 m2/s; density = 1.2kg/m3). An engineer may decide to make a superseding model withchord and span of 150 mm and 750 mm, respectively. Measurements onthe model in a water channel flowing at 0.5 m/s (kinematic viscosity = 1× 10−6 m2/s, density = 1000 kg/m3) give a drag of 0.19 N and aboundary-layer thickness of 3 mm. Estimate the corresponding values forthe prototype
1. In the figure shown below, choose whether the statement is true or false (Please justify your answer) (a) At a give x-location, if Re were to increase, the boundary layer thickness would decrease. (b) As upstream velocity decreases, so does the boundary layer thickness (c) As the kinematic viscosity increases, so does the boundary layer thickness (d) As the fluid density decreases, so does the boundary layer thickness (e) As the x-location increases, so does the boundary layer thickness
A ship 150 m long, designed to cruise at 18 kn, is to betested in a tow tank with a model 3 m long. If the modelwave drag is 2.2 N, the estimated full-size ship wave drag is( a ) 5500 N, ( b ) 8700 N, ( c ) 38,900 N,( d ) 61,800 N, ( e ) 275,000 N
The so-called Rocket Man, Yves Rossy, fl ew across the Alps in2008, wearing a rocket-propelled wing-suit with the followingdata: thrust = 200 lbf, altitude = 8,200 ft, and wingspan = 8 ft(http://en.wikipedia.org/wiki/Yves_Rossy). Further assume awing area of 12 ft2, total weight of 280 lbf, CDq = 0.08 for thewing, and a drag area of 1.7 ft2 for Rocket Man. Estimate themaximum velocity possible for this condition, in mi/h.
(b) In two dimensional boundary layer, shear stress was changed linearly from the solid surface toward y-axis until it reach the value of zero at y = ở. Based on Table 2 and setting given to you; (i) Derive the equation of displacement thickness and momentum thickness using Von Karman Approximation Method ; and (ii) Determine the accuracy of this method in determining the value of displacement thickness and momentum thickness. C5 Table 2: Equation of Velocity Profile Setting Equation wU = 2y/8 - (y/S² 1
You are designing an airfoil for a new hobby RC plane. Because of your limited knowledge, you have mistakenly approximated your airfoil as an ellipse with a = 75mm and b = 12mm. Here, “a” is the depth of your wing and “b” is the thickness. Your plane travels through the air at approximately 20mph (8.9m/s). As it does so, skin friction produces a drag-induced heat of 800W on your wind, of length 1m. Properties of Air: k = 0.025 W/mK, Pr = 0.72, v = 1.847 x 10−5, u = 16.84 x 10−6, p = 1.2 kg/m3, B = 1/Tf (ideal gas), TInfinity = 25oC a) What is the average temperature of your wing? Assume an ellipse perimeter of approximately 200mm.
You are designing an airfoil for a new hobby RC plane. Because of your limited knowledge, you have mistakenly approximated your airfoil as an ellipse with a = 75mm and b = 12mm. Here, “a” is the depth of your wing and “b” is the thickness. Your plane travels through the air at approximately 20mph (8.9m/s). As it does so, skin friction produces a drag-induced heat of 800W on your wind, of length 1m. Properties of Air: k = 0.025 W/mK, Pr = 0.72, v = 1.847 x 10−5, u = 16.84 x 10−6, p = 1.2 kg/m3, B = 1/Tf (ideal gas), TInfinity = 25oC a) What is the Reynold’s number? Hint: “D” is taken to be the thickness for an elliptical crosssection. b) What is the Nusselt number? c) What is the convection coefficient? d) What is the average temperature of your wing? Assume an ellipse perimeter of approximately 200mm.