The original Flettner rotor ship was approximately 100 ftlong, displaced 800 tons, and had a wetted area of 3500 ft2. Assketched in Fig. , it had two rotors 50 ft high and 9 ft indiameter rotating at 750 r/min, which is far outside the range. The measured lift and drag coefficients for eachrotor were about 10 and 4, respectively. If the ship is mooredand subjected to a crosswind of 25 ft/s, as in Fig. whatwill the wind force parallel and normal to the ship centerlinebe? Estimate the power required to drive the rotors.

The original Flettner rotor ship was approximately 100 ftlong, displaced 800 tons, and had a wetted area of 3500 ft2. Assketched in Fig. , it had two rotors 50 ft high and 9 ft indiameter rotating at 750 r/min, which is far outside the range. The measured lift and drag coefficients for eachrotor were about 10 and 4, respectively. If the ship is mooredand subjected to a crosswind of 25 ft/s, as in Fig. whatwill the wind force parallel and normal to the ship centerlinebe? Estimate the power required to drive the rotors.

Principles of Heat Transfer (Activate Learning with these NEW titles from Engineering!)

8th Edition

ISBN:9781305387102

Author:Kreith, Frank; Manglik, Raj M.

Publisher:Kreith, Frank; Manglik, Raj M.

Chapter5: Analysis Of Convection Heat Transfer

Section: Chapter Questions

Problem 5.29P: Air at 20C flows at 1 m/s between two parallel flat plates spaced 5 cm apart. Estimate the distance...

See similar textbooks

Similar questions

The 2013 Toyota Camry has an empty weight of 3190 lbf,a frontal area of 22.06 ft2, and a drag coefficient of 0.28. Itsrolling resistance is Crr ≈ 0.035. Estimate the maximumvelocity, in mi/h, this car can attain when rolling freely atsea level down a 4° slope.
A Savonius rotor can be approximatedby the two open half-tubes in Fig mounted ona central axis. If the drag of each tube is similar to thatin Table 7.2, derive an approximate formula for therotation rate Ω, as a function of U, D, L, and the fluidproperties (ρ, μ).
Air flows at Ma = 2.5 past a half-wedge airfoil whoseangles are 4°, as in Fig. Compute the lift and dragcoefficient at α equal to (a) 0° and (b) 6°.
A flying wing weighing 20,000 N has a NACA 65‐418 airfoil section, an area of 30 m2, and an aspect ratio of 5.0. Determine the angle of attack for a sea‐level flight at 60 m/s. What is the lift‐to drag ratio? Assume that the nominal airfoil lift curve slope a0 = 0.106/deg̊, the profile drag CD0 = 0.0043 and e = 0.92.
a)What is the impact of increasing Reynolds number on skin friction and pressure drags over an airfoil? What can be happened for separation in this case? b) What is an adverse pressure gradient and where does it occur on an airfoil (show that on a sketch)? c) Why lift-to-drag ratio is an important parameter for an aircraft? d)How can changing in altitude affect the aircraft power required, PR? Show thatmathematically and graphically?
The airfoil section of the wing of the British Spitfire of World War II fame is an NACA 2213 at the wing root, tapering to an NACA 2205 at the wing tip. The root chord is 8.33 ft. The measured profile drag coefficient of the NACA 2213 airfoil is 0.006 at a Reynolds number of 9 × 106. Consider the Spitfire cruising at an altitude of 19000 ft. Assume that μ varies as the square root of temperature. At this velocity and altitude, assuming completely turbulent flow, estimate the skin-friction drag coefficient for the NACA 2213 airfoil, and compare this with the total profile drag coefficient. Calculate the percentage of the profile drag coefficient that is due to pressure drag. (Round the final answer to three decimal places.) The skin-friction drag coefficient for the NACA 2213 airfoil is .
Air at 20°C and 1 atm flows at 3 m/s past a sharp flat plate2 m wide and 1 m long. (a) What is the wall shear stress atthe end of the plate? (b) What is the air velocity at a point4.5 mm normal to the end of the plate? (c) What is the totalfriction drag on the plate?
A pickup truck has a clean drag area CD A of 35 ft2.Estimate the horsepower required to drive the truck at55 mi/h (a) clean and (b) with the 3- by 6-ft sign inFig. P7.88 installed if the rolling resistance is 150 lbfat sea level.
Q1/ Boeing 737 - 60 flies at altitude 15000m above sea level with speed 85 m/s and total drag coefficient equal to ( 5) . Find the drag force at this fly condition. Given data IR=287,g=9.81 m/s2 , rho O=0.3648 kg/m2 and wing area = 120m^ ^ 2^ *
Icebergs can be driven at substantial speeds by the wind.Let the iceberg be idealized as a large, flat cylinder, D >> L,with one-eighth of its bulk exposed, as in Fig.. Letthe seawater be at rest. If the upper and lower drag forcesdepend on relative velocities between the iceberg and thefluid, derive an approximate expression for the steady icebergspeed V when driven by wind velocity U.
Read the question carefully and give me right solutions with clear calculations. The air flows past a 1m diameter disk oriented normal to upstream flow at 6.8m/s. The pressure distribution on front of the disk is function of the radius, where p(r) = (25 − 100 r2 ) N/m2 , and the pressure acts uniformly on back side with suction pressure of pback = −22 P a. a. Determine the total drag force on the disk. b. Calculate the drag coefficient for the disk . (Density = 1.25 kg/m3 ).
Assume the stabilizer of an airplane is a flat plate. If the transition /critical RN 750,000, what is the skin-friction drag of a rectangular stabilizer having a span of 1.73 m and a chord of 0.81 m at a speed of 44.7 meters per second? Assume standard sea level conditions.