When solving the this HW, use the follow relations to determine any necessary drag coefficients for flat plates: Laminar
Posted: Tue Apr 26, 2022 4:58 pm
- When Solving The This Hw Use The Follow Relations To Determine Any Necessary Drag Coefficients For Flat Plates Laminar 1 (54.34 KiB) Viewed 43 times
problem. I want to know how to approach these problems so can you
please show all work and explain how to get there, this is my last
question and I really need this, I will rate though!
When solving the this HW, use the follow relations to determine any necessary drag coefficients for flat plates: Laminar Turbulent Mixed Valid Range Re < 5 · 105 5. 105 < Re < 107 107 < Re < 109 5. 105 < Re < 109 1700 Cof 1.328 (Rel)1/2 0.0740 (Rel)1/5 0.455 (log10 Rel)2.58 0.455 (log10 Rel)2.58 REL
3. You are working as a naval engineer researching different ways to reduce the fuel costs for ships. One company suggests attaching a parachute-like sail near the front of a ship to reduce the required power output from the engine. To analyze the effectiveness of this design, consider a 130-m-long ship. You may treat the hull of the ship under the water line as a flat plate with an effective wetted area of 3000 m². The sail has a drag coefficient Cp = 0.8 and an area of 350 m², and the sail makes an angle of 25° with the horizontal. Take the typical wind speed to be 50 km/h, air to have a typical density of Pa = 1.23 km/m3, and sea water to have density and dynamic viscosity p= 1025 kg/m3 and u = 0.00107 Pa-s, respectively. TIE 111 a) Considering the boat's hull to be rough, the boundary layer physics will be entirely turbulent. Referencing the beginning of this HW, there are two possible ways to calculate the drag coefficient for entirely turbulent boundary layers. Do you need to account for both approaches when analyzing this system? (Hint: for what ship velocity would you have to switch between the two relations? Do you think it is reasonable to consider ship velocities only slower (or faster) than this velocity?) b) Determine the steady-state velocity of the ship when the motor is turned off. Note that the sail sees the relative velocity of the wind. You will have to use some sort of iterative solver to get an answer. c) Determine the velocity of the boat when the propeller provides 2 MW of propulsion power. d) If the propeller power is halved to 1 MW, what is the percent change in the ship velocity? Does it seem like halving the propeller power is a good choice?