A wind turbine with a 30-m rotor diameter is mounted with its hub at 50 m above a ground surface that is characterized by shrubs and hedges illustrated in Figure 2. Estimate the ratio of specific power in the wind at the lowest point that a rotor blade tip reaches to the highest point it rises to. Pes 65 m 50 m P35 35 m Crops, hedges, shrubs Figure 2 Wind turbine Table 2 Friction coefficient for various terrain characteristics Friction Coefficient Terrain Characteristics Smooth hard ground, calm water Tall grass on level ground High crops, hedges and shrubs Wooded countryside, many trees Small town with trees and shrubs 0.10 0.15 0.20 0.25 0.30 0.40 Large city with tall buildings

A wind turbine with a 30-m rotor diameter is mounted with its hub at 50 m above a ground surface that is characterized by shrubs and hedges illustrated in Figure 2. Estimate the ratio of specific power in the wind at the lowest point that a rotor blade tip reaches to the highest point it rises to. Pes 65 m 50 m P35 35 m Crops, hedges, shrubs Figure 2 Wind turbine Table 2 Friction coefficient for various terrain characteristics Friction Coefficient Terrain Characteristics Smooth hard ground, calm water Tall grass on level ground High crops, hedges and shrubs Wooded countryside, many trees Small town with trees and shrubs 0.10 0.15 0.20 0.25 0.30 0.40 Large city with tall buildings

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 5.32P

See similar textbooks

Similar questions

Consider two identical wind turbines with a hub height of 40 m, one located in flat agricultural land and one located above a forest. What is the relative output power for the two turbines if the wind velocity is 10 m/s at a height of 100 m in both cases? Pagricultural/Pforest = ?
Estimate the amount of power generated by a wind turbine having a powercoefficient of 0.37 given the annual average wind speed:Rotor diameter = 125 mCenter of rotor at an elevation 160 m above the surface level.Location: Oklahoma City, OK
Estimate the annual production of a 12 m diameter horizontal axis wind turbine operating atstandard atmospheric conditions (r = 1.225 kg/m3 ) in an 8 m/s average wind speed regime.
A boat of mass 2500 kg has two hydrofoils, each of chord30 cm and span 1.5 m, with CL,max = 1.2 and CD∞ = 0.08.Its engine can deliver 130 kW to the water. For seawater at20°C, estimate (a) the minimum speed for which the foilssupport the boat and (b) the maximum speed attainable.
A wind turbine with two or four hollow hemispherical cups connected to a pivot is commonly used to measure wind speed. Consider a wind turbine with four 8-cm-diameter cups with a center-to-center distance of 40 cm, as shown. The pivot is stuck as a result of some malfunction, and the cups stop rotating. For a wind speed of 15 m/s and air density of 1.25 kg/m3, determine the maximum torque this turbine applies on the pivot.
What is the maximum power generated by the wind farm with wind speed of 4 m/s? Typical wind turbines have rotor diameters from 40 m to 90 m (Assume increment of 5 m for this problem)-40 m is 80% efficient and efficiency decreases by 5% for every 5 m increase in diameter (i.e. 45 m=75%, 50=70...)-The ridge is 10 km long and wind turbines will be spaced in a single row. •Power in the wind per unit area of circular area is 1/2ρv3W/m2 (v is the wind speed, ρ is 1.3 kg/m3 for air) •Wind turbines cannot be spaced closer than 5 times its diameter without loosing power also there are no partial turbines.
A proposed wind power plant in Batangas is designed to have a power generated output of 30MW. A propeller turbine is to be used. Survey showed that Batangas City has an average airvelocity of 10km/hr. A power coefficient of 0.4 is used and an impeller diameter is assumed notmore than 10 m. Determine the theoretical wind power output.
Consider a steel sphere (SG = 7.85) of diameter 2 cm,dropped from rest in the water at 208C. Assume a constant dragcoefficient CD = 0.47. Accounting for the sphere’s hydrodynamicmass, estimate (a) its terminal velocity and (b) thetime to reach 99 percent of terminal velocity. Comparethese to the results when hydrodynamic mass is neglected,Vterminal ≈ 1.95 m/s and t99% ≈ 0.605 s, and discuss.
Find the draft loss in rectangular breeching 2.59m x 3.67m x 30.48m long when 196 m3/sec flue gas of 0.769 kg/m3 density are flowing.
In this era of expensive fossil fuels, many alternativeshave been pursued. One idea from SkySails, Inc., shownin Fig. is the assisted propulsion of a ship by a largetethered kite. The tow force of the kite assists the ship’spropeller and is said to reduce annual fuel consumptionby 10–35 percent. For a typical example, let the ship be120 m long, with a wetted area of 2800 m2. The kite areais 330 m2 and has a force coefficient of 0.8. The kite cablemakes an angle of 258 with the horizontal. Let Vwind =30 mi/h. Neglect ship wave drag. Estimate the ship speed(a) due to the kite only and (b) if the propeller delivers1250 hp to the water. [Hint: The kite sees the relativevelocity of the wind.]
Estimate the annual production of a 12 m diameter horizontal axis wind turbine operating atstandard atmospheric conditions (r = 1.225 kg/m3 ) in an 8 m/s average wind speed regime. speed probality density is given by the Rayleigh density distribution.
A wind turbine located at a height of 25m from ground, produces 950 kW. Its hub diameter negligible in comparison with length of the blade. Calculate the length of the blade. The average wind velocity is 15 m/s and wind density is 1.25 kg/m3.Gear box efficiency as 85%, Generator efficiency as 75% and Transmission efficiency as 80%. The value of Cp=0.29 and it is a horizontal type of wind turbine.