1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Eduardwww [97]
3 years ago
10

Windmills slow the air and cause it to fill a larger channel as it passes through the blades. Consider a circular windmill with

a D1 = 8m diameter rotor in a V1 = 12m/s wind. The wind speed after the windmill is measured at 8 m/s. (a) (7 pt) Determine the diameter of the wind channel downstream from the rotor (D2). (b) (8 pt) Calculate the power produced by this windmill in kW. Assume air is incompressible and use air density of 1.2kg/m3 .
Engineering
1 answer:
Scilla [17]3 years ago
8 0

Answer:

DIAMETER  = 9.797 m

POWER = \dot W = 28.6 kW

Explanation:

Given data:

circular windmill diamter D1 = 8m

v1 = 12 m/s

wind speed = 8 m/s

we know that specific volume is given as

v =\frac{RT}{P}

  where v is specific volume of air

considering air pressure is 100 kPa and temperature 20 degree celcius

v =  \frac{0.287\times 293}{100}

v = 0.8409 m^3/ kg

from continuity equation

A_1 V_1 = A_2 V_2

\frac{\pi}{4}D_1^2 V_1 = \frac{\pi}{4}D_1^2 V_2

D_2 = D_1 \sqrt{\frac{V_1}{V_2}}

D_2 = 8 \times \sqrt{\frac{12}{8}}

D_2 = 9.797 m

mass flow rate is given as

\dot m = \frac{A_1 V_1}{v} = \frac{\pi 8^2\times 12}{4\times 0.8049}

\dot m = 717.309 kg/s

the power produced \dot W = \dot m \frac{ V_1^2 - V_2^2}{2} = 717.3009 [\frac{12^2 - 8^2}{2} \times \frac{1 kJ/kg}{1000 m^2/s^2}]

\dot W = 28.6 kW

You might be interested in
Define and discuss the difference between micronutrients and macronutrients. Also, discuss their importance in the body at rest
almond37 [142]

Answer:

Macronutrients are simply nutrients the body needs in a very high amount e.g Carbohydrate.

MicroNutrients are simply nutrients the body needs but in little amount e.g  Minerals.

Explanation:

So for further breakdown:

What are nutrients? Nutrients are essential elements that nourish the body in different capacities. We as humans get most of out nutrients from the food and water we ingest.

Now about Macro Nutrients: From the prefix "Macro" which means large, we can infer that macro nutrients are elements need by the body for the fundamental processes of the body, deficiency in this nutrients are very easy to spot. Examples are: Carbohydrates, Protein, Fats amd Water.

Micro Nutrients: In relation to macro nutrients this are elements that the body needs but are not needed in Large quantities. They mostly work like supporting nutrients. Most chemical activities like reaction that occur in the body are a function of micro nutrients. Defiencies in micrp nutrients may take some time to spot e.g Minerals and Vitamins

In regards to exercise: Macro nutrients are the essential ones here since they are the ones that generate energy. PS: micro nutrients dont generate energy.

In regards to rest: Both the Macro and Micro Nutrients are essentail for the overall well being of the body.

5 0
3 years ago
Sharon is designing a house in an area that receives a lot of rainfall all year. Which material should she use to stick the wood
kakasveta [241]

Explanation:

She is passionate about architecture, typography, and black & white film ... Since moving to Texas, I've heard a lot of people say, "If you don't like ... Oc, 3.74, 56, 80 ... Not only does the weather have to be clear to pour the concrete, but it ... system that goes within the slab) is complete, any additional rain will

4 0
3 years ago
A 800-MW steam power plant, which is cooled by a nearby river, has a thermal efficiency of 40 percent. Determine the rate of hea
Arturiano [62]

Answer:

Rate of heat transfer to river=1200MW

So the actual amount of heat rejected ti the river will be less as there will some heat loss to surrounding and in pipes

Explanation:

In order to find the actual heat transfer rate is lower or higher than its value we will first find the rate of heat transfer to power plant:

Efficiency=\frac{work}{heat transfer to power plant}

Heat transfer=\frac{work}{Efficiency\\} \\\\Heat transfer=\frac{800}{0.40}\\\\Heat transfer=2000MW

From First law of thermodynamics:

Rate of heat transfer to river=heat transfer to power plant-work done

Rate of heat transfer to river=2000-800

Rate of heat transfer to river=1200MW

So the actual amount of heat rejected ti the river will be less as there will some heat loss to surrounding and in pipes.

4 0
3 years ago
Pie charts should have no more than eight segments. True or False?
Pepsi [2]

Answer:

Explanation:

Pie charts generally should have no more than eight segments.

6 0
2 years ago
Read 2 more answers
An engineer is going to redesign an ejection seat for an airplane. The seat was designed for pilots weighing between 130 lb and
k0ka [10]

Answer:

A.) 0.3088

B.) 0.0017

C.) part A

Explanation:

A.)

z1= \frac{\left(150-137\right)}{27.7}=0.4693

z2=\frac{\left(201-137\right)}{27.7}=2.3105

P(0.4693

B.)

z1=\frac{150-137}{27.7/ \sqrt{39}} =2.9309\\z2=\frac{201-137}{27.7/ \sqrt{39}}=14.4289

\\P(2.9309

C.) Since the seat performance for an individual pilot is more important than 39 different pilots.

3 0
3 years ago
Read 2 more answers
Other questions:
  • Estudio de caso Teorema de Bayes. Las historias de casos clínicos indican que diversas enfermedades producen sistemas similares.
    14·1 answer
  • OSHA does not approve individual states to have their own safety and health program.
    15·2 answers
  • A civil engineer is asked to design a curved section of roadway that meets the following conditions: With ice on the road, when
    13·1 answer
  • Air is cooled and dehumidified as it flows over the coils of refrigeration system at 100 kPa from 30 ºC and relative humidityof
    14·1 answer
  • A motor driven water pump operates with an inlet pressure of 96 kPa (absolute) and mass flow rate of 120 kg/min. The motor consu
    7·1 answer
  • What forced induction device is more efficient?
    8·2 answers
  • An isothermal CSTR with a first order irreversible reaction A â> B (and rA[mol/(ft3*min)] = - 0.5 CA) has a constant flow rat
    13·1 answer
  • Difference between theory and practice?​
    10·1 answer
  • A new approval process is being adapted by Ursa Major Solar. After an opportunity has been approved, the contract is sent to the
    9·1 answer
  • The controller determines if a(n) _________ exists by calculating the difference between the SP and the PV.
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!