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
Sauron [17]
3 years ago
13

An air-standard Diesel cycle has a compression ratio of 16 and a cutoff ratio of 2. At the beginning of the compression process,

air is at 95 kPa and 278C. Accounting for the variation of specific heats with temperature, determine (a) the temperature after the heat-addition process, (b) the thermal efficiency, and (c) the mean effective pressure
Physics
1 answer:
Sedbober [7]3 years ago
3 0

Answer:

a.T_3=1723.8kPa\\b.n=0.563\\c.MEP=674.95kPa

Explanation:

a. Internal energy and the relative specific volume at s_1 are determined  from A-17:u_1=214.07kJ/kg, \ \alpha_r_1=621.2.

The relative specific volume at s_2 is calculated from the compression ratio:

\alpha_r_2=\frac{\alpha_r_1}{r}\\=\frac{621.2}{16}\\=38.825

#from this, the temperature and enthalpy at state 2,s_2 can be determined using interpolations T_2=862K and h_2=890.9kJ/kg. The specific volume at s_1 can then be determined as:

\alpha_1=\frac{RT_1}{P_1}\\\\=\frac{0.287\times 300}{95} m^3/kg\\0.906316m^3/kg

Specific volume,s_2:

\alpha_2=\frac{\alpha_1}{r}\\=\frac{0.906316}{16}m^3/kg\\=0.05664m^3/kg

The pressures at s_2 \ and\  s_3 is:

P_2=P_3=\frac{RT_2}{\alpha_2}\\\\=\frac{0.287\times862}{0.05664}\\=4367.06kPa

.The thermal efficiency=> maximum temperature at s_3 can be obtained from the expansion work at constant pressure during s_2-s_3

\bigtriangleup \omega_2_-_3=P(\alpha_3-\alpha_2)\\R(T_3-T_2)=P\alpha(r_c-1)\\T_3=T_2+\frac{P\alpha_2}{R}(r_c-1)\\\\=(862+\frac{4367\times 0.05664}{0.287}(2-1))K\\=1723.84K

b.Relative SV and enthalpy  at s_3 are obtained for the given temperature with interpolation with data from A-17 :a_r_3=4.553 \ and\  h_3=1909.62kJ/kg

Relative SV at s_4 is

a_r_4=\frac{r}{r_c}\alpha _r_3

==\frac{16}{2}\times4.533\\=36.424

Thermal efficiency occurs when the heat loss is equal to the internal energy decrease and heat gain equal to enthalpy increase;

n=1-\frac{q_o}{q_i}\\=1-\frac{u_4-u_1}{h_3-h_2}\\=1-\frac{65903-214.07}{1909.62-890.9}\\=0.563

Hence, the thermal efficiency is 0.563

c. The mean relative pressure is calculated from its standard definition:

MEP=\frac{\omega}{\alpa_1-\alpa_2}\\=\frac{q_i-q_o}{\alpha_1(1-1/r)}\\=\frac{1909.62-890.9-(65903-214.7)}{0.90632(1-1/16)}\\=674.95kPa

Hence, the mean effective relative pressure is 674.95kPa

You might be interested in
Select the option that best summarizes the reason for the use of position-time graphs when studying physical science. (1 point)
Sedaia [141]

The position-time graphs show the relationship between the position of an object (shown on the y-axis) and the time (shown on the x-axis) to show velocity.

<h3>What is velocity?</h3>

Velocity is a vector quantity that tells the distance an object has traveled over a period of time.

Displacement is a vector quality showing total length of an area traveled by a particular object.

Imagine a time-position graph where the velocity of an object is constant. What will be observed on the graph concerning the slope of the line segment as well as the velocity of the object?

The slope of the line is equal to zero and the object will be stationary.

The position-time graphs show the relationship between the position of an object (shown on the y-axis) and the time (shown on the x-axis) to show velocity.

To learn more about velocity refer to the link

brainly.com/question/18084516  

#SPJ2

4 0
1 year ago
Read 2 more answers
3. Convert 588 km/hr to m/s.​
Luden [163]

Answer:

= 163.3 m/sec

hope it helps

7 0
3 years ago
A body is travelling with a velocity 30 m/s².what will be its velocity after 4s?​
Ipatiy [6.2K]

Answer:

70m/s²

Explanation:

we will use the first equation of Dalton to find it

3 0
3 years ago
Which of the following is not true about the Law of Conservation of Energy?
SVEN [57.7K]

By definition, the law of conservation of energy states that:

Ei = Ef

Where,

Ei: initial energy

Ef: final energy

Therefore, no matter the type of energy, always the final energy is equal to the final energy.

Energy can be transformed into another type of energy. For example, the potential energy can be transformed into kinetic energy.

Also, energy is not created, nor destroyed.

Answer:

The following is not true about the Law of Conservation of Energy:

A. It states that the total energy in the universe keeps increasing.

8 0
3 years ago
Read 2 more answers
What is a mixture, element or a compound
Lelechka [254]
A mixture is a substance made by mixing other substances together.
6 0
3 years ago
Other questions:
  • which of the following small bodies are the hardest to tell apart because they are made of similar materials ? A . dwarf planets
    9·2 answers
  • An object weighing 4 newtons swings on the end of a string as a simple pendulum. At the bottom of the swing, the tension in the
    9·2 answers
  • DO not answer unless you actually now how to do this!!
    5·1 answer
  • Which scientific law is also known as the law of inertia? PLZ HELP ASAPPPPPPPPP!!!
    10·2 answers
  • How do different forces act on a system
    14·1 answer
  • Which of the following makes a good electrical insulator? Why? a.Glass, because it is slippery and smooth. b. Glass, copper and
    11·1 answer
  • The blue laser in a blue ray DVD player is 405nm laser in vacuum. The aser strikes a quartz crystal with index of refraction 1.4
    9·1 answer
  • A student measured the volume of three rocks. The diagram above shows the
    5·1 answer
  • Which of the following is true about inertia
    5·1 answer
  • You are feeling like spaghetti. Although normally only about 2 meters tall, you are now about 25 meters long. (How fortunate, if
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!