Determining Mass of Moment of Inertia for Flywheel in IC Engine

In summary: Shigley goes into a bit more detail.C_s=\frac{\omega_2 - \omega_1}{\omega}\omega = \frac{\omega_2 + \omega_1}{2}E_2 - E_1 = \frac{I}{2} \left[(\omega_2 - \omega_1)(\omega_2 + \omega_1)\right]E_2 - E_1 = C_s I \omega^2OK , so the equation is C_s=I*w^2*C where I=mass moment of
  • #1
marquez
5
0
i have diagram of the turning moment in flywheel in internal combustion engine , i want to determine the mass of moment of inertia of the flywheel needed to keep speed fluctuation < or equal 1.5% at engine speed 560 rpm ?

http://img534.imageshack.us/img534/1765/57306264.jpg [Broken]
 
Last edited by a moderator:
Engineering news on Phys.org
  • #2
From my book "Fundamentals of Machine Elements" 2nd Edition by Hamrock, Schmidt, and Jacobsen, the equation for the mass moment of inertia can be calculated from knowledge of the speed fluctuation and kinetic energy. Here is how the authors state it.

"By knowing the desired coefficient of fluctuation for a specific application, obtaining the change in kinetic energy from the integration of the torque curve, and knowing the angular velocity, the mass moment of inertia required can be determined."

Ke = I*w^2*C

where

ke = kinetic energy
I = mass moment of inertia
C = coefficient of fluctuation
w = average omega value (angular velocity)

I = ke / C*w^2

Since the two equations are dependent upon each other you can use an iterative procedure to obtain the two results. I haven't done this myself so I don't know how fast the results will converge or if they will at all. If that doesn't work then use the integration of the torque curve.

Thanks
Matt
 
  • #3
Shigley goes into a bit more detail.

[tex]C_s=\frac{\omega_2 - \omega_1}{\omega}[/tex]

[tex]\omega = \frac{\omega_2 + \omega_1}{2}[/tex]

[tex]E_2 - E_1 = \frac{I}{2} \left[(\omega_2 - \omega_1)(\omega_2 + \omega_1)\right][/tex]

[tex]E_2 - E_1 = C_s I \omega^2[/tex]
 
  • #4
from my book also "https://www.amazon.com/dp/019515598X/?tag=pfamazon01-20" in page : 680 : many of the torque - displacement functions encountered in practical engineering situations are so complicated that they must be integrated by approximate methods. like Simpson's or Trapezoidal rule

but i need more directly method or equation to solve that faster than integration

Thanks matt
 
Last edited by a moderator:
  • #5
FredGarvin said:
Shigley goes into a bit more detail.

[tex]C_s=\frac{\omega_2 - \omega_1}{\omega}[/tex]

[tex]\omega = \frac{\omega_2 + \omega_1}{2}[/tex]

[tex]E_2 - E_1 = \frac{I}{2} \left[(\omega_2 - \omega_1)(\omega_2 + \omega_1)\right][/tex]

[tex]E_2 - E_1 = C_s I \omega^2[/tex]

OK , maybe i use this equations after use integration to get value from graph

Thanks
 

What is the purpose of determining the mass and moment of inertia for a flywheel in an IC engine?

The mass and moment of inertia of a flywheel are important parameters to consider in the design of an IC engine. They affect the engine's overall performance, including its ability to maintain a steady rotation and store energy. By accurately determining these values, engineers can optimize the engine's design for improved efficiency and durability.

How is the mass of a flywheel determined?

The mass of a flywheel can be determined by physically weighing the flywheel or by using mathematical calculations. To calculate the mass, the density of the material, its dimensions, and any added components must be known. This information is then plugged into the appropriate equations to determine the flywheel's mass.

What is moment of inertia and why is it important for a flywheel in an IC engine?

Moment of inertia is a measure of an object's resistance to changes in its rotation. In the context of a flywheel in an IC engine, it refers to the flywheel's ability to maintain a steady rotation and store energy. A higher moment of inertia means the flywheel can store more energy and maintain a more consistent rotational speed, leading to smoother engine operation.

What factors affect the mass and moment of inertia of a flywheel in an IC engine?

The mass and moment of inertia of a flywheel can be affected by several factors, including the material it is made of, its shape and dimensions, and any added components such as gears or pulleys. The placement of these components and the overall design of the flywheel can also impact its mass and moment of inertia.

How can the mass and moment of inertia of a flywheel be optimized for an IC engine?

To optimize the mass and moment of inertia of a flywheel for an IC engine, engineers must carefully consider the design and materials used. By choosing lightweight and durable materials, minimizing added components, and strategically placing them, the mass and moment of inertia can be optimized for the specific needs of the engine.

Similar threads

Replies
2
Views
2K
  • Classical Physics
2
Replies
49
Views
1K
Replies
26
Views
1K
Replies
5
Views
2K
  • Mechanical Engineering
Replies
5
Views
1K
  • Mechanical Engineering
Replies
3
Views
7K
  • Mechanical Engineering
Replies
2
Views
3K
  • Mechanical Engineering
Replies
8
Views
2K
Replies
2
Views
1K
Replies
2
Views
2K
Back
Top