Torque required to overcome inertia and friction on a flywheel

Click For Summary
SUMMARY

The discussion centers on calculating the torque required to overcome inertia and friction for a flywheel with a diameter of 565mm and mass of 210 kg, reaching a speed of 710 rev/min in 16 seconds. The coefficient of friction between the shaft and bearing is 0.3, which must be incorporated into the torque calculations. The relevant equations include T = Iα (Torque = Inertia x Angular acceleration) and τ = μω (Friction torque = coefficient of friction x angular velocity). The participant seeks clarification on integrating the coefficient of friction into the torque equation and deriving a second-order differential equation for angular acceleration.

PREREQUISITES
  • Understanding of rotational dynamics and torque calculations
  • Familiarity with the moment of inertia formula I = (mr²)/2
  • Knowledge of angular acceleration and its relation to torque
  • Basic grasp of differential equations in the context of physics
NEXT STEPS
  • Research how to incorporate friction into torque calculations in rotational systems
  • Learn about deriving second-order differential equations in rotational dynamics
  • Study the relationship between angular velocity and torque in flywheel systems
  • Explore numerical methods for solving differential equations related to angular motion
USEFUL FOR

Mechanical engineers, physics students, and anyone involved in the design and analysis of rotational systems, particularly those working with flywheels and torque calculations.

Aldebo
Messages
2
Reaction score
0
∂hi all. I sort of understand this question but not fully so here it goes:

A shaft carrying a flywheel of diameter 565mm and mass 210 kg is required to run at a speed of 710 rev/min. If the working speed is to be reached in 16 seconds from rest and the coefficient of friction between shaft and bearing is 0.3, determine,

The torque required to overcome inertia and friction .

so far I've worked out T=IA (Torque = Inertia x Angular acceleration), however where is the coefficient of 0.3 involved and how.

any help will be much appreciated Relevant equations

T=Ia ∴ I=(mr²)/2

w2=w1+at ∴ a=(w2-w1)/t

However I'm not sure where the coefficient of friction is involved in all this, maybe a separate equation I don't know
 
Physics news on Phys.org
any help would be much appreciated.
 
Friction torque is defined by τ = μω, analogous to daming force F = cv. So μ has units of N-m-s/radian.

Knowing that, what is the 2nd order differential equation relating angular acceleration θ'' to net torque, and can you simplify it by making the independent variable ω instead of θ? Then solve the eq. for ω(t), set t = 16s, and solve for required applied torque.
 

Similar threads

  • · Replies 6 ·
Replies
6
Views
4K
  • · Replies 3 ·
Replies
3
Views
3K
  • · Replies 18 ·
Replies
18
Views
4K
Replies
10
Views
5K
  • · Replies 6 ·
Replies
6
Views
4K
  • · Replies 2 ·
Replies
2
Views
9K
  • · Replies 11 ·
Replies
11
Views
5K
Replies
1
Views
2K
  • · Replies 10 ·
Replies
10
Views
8K
  • · Replies 60 ·
3
Replies
60
Views
7K