Heat produced from Brake Pad Friction material?

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Discussion Overview

The discussion centers around calculating the heat generated from the friction between brake pads and discs in a car brake system. Participants explore various methods and equations related to energy conversion and heat generation in this context.

Discussion Character

  • Exploratory
  • Technical explanation
  • Mathematical reasoning

Main Points Raised

  • One participant presents an equation for the force transmitted to the disc, incorporating pressure, area, and the coefficient of friction.
  • Another participant suggests that the conversion of kinetic energy into heat can be calculated if the car's velocity and mass are known.
  • A different viewpoint emphasizes that work done by the brakes, calculated as force times distance, directly correlates to heat generation, introducing the concept of power as force times velocity.
  • There is mention of using the kinetic energy formula, but concerns are raised about the variability of mass and the inclusion of other energy losses, such as air drag.

Areas of Agreement / Disagreement

Participants present multiple approaches to calculating heat generation, indicating that there is no consensus on a single method. Different perspectives on the relationship between force, work, and energy conversion remain unresolved.

Contextual Notes

Participants express uncertainty about the assumptions involved in their calculations, such as the fixed nature of mass and the effects of external factors like air drag.

heiroglif
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Hi all,

My model of a car brake system is intended to monitor the rate at which heat increases/decreases as friction between a brake pad and disc increases.

My equation for the force transmitted to the disc is:

Force = (δP x Ac) x μb

where δP is the pressure generated at the master cylinders

Ac is the area of the caliper pistons

and μb is the coefficient of friction of the brake pad material.

how can i find the heat generated fromt his equation, any suggestions?

thanks in advance
 
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I am no expert but the brakes convert kinetic energy into heat. So if you know the car's velocity and mass, you can figure out how much kinetic energy will be converted to heat.

Also, if you know how much force the brake is applying and the distance over which it is applied, you can figure out how much energy was converted to heat.
 
Now that you know the force F. Just imagine the car is in its stop and you still push the brake: no heat. The work is calculated as : W=FS , then dW=FdS <==> dW/dt=FdS/dt (S is the distance, v: velocity) or power P=Fv. All the work is converted into heat so with that equation, you calculate exactly the heat generated by the brake.
You can also easily compute the heat by : E=mv^2/2. But the mass in this equation is not fix, and the energy E also includes the friction caused by air drag.
 
Guys thanks a lot for your replies, its much appreciated, i will study what you have said, and if i have any more issues, will post them here...thanks :)
 

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