Enter the heat flux, brake on time, density of disc material, specific heat capacity, thermal conductivity, and ambient temperature into the calculator to determine the maximum brake disc temperature.
Brake Disc Temperature Formula
The following equation is used to calculate the maximum Brake Disc Temperature.
BDTm = (0.527 * q * Sqrt (t)) / Sqrt(p*c*k) + Tamb
- Where BDTm is the maximum Brake Disc Temperature (C)
- q is the heat flux (watts/m^2)
- t is the brake on time (s)
- p is the density of the brake disc (kg/m^3)
- c is the brake disc specific heat capacity (J/kg/K)
- k is the brake disc thermal conductivity (W/(m*K))
- Tamb is the ambient temperature (C)
What is a Brake Disc Temperature?
Brake disc temperature refers to the heat generated during the braking process in a vehicle. When a driver applies the brakes, the friction between the brake pads and the brake discs produces heat due to the conversion of kinetic energy into thermal energy.
This heat is transferred to the brake discs, causing them to become hot.
The significance of brake disc temperature lies in its impact on braking performance and safety. High brake disc temperatures can lead to several undesirable outcomes. Excessive heat can cause the brake discs to warp or distort, leading to uneven contact with the brake pads.
Elevated brake disc temperatures can also lead to brake fade. Brake fade occurs when the heat generated during prolonged or intense braking causes the brake pads and discs to overheat, reducing their ability to generate friction.
How to calculate Brake Disc Temperature?
Example Problem:
The following example outlines how to calculate a brake disc temperature.
First, determine the heat flux. In this case, the heat flux is 10000 watts/m^2.
Next, determine the brake on time. These brakes are on for 5 seconds.
Next, determine the density of the disc. This disc has a density of 7000 kg/m^3.
Next, determine the specific heat of the disc. This is found to be 500 J/kg/K.
Next, determine the thermal conductivity of the brake. This averages 58 W/(m*k) for cast iron.
Next, determine the ambient temperature. The ambient temperature if 40C.
Finally, calculate the Brake Disc Temperature using the formula above:
BDTm = (0.527 * q * Sqrt (t)) / Sqrt(p*c*k) + Tamb
BDTm = (0.527 * 10000 * Sqrt (5)) / Sqrt(7000*500*58) + 40
BDTm = 40.82 C
