Prediction Model for Brake-Drum Temperature of Large Trucks on Consecutive Mountain Downgrade Routes Based on Energy Conservation Law

Table 1

Parameter values.

Parameter name	Symbol	Unit	Value
Number of axles			6
Weight of brake drum		kg	60
Heat capacity of brake drum		J/(kg·°C)	545
Gross truck weight		t	30,35,40,45,50
Gravitational acceleration		m/s^2	9.8
Height difference		m	200,300,400,500,600
Slope			0.035,0.04,0.045,0.05,0.055
Speed		km/h	50,55,60,65,70
Coefficient			6
Coefficient			0.068
Slope length		km	3,4,5,6,7,8,9,10
Drag coefficient			0.8
Windward area of the truck		m^2	8.75
Air density		N•s^2•m^−4	1.2258
External surface of the brake drum		m^2	0.45
Initial temperature of the brake drum		°C	50
Environmental temperature		°C	25
Emissivity of the brake drum			0.65
Radiance of the black body		W/(m^2•K^4)	5.6710^−8