Experimental Study On The Convective Heat Transfer Characteristics Of The Internal Pin Fin Channel Of High-speed Train Brake Disc

In recent years,the development of high-speed railway technology makes the train running faster and faster.The train braking system has become an important issue in the safe operation of high-speed trains,and a key technology to be solved.In the process of braking,the brake disc produces a lot of heat energy through friction,brake discs are required to have high heat dissipation.If the brake disc does not dissipate heat in time,it is easy to cause hot crack in the brake disc,etc,affecting the safe operation of trains.Therefore,this paper mainly studies the convective heat transfer characteristics of the internal pin fin channel of high-speed train brake disc,it is of great significance for the safe braking of the train.The main contents of this paper include: the average convective heat transfer characteristics of the internal channel of the pin fin brake disc was obtained by using the analogy principle of naphthalene sublimation heat transfer and mass transfer.It was found that the average Nusselt number of the internal channel of the brake disc increases with the increase of the Reynolds number.In addition,in order to study the effect of the internal pin fin parameters of the brake disc on the average convective heat transfer characteristics,by changing the parameters of the internal pin fin of the brake disc in this paper,the corresponding experimental specimens were designed to study the influence of the diameter,the number and the height of the pin fin on the convective heat transfer characteristics of the brake disc.The results are as follows:(1)Under the same Re,keeping the height and the number of the internal pin fins constant,the diameter of the internal pin fin of the brake disc is smaller,the average Nusselt number of the brake disc is larger.(2)When the height and the diameter of the internal pin fin of the brake disc are same,under the same Re,the more the number of the internal pin fins is,the smaller the average Nusselt number is.(3)If the diameter and the number of the internal pin fins are constant,under the same Re,the greater the height of the internal pin fin of the brake disc is,the greater the average Nusselt number is.(4)The average Nu of the internal channel of the pin fin brake disc increases with the increase of Re.