Riassunto analitico
Brake killer test is a destructive test performed to calculate the reliability of the brake disks. These tests were carried out for five braking cycles, where each cycle has four periods. They are braking period, rest period, acceleration period and nominal velocity period. During the development phase of new brake unit, replacing this test with the numerical approach through CFD analysis will give us possibility to test various design in short period of time and this method is also cost efficient.
The main objective of the project is to find the methodology to perform the virtual brake killer test using the CFD tools, and to achieve the higher heat transfer in the considered brake system. The front brakes of the next gen tractor have considered as a test case to validate the methodology.
In this project two different CFD approach has been used, moving particle simulation (MPS) method and finite volume method (FVM). The first method has been used to perform the oil flow analysis, which is used to measure oil flowrate through the solid parts.
After the oil flow analysis, thermal analysis has carried out using finite volume method. The simulation was set up with the multiphase-VOF model with oil and air phases, implicit unsteady time model with different timestep, based on the period of the braking cycle. Then the conjugate heat transfer was used to simulate the heat transfer between solids and fluids and moving reference frame was used to simulate the rotation of the disks and fluid around the rotating disks. From the simulation we can be able to get the thermal energy stored by each disk, and their temperature at the end of each cycle.
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