Numerical Simulation Of Heating And Cooling Process Of Road Surface In Special Region And Environment

Accelerated Loading Test is an effective way of simulating actual environment and load of the road, and research in pavement material property and failure mechanism to solve practical engineering problems. Full scale accelerated loading system could duplicate same-size scale of the actual road structure, eliminates the small proportion to speed up the loading of the boundary effect of the system. Therefore, it has been widely adopted worldwide nowadays. Previous researches have shown that the road materials are very sensitive to extreme temperature, so accelerated loading experiments should precisely control over the road surface temperature for experimental road. The full scale accelerated loading systems currently running abroad are open systems and not yet possible to control the road surface temperature."Special geographical environment of structural materials testing device" of this project is an enclosing accelerated loading test track. The air temperature and road surface temperature can be controlled in this test track. As a result, Air temperature and pavement temperature control system are very important in the test system.Because there are not many previous work and material can be used in this project, so numerical simulation could provide the theoretical basis and data support for design and construction in air temperature and pavement temperature control system. In this thesis, commercial CFD software Ansys Fluent and integrated optimization software Ansys DesignXploer were used to simulated accelerated test subgrade surface air heating or cooling process and also the system design parameters and air supply pattern were optimized.First of all effect on road surface average temperature and temperature uniformity for different layout size and height in blowing inlet and outlet were studied. Second, propose feasibility analysis for further raise in road surface temperature uniformity. Last but not least, propose a swing-type blowing design. In order to optimize the result, we use pavement surface temperature uniformity as indicator for hot and cold air with different physical properties to determine the optimal outlet swing angle and swing cycle. The numerical simulation results show that this proposal could lead the temperature uniformity of the road meets the design requirement of3K, and easy to be applied in the construction projects.