Analysis And Optimization Of Heat Exchange In HK280Grader Underhood Thermal Management

Grader is the engineering machinery widely used in road traffic，airport constructionand other project in the flat ground for land leveling，bulldozing and fabric etc。The demandfor grader and construction machinery is on increase each year with the increment of theinfrastructure construction.The manufacturers are focusing on engineering machinery ofhigh efficiency, low consumption and comfort with the increased competition in themarket.Grader work in low speed and heavy load condition and work long hours in anatmosphere of high temperature, high dust density.As a result, the nacelle cooling system isin full load facing a severe test.On the study of heat dissipation for under-hood, thedistribution of flow field and temperature field should be taken into account in involve theeffect to heat dissipation from the arrangement of more than one heat sink.There are lots ofheat sources in grader nacelle.As a result it is difficult to get the flow direction andtemperature in under-hood use test methods.At the same time, the size of large engineeringmachinery make traditional wind tunnel test hard to make.Application of CFD technology in automobile product development research andsubsequent analysis increasing each year as the more perfect of computational fluiddynamics and computational heat transfer theory, the continuous development of computerhardware and software, combined with the demand with the demand brought by the rapidupgrading of automobile technology.It is using CFD method, this article in view of the grader nacelle cooling performanceproblems, analysis engine room arrangement of flow field and radiator for cooling analysisthe effect of flow field and arrangement of radiator to the heat dissipating performance ofcooling packages, based on the study of flow field and temperature field.Provide thetheoretical basis for the further study of under-hood thermal management. First of all, establish a three-dimensional mathematical model based on the size of areal car and a wind tunnel which will simulate the environment.Discrete the area withstructure and unstructured grid, strictly structure hexahedron grid will be used in coolingpackage.Set the boundary condition and choose the simulation model according to theproject, get the physical model used in numerical test.Then simulate the flow field and the in grader nacelle and heat exchanger in coolingpackage.Analysis the flow field and temperature field in the grader nacelle under the ratedpower when the maximum fan speeds, and focuses on the effect of the arrangement ofradiator in cooling package to the performance of the cooling package.Finally, proposed two optimization methods according to the simulation results.Thefirst is adjust the size and location of air inlet and the second is change the shape of thetransmission oil cooler.It’s improve the heat dissipation ability of the cooling packageaccording to the simulation results.