Study On Thermal Transmission Of Radiator Of Enigneering Vehicle And Selcetion Of Structure

The radiator performance problem has plagued by domestic engineering vehiclemanufacturers, as one of the largest engineering machine manufacturer in our countryXuGong has focused on optimization of radiator performance and selection method.Due to the microscopic parameters needed in engineering computation cannot beobtained directly, the calculation precision cannot meet the requirement of engineering.This paper is based on the XuGong’s XGSX04-58radiator selection project, by usingnumerical analysis in combination with engineering calculation analyzed heat transfermechanism of straight fin and slit fin, came up with a feasible method of radiatorselection. In project development, the radiation efficiency of XGSX04-58radiator wasimproved effectively. The main work of this thesis is:(1) According to requirement of FLUENT, knowledge of computational fluiddynamics and numerical heat transfer, established mathematical model, chose discretescheme and solution of discrete equation. Microscopic evaluation of radiatorperformance standards was introduced, and they are heat transfer factor and frictionfactor. According to numerical simulation environment and results, simplifiedengineering calculation method, and heat dissipating capacity and air pressure loss wereobtained as macroscopic evaluation of radiator performance standards.(2) According to project actual investigation, introduced the production process ofplate-fin radiator briefly. Proceeded qualitative analysis of performance of straight finradiator and slit fin radiator. Established geometric model and computational domain ofstructural unit of four radiators provided by project, built mesh, encrypted the mesh ofkey parts, and verified the mesh independence. the size and number of mesh wereultimately determined.(3) In this paper proceeded numerical simulation on structure unit of four radiatorsby using FLUENT. heat transfer and air flow in straight and slit fin at different inletvelocity were analyzed separately. Combined with field synergy principle, heat transferand air flow at the same inlet velocity in straight fin and slit fin were compared.Correlation of heat transfer factor, friction factor and Reynolds number were obtainedby fitting, correlation of heat dissipating capacity, air pressure loss and inlet velocitywere obtained by engineering calculation and fitting. The best structure was selectedaccording to simulation and calculation. (4) Wind tunnel experimental was carried out with the help of XuGong institute.The principle of wind tunnel test, measurement accuracy of the sensor and experimentalmethod were introduced. Following results can be summarized by comparing theexperimental result and simulation result: The heat transfer factor and friction factor’serror between numerical simulation and experimental were13%and14%; the heatdissipating capacity and air pressure loss’s error were6%and7%, which shows thatsimulation and calculation results were true and reliable. In normal altitude, whencooling water inlet amount was205L/min and the air inlet velocity was4m/s thecooling power of selected radiator was120kW, air pressure loss was130Pa, which canfulfill the technical requirement. This project results show: Radiator selection methodcombined numerical simulation with engineering calculation has high accuracy, shortenthe design cycle, has practical significance for radiator selection for engineering vehiclemanufacturers.