Application Of Nanofluid Heat Transfer In Cylinder Water Jacket Block Of Engine

As the development of industry,traditional pure liquid heat transfer medium couldn't meet the engine cooling requirements in some special work condition.If the cooling liquid takes the heat little,some engine parts will be over heat,so the economy and reliability of engine will be affected.Nanofluid as a new kind of high thermal conductivity heat-transfer medium,it owns the advantage of the high thermal conductivity,good lubrication and good stabilization.This thesis used the changed original experinmental apparatus to do the experiment of nanofluid heat-transfer.Then based on the strengthening heattransfer character of nanofluid and applied nanofluid to cylinder water jacket of engine.CFD numerical simulation method was employed to analyse the nanofluid application value in industry.On the heat-transfer characteristics of nanofluid aspect,this paper has prepared four kinds of CuO/glycol nanofluids(0.25%,0.50%,0.80%,1.50%).Firstly,join the nanoparticles in the glycol-water(50%glycol and 50%water).Secondly,with decentralized means of add dispersant?join the dispersant in the fluid and ultrasonic.Finally,put the prepared nanofluid into the circulatory experimental system and test the heat-transfer coefficient and the pressure.The experimental results show that the heat-transfer coefficient of nanofluid becomes higher than that of pure fluid at the same Reynolds number and increased with the increasing of the mass fraction of CuO nanoparticles.But the results also indicate that the pressure of nanofluid increased by the mass fraction increase.When the mass fractions of CuO/glycol nanofluid at the 0.50%,the pressure enhance 8.23% and the heat-transfer coefficient enhance 23.18%.Because of nanofluid as a new high thermal conductivity cooling liquid,this thesis choosed four cylinder engine as the model.Basing on the nanofluid heattransfer characteristics,applied FLUENT software to simulate the four kinds of fluids in the cylinder block water jack and calculated the flow distribution,temperature distribution and pressure distribution so that analyze the useful value in the industry.And result show that the heat-transfer is better with the increasing concentration of CuO/glycol nanofluid,and in the high concentration the heat-transfer performance of CuO/glycol nanofluid is bright,on the contrary in the low concentration the CuO/glycol nanofluid is almost as same as glycol-water.This thesis provided an important basis for which nanofluid as a new kind of high thermal conductivity heat-transfer medium,and nanofluid applied in engine cooling system may provide a new effective approach for engine design to meet much higher heating load in future.