Abstract: Aiming at the cooling of the compact engine cylinder head‚the flow distribution test of the cooling water which flows in the chamber of the transparent cylinder head was performed by using the flux and pressure measurement and the coloring agent method．The2D flow field of the cooling water in the complicated chamber was then obtained‚ and some improvement was made on the improper structure of the chamber．Furthermore‚the3D flow fields of the cooling water in the chambers of the actual cylinder heads before and after the improvement were obtained by means of the computational fluid dynamic （CFD） software FIRE．A comparative analysis was finally carried out between the test results and the CFD results．It is indicated that‚after the improvement‚the flux and pressure distribution in the water chamber is proper‚and the eddy and dead zone decrease．Meanwhile‚the flow direction and the flux of the cooling water obtained by the numerical simulation accord well with the experiment and observation results．

Key words: engine cylinder head, cooling water flow, CFD analysis, experimental research