Optimization Design for Water Jacket of 4G24 Gasoline Engine

Abstract

Use CFD (Computational Fluid Dynamics) technique to simulate the water jacket of 4G24 gasoline engine is an effective way to look into the internal flow status of the water jacket. After calculation analysis, it is found that part of regional flow rate is too low in the cylinder head and block water jacket, where is easy to form dead areas. The HTC (Heat Transfer Coefficient) on cylinder block intake side is low, and needs to be improved. Total pressure loss of water jacket surface is too large. Based on above calculation analysis, as optimized schemes, place a baffle at the inlet in front of the cylinder, add some holes on the top of cylinder block by use of clear sands holes to guide water from cylinder block to cylinder head and form better water flow lines. After optimization, dead areas were eliminated, heat transfer effect of cylinder block intake side is improved. Total pressure loss of water jacket surface is basically unchanged or slightly increased. By comparing some optimized schemes, place a baffle at inlet is found to be the best one.

CFD modelling on flow field characteristics of engine cooling water jacket and its cooling performance improvement based on coolant transport path analysis method

“…Li et al 80 used 3D CFD simulation to study the inner flow of water jacket and suggested that the cooling system’s performance can be optimized by changing the speed, pressure and distribution of the HTC in the cooling jacket. Zhang et al 81 used CFD technique to obtain internal flow status of water jacket and eliminated flow dead areas by placing a baffle at inlet in front of the cylinder. Lien et al 82 used CFD to investigate the flow inside a cooling water jacket of 400c.c four-stroke single-cylinder and established a transparent water jacket model for validation of simulation model.…”