Simulation Of Flow Characteristics On Lubricating System Of A V Type Multi-cylinder Diesel Engine

The lubrication system is one of the important systems of a diesel engine, and its workperformance has great effects on the working reliability and power of a diesel engine. Byusing the one-dimensional hydraulic mechanical performance simulation softwareAMESim, a V turbocharged multi cylinder diesel engine simulation model was establishedand calibrated in this paper. This paper studied the diesel engine lubrication system flow atrated working condition and different working condition, bearing clearance, ambientpressure and oil temperature.The distribution of the lubrication system at rated working condition was studied inthis paper. The results showed that: among these key components, the entrance pressure ofthe connecting rod bearing was the highest; the amount of fuel from the injection pistoncooling nozzle was the largest; the entrance pressure and injection quantity of these pistoncooling nozzles was obviously different, and these in the left row were significantly higherthan that of right row.The distribution of the lubrication system at different working condition was studied inthis paper. The results show that: when the engine speed increased, the pressure of the keypoints and the entrance of each bearing rised rapid to become gradually flatten, finally fellslightly, the same as the flow rate within the bearing. The minimum oil film thickness of thebearing increased with the increase of speed; when the main bearings and connecting rodbearings load increased, the entrance pressure and the flow rate of each bearing changedvery little, and the minimum oil film thickness of the injection pump camshaft and valvetrain camshaft bearing remained unchanged, while the minimum oil film thickness of themain bearings and connecting rod bearings decreased obviously.This paper studied the effect of the bearing clearance on the distribution of thelubrication system. The results showed that: when a group of bearing clearance increased,the pressure of the key points and the entrance of each bearing decreased evidently, and theflow rate of the main oil pipe of the engine increased slightly. The flow rate of this group ofbearing increased significantly, and their minimum oil film thickness increased slightly,while the flow rate of the other three groups reduced obviously, and the minimum oil filmthickness stayed unchanged. Comparing the four groups of bearing clearance effect on theflow distribution of the lubrication system, the degree of influence from large to small in turn was the main bearings, connecting rod bearings, injection pump camshaft bearing,valve train camshaft bearing.This paper studied the effect of the environmental pressure and oil temperature on theflow distribution of the lubrication system. The results show that: when the ambientpressure reduced from0.1MPa to0.04MPa, the pressure of the key points and the entranceof each bearing reduced slightly, and the flow rate of the main oil pipe and bearing changedlittle, meanwhile, the minimum oil film thickness of these bearings remained unchanged;when the oil temperature increased from30℃to120℃, the pressure of the key points andthe entrance of each bearing declined slowly to become a rapid decline, and the flow rate ofthe main oil pipe rised rapid to become gradually flatten, meanwhile, the minimum oil filmthickness of these bearings declined, and the flow rate of them increased.