Dynamics Simulation And Dynamic Stress Analysis Of Crankshaft On6L21/31Medium Speed Marine Diesel

People have higher demand for performance of modern diesel engine which tends tothe way of high power density, low pollution, low emission, low noise and highreliability.Cam wear emphasis and valve train poor stability were exited in Medium-speeddiesel engines of6L21/31Marine.In this article,the simulation models of diesel engine andits valve train were set up using AVL-BOOST and AVL-TYCON softwareseparately.Combine calculation was done to optimize the valve timing and cam profile.Themain work is as follows:(1) The numerical model of6L21/31Marine Medium-speed diesel engine has beenbuilt by AVL-BOOST software, and the simulation results were compared withexperimental data to verify the correctness of the model. On the basis,optimal valve timingwas got by analyzing the impact of intake delayed angle,exhaust advanced angle and valveoverlap on the performance of the engine.(2) The kinematic and dynamic simulation models of the intake and exhaust valve trainof6L21/31Marine Medium-speed diesel have been built by AVL-TYCON software. Thevalve train models of before and after phase optimization was calculated.The kinematics anddynamics performance should be got.And cam profile has been optimized.Through the study on the front several aspects,6L21/31Marine medium diesel’soptimum valve timing can be got at900r/min,100%load conditions.The intake advanceangle is42°CA, intake closing angle is51°CA,exhaust advance angle is42°CA, exhaust lateangle is57°CA. The diesel performance have been improved at the optimum valvetiming.By the optimization of cam profile,valve train kinematics and dynamics have beenimproved.The maximum cam contact stress and jerk have been reduced. Valve train workmore smoothly.Also the fullness factor has been increased.