Numerical Simulation For Performance Of A Diesel Engine Used In Altiplano Locomotives

After the development of more than 100 years, diesel engine, with its highest thermal efficiency, great adaptability and broad power range, has been widely used in sectors of industry, agriculture, transportation and national defense. When diesel engine runs at high altitude, it is difficult to guarantee that the engine can serve normally as desired, due to its significant performance deterioration. At present, the experiment-only approaches which obtain the performances of diesel engine under different atmospheric conditions are usually difficult. Whereas the computational simulation method can be an alternative way with its fast computation speed, short debug period, low research cost and acceptable accuracy. However, systematical researches on engine running-process under different altitudes can be hardly seen in either domestic or international open reports. It is because short of the research in this area, design and development on plateau engines are directly affected.In this paper, present research job on running performances and characteristics of multi-cylinder engine, especially the diesel engine running on high altitude, was analyzed. The necessity and feasibility of power improvement and decrease the specific fuel consumption was also discussed. In this research, an entire locomotive engine model of 16 cylinders was set up. Based on the engine model, running process under different atmospheric condition was simulated by numerical method, the calculation results at different running speeds and different sea altitudes were compared and some improve methods of "power recover" in plateau area for this engine were presented. The improvements include two ways: one is by modification of turbocharger; another is to take advantage of optimization valve timing.On account of geographical and environmental inconvenience, it is hard to setup satisfying physical parameters and acceptable testing conditions for on-site plateau experiment and simulation test bed. The computational simulation method on the other hand, can compensate the deficiency of that, to some extent. Therefore, the computational simulation method can be a guide for optimum design of plateau diesel engine.