Study On Optimization Design Of Combustion Chamber Structure For High Intensified Diesel Engines

Since the advent of internal combustion engine technology,it has been widely applied and rapidly developed,making a huge contribution to industrial development.However,the accompanying energy and environmental pollution issues cannot be ignored,and many scholars have invested a lot of time and energy in reducing the energy consumption and emissions issues of internal combustion engines.As a container for combustion reactions,the structure of the combustion chamber has a significant impact on processes such as fuel injection,fuel gas mixing,and turbulent gas flow in the cylinder,thereby affecting the power and economy of diesel engines.This article uses CFD numerical simulation calculations to optimize and analyze the combustion chamber structure of a highly enhanced diesel engine.An in cylinder combustion simulation model is established to simulate and analyze the results of different combustion chambers,and the influence of combustion chamber structure on diesel engine performance is obtained.This article uses GT Power software to establish a one-dimensional combustion calculation model for diesel engines,and obtains the initial and boundary conditions of the three-dimensional combustion calculation model.Then,AVL FIRE software is applied to establish a three-dimensional combustion model of a diesel engine,and performance tests of a single cylinder engine are used to verify and analyze the distribution results of physical quantities such as cylinder pressure and temperature,indicated power,and pollutant emissions in the cylinder.Afterwards,parameterized modeling was conducted on the combustion chamber of a highly strengthened diesel engine,dividing the combustion chamber profile into four main structures.Combustion chamber design was carried out for different structures and simulation calculations were completed.The combustion calculation results were processed to analyze the impact of different combustion chamber structures on diesel engine performance.Analyze the sensitivity,contribution rate,and optimization effect of multi-objective optimization based on the calculation results of combustion chambers with different structures.It was found that the structures such as pit radius,necking distance,and aperture ratio have a significant impact on the performance of the highly strengthened diesel engine studied in this article.Analyzing the changes in combustion chamber volume,it was found that increasing the combustion chamber volume can effectively improve engine performance.Select appropriate structural factors and block structure optimization plans to obtain an overall optimization plan for the combustion chamber,and optimize the overall structure of the combustion chamber.Multi objective optimization and single objective optimization analysis were conducted on the calculation results of the combustion chamber of the optimization plan.Optimization plan 32 is the optimal plan for multi objective optimization.The evaluation value of the multi objective optimization of this plan increased by 78.56%,the indicated power increased by 1.94% compared to the original machine,NO emissions increased by 9.6%compared to the original machine,and Soot emissions decreased by 83.8% compared to the original machine.Optimization Plan 23 is the optimal solution for single objective optimization,with an increase in indicated power of 2.2% compared to the original machine and a decrease in Soot emissions of 83.6% compared to the original machine.This article mainly analyzes the influence of combustion chamber structure on the combustion and emission characteristics of diesel engines,obtains optimized combustion chamber structure,improves diesel power performance indicators,and significantly reduces Soot emissions,providing technical methods and data support for the optimization of highly strengthened diesel engine combustion chamber structure.