Study On The Ignition Delay Characteristics Of N-butanol

China's economy and vehical industry has developed very quickly in the past few years,which result in the amount of the energy that we need is increasing.At the same time,the vehical exhaust become very seriously.As a result,China's economy will be restricted by the energy crisis and environment ploblem.There are two ideas to resolve the problem,on the one hand,research new engine technology,on the other hand,study the engine alternative fuel. n-butanol has been inportant research point for its perfect property.Ignition delay is closely related to the engine's property,the research of the n-butanol ignition delay can help us to understand the fuel's combustion characteristics.Firstly,we research how the boundary conditions will influence the n-butanol ignition delay in the constant volume combustion bomb. The selected boundary conditions are as follows,pressure before ignition is0.8MPa,1.2MPa and1.6MPa, initial temperature is150?,200?and250?, the excess air coefficient is0.42,0.6,0.8,1.0,1.2,1.6,2.0and2.4.From the research,we can see that if the temperature or pressure increases,the n-butanol ignition delay time will increase,however,if the excess air coefficient increases, the n-butanol ignition delay time will drop firstly and then increase, the n-butanol ignition delay time will get its minimum value when the excess air coefficient is0.8.Secondly,we compare the ignition delay time of n-butanol and93#gasoline. The selected boundary conditions are as follows,pressure before ignition is0.8MPa,1.2MPa and1.6MPa, initial temperature is150?,200?and250?, the excess air coefficient is1.0.From the reseach we find that the n-butanol ignition delay time is longer than that of93#gasoline.Based on the research result and experience formula theory,we set up an experience formula to compute the n-butanol ignition delay time,which is suitable for the constant volume combustion bomb.We also compare the compute value and the experiment data,the compare result shows that the build experience formula is accurate.Lastly,we use AVL FIRE to simulate the n-butanol ignition delay time to resolve the experiment research's finite ploblem and limitations.We build geometric model and divide grid mesh based on the constant volume combustion bomb's structure,then we define the initial parameter and boundary conditions,at last,we select the compute model.Through compare the simulate value and experiment data,we find that the compute model's simulate value is reasonable.Base on the compute model,we expand the boundary conditions to simulate the n-butanol ignition delay time,the simulate result shows that if the temperature or pressure increases,the n-butanol ignition delay time will increase,however,if the excess air coefficient increases, the n-butanol ignition delay time will drop firstly and then increase, the n-butanol ignition delay time will get its minimum value when the excess air coefficient is0.8?0.9.The simulate verdict prove the experment's accuracy.