| How to generate detonation wave is the basis of the research on both the pulse detonation engine and the rotating detonation engine.As the main part of the detonation engine ignition system,the detonation tube has become the focus of the research.In this paper,by means of numerical simulation,the effects of the structure of the detonation tube,ignition energy and ignition mode on the initiation were studied systematically.The research object is detonation tube with a total length of 200mm,diameter of 10mm.Numerical simulation of the combustion process was performed using k-epsilon turbulence model and single step chemical reaction model under the condition of premixed stoichiometric ratio H2-Air with initial pressure of 1atm and initial temperature of 300K.First of all,from the perspective of the reflection superposition of the disturbance wave and the Lewis number,the combustion process in the detonation tube was analyzed in stages.Then,to study the movement of triple point in the detonation wave front,a detailed summary of the detonation wave periodicity and a description of the change rule of the detonation wave front in time and space were proposed.In order to investigate the influence of ignition source on the flame development in the detonation tube,the idea of changing ignition energy is proposed.The effects of constant-pressure variable-temperature ignition and constant-temperature variable-pressure ignition were investigated respectively.From the perspective of ignition energy,the relationship between the ignition temperature,ignition pressure and the development of the flame in the detonation tube is obtained.ignition,put forward research ideas to change the ignition energy,were investigated in the constant pressure variable temperature and constant temperature and variable pressure ignition scheme of ignition scheme,from the angle of ignition energy,get the relationship between the ignition temperature,ignition pressure and detonation tube flame development situation.By comparison,the conclusion was drawn that the combustion process is more sensitive to the change of ignition pressure.In the analysis of the conventional ignition scheme,it was found that the leading pressure field would cause the backflow region behind the obstacle,and then the twice ignition method is proposed.By comparing and analyzing the results of numerical simulation,the primary ignition scheme and the twice ignition scheme of different positions were discussed from the aspects of pressure disturbance,chemical reaction rate and flame position.It was found that the effect of the two ignition in the initial stage is better than that of the latter. |
