缸内直喷汽油机多孔喷油器喷雾特性试验研究

为了研究缸内直喷汽油机多孔喷油器的喷雾特性,建立了定容喷雾试验装置,对不同环境压力和不同喷油压力条件下的自由喷雾和碰壁喷雾过程进行了拍摄,分析了壁面距离和壁面倾角对喷雾特性的影响.研究发现:多孔喷油器与传统的旋流式喷油器的喷雾特性存在较大差异.多孔喷油器的喷雾锥角受环境压力影响较小;随着环境背压的增大,贯穿距离和喷雾锥角呈现先增大后减小的特点;喷雾锥角随着喷射压力的提高略有增加.在碰壁喷雾发展过程中,不同环境压力下喷雾油束与壁面接触面积接近;随着壁面距离的增加,碰壁喷雾高度递减,碰壁后的喷雾高度存在波动;随着壁面倾角的增大,碰壁喷雾高度和增大.在壁面倾角的增大过程中,影响碰壁喷雾半径的因素较多

Spray Characteristic of Multi-hole Injector for In-cylinder DI Gasoline Engine

In order to study the spray characteristic of multi-hole injector on in-cylinder direct injection gasoline engine,the constant volume spray experimental device was built.The processes of free spray and impingement wall spray were shot under the conditions of different ambient pressure and injection pressure.The influences of wall distance and wall inclination on spray characteristic were analyzed.It was found that there existed a big difference of spray characteristic between the traditional swirl injector and the multi-hole injector.The spray cone angle of multi-hole injector was little influenced by ambient pressure.With the increase of ambient pressure,the spray penetration and spray cone angle first increased and then decreased.With the increase of injection pressure,the spray cone angle slightly increased.In the process of impingement wall spray,the contact areas between spray beam and wall were close under different ambient pressures.With the increase of wall distance,the spray height after wall impingement decreased step by step and fluctuated.With the increase of wall inclination,the summation of spray height increased.During this process,the spray radius after wall impingement was influenced by many factors and showed a complex variation.The above research provided the theoretical reference for multi-hole injector design and combustion chamber match.