In-cylinder studies of direct injection gasoline in the optical engine

2015年，Brunel成功地获得了EPSRC的大笔设备拨款，建立了一个卓越的光学发动机和缸内测量技术中心。如下图所示，这个耗资100万英镑的新设施包括一台新的单缸直喷汽油光学发动机和一套高速激光测量设备。该发动机有一个完整的熔融石英光学衬里，用于直接可视化整个进气和压缩冲程的缸内流动和燃油喷射过程。额外的光学访问是由一个光学活塞冠安装在一个细长的钛活塞，将滑动上下光学衬垫。气缸盖的设计可以容纳中央安装和侧面安装的喷油器，从而可以获得喷雾导向和壁导向分层装药。与其他大学目前使用的气缸内测量激光系统不同，布鲁内尔大学的新设备将采用两个独立的高速高功率固态激光器和高速图像增强摄像机，以高达10,000fps的速度进行循环分辨的气缸内流量、燃油喷射和混合物形成测量。这样的设施在英国将是独一无二的，将允许基础研究和应用开发工作进行高效率，高性能和低排放的汽车用直喷汽油发动机。作为新设备的结果，一个新的博士项目已经建立，进行直接喷射汽油在光学发动机的缸内研究。该项目将由EPSRC DTP和位于伯明翰的长安英国联合支持，长安英国的母公司长安汽车是中国第四大汽车制造商。长安英国负责长安汽车在中国的下一代汽油直喷发动机的开发。伦敦布鲁内尔大学拥有欧洲最大的内燃机研究中心之一。在过去的几年里，长安和布鲁内尔之间进行了多次互访，以确定双方共同感兴趣的合作研究和开发活动。自2015年10月以来，Mohan Peethambaram先生作为布鲁内尔大学的兼职学生开始了他的博士学位。他的博士研究工作将集中在CFD发动机模拟在GDI发动机上的发展和应用。该博士项目的目的是研究直喷式汽油机的缸内流动、燃油喷射、混合气形成和燃烧起爆过程。特别是，喷射器设计和喷射策略对混合物形成过程的影响将通过先进的激光测量技术进行研究，包括流动和喷雾之间的相互作用，喷雾和壁面之间的相互作用，以及喷雾特性。实验结果将用于验证CFD计算结果，并提高用于新型直喷汽油机开发和优化的三维CFD发动机模拟能力。该项目将由伦敦布鲁内尔大学的赵华教授和Lionel Ganippa博士指导，由长安英国公司的朱博士指导。博士项目计划于2016年10月开始，为期36个月。

BackgroundIn 2015, Brunel has been successful in getting a large EPSRC equipment grant to set up a centre of excellence in in optical engines and the in-cylinder measurement techniques. As shown by the image below, the new £1.0 Million facility comprises a new single cylinder direct injection gasoline optical engine and a suite of high speed laser measurement equipment. The engine has a full length optical liner of fused silica for direct visualisation of the in-cylinder flow and fuel injection process throughout the intake and compression strokes. Additional optical accesses are provided by an optical piston crown mounted on an elongated titanium piston that will slide up and down the optical liner. The cylinder head is designed to accommodate both the centally mounted and side mounted injectors so that both spray guided and wall guided stratified charge can be obtained. Unlike the current laser systems for in-cylinder measurements in use at other universities, the new facility at Brunel will feature cycle resolved in-cylinder measurement of flow, fuel injection and mixture formation at speeds up to 10,000fps by means of two separate high speed and high power solid state lasers and high speed image intensified video cameras. Such facility will be unique in UK and will allow both fundamental research and applied development worked to be carried out on the high efficiency, high performance and low emission direct injection gasoline engines for automotive applications. As a consequence of the new facility, a new PhD project has been set up to perform in-cylinder studies of direct injection gasoline in the optical engine. The project will be jointly supported by the EPSRC DTP and ChangAn UK in Birmingham, whose parent Company, ChanAn Automotive, is the 4th largest automotive manufacturer in China. ChangAn UK are responsible for the development of next generation gasoline direct injection engines for ChangAn Automotive in China. Brunel University London have one of the largest internal combustion engines research centres in Europe. Over the last few years, a number of mutual visits have taken place between ChangAn and Brunel to identify the collaborative research and development activities which are of mutual interest to both parties. Since October 2015, Mr Mohan Peethambaram has started his PhD degree as a part-time student at Brunel. His PhD research works will be focused on the development and application of CFD engine simulation to the GDI engine.Outline of PhD projectThe aim of the PhD project is to study the in-cylinder flow, fuel injection, mixture formation and combustion initiation processes in a direct injection gasoline engine. In particular, the effect of injector design and injection strategy on the mixture formation process will be investigated by means of the advanced laser measurement techniques, including the interactions between flow and sprays, spray and wall interactions, as well as the spray characterisation. The experimental results will be used to validate the CFD calculations and improve the capability of the 3-D CFD engine simulation being used in the development and optimisation of the new direct injection gasoline engines. Project Management and FinanceThe project will be supervised by Prof. Hua Zhao and Dr Lionel Ganippa at Brunel University London and advised by Dr Zhu at ChangAn UK. The PhD project is planned to start in October 2016 and last for 36months.