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Unified modelling framework of sub- and super- critical injection dynamics

亚临界和超临界注射动力学统一建模框架

基本信息

批准号：
EP/P012744/1
负责人：
Konstantina Vogiatzaki
金额：
$ 12.84万
依托单位：
University of Brighton
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2017
资助国家：
英国
起止时间：
2017 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=EP%2FP012744%2F1
关键词：
Unified modelling framework sub super

项目摘要

Despite many previous (mostly experimental) efforts to characterise super-critical injection conditions, they still remain a challenging fluid dynamics problem due to the multi-scale, multi-phase character of the complex physical phenomena that governs it. This proposal aims to offer a systematic approach towards a better understanding and prediction of the transition of sub- critical to super- critical injection phenomena, combining novel state of the art simulations with experiments already performed by the University of Brighton and Sandia National Laboratories for diesel engine conditions. The model will include real gas effects and target both primary and secondary atomization regions at the limit of transition between sub- critical to super- critical conditions. Such an approach is currently lacking from commercial and open source simulation tools. The new framework will be developed within Large Eddy Simulations (LES) and will be based on the extension of ideas also used in probabilistic modelling of flame interfaces (surface density approaches). The major strength of the approach is that it does not include any a priori region-dependent assumptions for the liquid-gas volume fraction in the computational cells, and bypasses the spherical vision of the liquid structures that compose the spray. Thus, it can be applicable both to the near-nozzle and the dilute spray areas, and represent both sharp (as in the case of sub- critical injection) and diffused (more representative of super-critical conditions) interfaces. Our suggested numerical models have the potential to capture the underlying physics of the phenomena even at extreme thermodynamic conditions and therefore can play the role of "virtual experiments", providing valuable access to flow areas and conditions where real experiments face limitations. The numerical framework that will be presented in the proposed research aspires to lead to the creation of the new generation of equipment design tools that will be available to both academic and non-academic sectors and will facilitate the cost effective design of novel high pressure injection systems. Moreover, the outcomes of the research will be disseminated to the academic community through publications in high impact journals and national and international conferences as well as an outreach workshop. These could change the way we currently view the modelling of multiphase problems not only for automotive application but for other disciplines involving super-critical fluids.

尽管此前许多尽管超临界注入条件的研究（主要是实验性的）已经取得了很大进展，但由于控制超临界注入条件的复杂物理现象的多尺度、多相特征，它们仍然是一个具有挑战性的流体动力学问题。结合了布莱顿大学和桑迪亚国家实验室针对柴油发动机条件已经进行的新的最先进的模拟实验。该模型将包括真实的气体效应，并以在亚临界到超临界条件之间的过渡极限处的初级和次级雾化区域为目标。这种方法目前缺乏商业和开源模拟工具。新的框架将在大涡模拟（LES）中开发，并将基于火焰界面概率建模（表面密度方法）中也使用的想法的扩展。该方法的主要优点是，它不包括任何先验的区域依赖的假设，在计算单元中的液体-气体体积分数，并绕过组成喷雾的液体结构的球形视觉。因此，它可以适用于近喷嘴和稀释喷雾区域，并代表尖锐（如在亚临界喷射的情况下）和扩散（更代表超临界条件）界面。我们建议的数值模型有可能捕捉到的现象，即使在极端的热力学条件下的基本物理，因此可以发挥“虚拟实验”的作用，提供有价值的访问流动领域和条件的真实的实验面临的限制。将在拟议的研究中提出的数值框架旨在创建新一代设备设计工具，这些工具将可用于学术和非学术部门，并将促进新型高压喷射系统的成本效益设计。此外，研究成果将通过在影响力大的期刊、国家和国际会议以及外联讲习班上发表的文章传播给学术界。这些可能会改变我们目前看待多相问题建模的方式，不仅适用于汽车应用，而且适用于涉及超临界流体的其他学科。