Mixing at transcritical conditions

在跨临界条件下混合

• 批准号: 530178493
• 负责人: Professor Dr.-Ing. Andreas Bräuer
• 金额: --
• 依托单位: Institut für Thermodynamik der Luft- und Raumfahrt (ITLR)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/530178493?language=en
• 关键词: Mixing; transcritical; conditions

Mixing processes of two fluid compounds are transcritical, when the initial states of the two fluids (before mixing) do not allow a definite prediction on whether the mixing will take place in a single- or in two-phases. Though mixing at transcritical conditions is widely used in propulsion systems and diesel motors, in the novel CryoPower recuperated split cycle engine (RSCE) and high pressure processes for particle generation, we do not have a clear understanding about the relevance of the different mechanisms (two-phase vs single-phase mixing) involved into mixture formation. As a consequence, there is currently no consensus about how transcritical mixing can be modelled best in order to reliably reflect the relevant mechanisms. The data-availability on quantitative experimental insights into transcritical mixing processes is rare. Therefore, the main aim of this proposal is the experimental provision of quantitative mixture compositions and temperature couples along real transcritical mixing path trajectories (work packages 2 & 3), which in the future can serve as quantitative reference for modelling approaches. The comparison of real vs theoretical mixing path trajectories (work packages 4 & 5), will reveal to which extent (i) the departure from thermodynamic equilibrium, (ii) the degradation of a phase interface and (iii) the different rates of energy and mass transport due to the additional thermal and mass diffusion, have to be regarded in the models for the description of transcritical mixing processes. The quantitative composition/temperature-data (spatially resolved) will be provided via the combination of various complementary optical measurement techniques. To a large extend the project is based on the utilization of already existing either composition or temperature data, which through this proposal will be supplemented to high-value couples of correlated compositional and temperature data.

当两种流体的初始状态（在混合之前）不允许对混合是否将在单一或双重范围内进行混合时，将两种流体化合物的混合过程（在混合之前）的初始状态（在混合之前）是跨危。尽管在跨临界条件下的混合在推进系统和柴油机中广泛使用，但在新型的冷冻温度恢复的拆分周期发动机（RSCE）和颗粒产生的高压过程中，我们对不同机制（两阶相VS单相混合）的相关性没有明确的了解。结果，目前尚无共识，即如何对跨批评混合进行最佳建模以可靠地反映相关机制。对跨临界混合过程的定量实验见解的数据可用性很少。因此，该提案的主要目的是沿实际的跨临界混合路径轨迹（工作包2和3）的定量混合物组成和温度夫妇的实验提供，将来可以作为建模方法的定量参考。实际VS理论混合路径轨迹（工作包4和5）的比较将揭示（i）（i）与热力学平衡的不同程度，（（ii）相位界面的降解以及（iii）因其他热量和质量扩散而导致的能量和质量运输的不同速率，在额外的热和质量扩散中，必须考虑到跨批评的过程。定量组成/温度数据（空间解析）将通过各种互补光学测量技术的组合提供。大扩展项目基于已经存在的成分或温度数据的利用，通过该提案将补充为相关组成和温度数据的高价值夫妇。