Fundamental and Applied Studies in Chemical Reacting Flows

化学反应流程的基础与应用研究

• 批准号: RGPIN-2018-03807
• 负责人: Kostiuk, Larry
• 金额: $ 4.66万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=712626
• 关键词: Fundamental; Applied; Studies; Chemical; Reacting

In keeping with the objectives of a Discovery Grant, the proposed work is program-based. It contains fundamental and applied research, as well as broadly addressing two core motivations for studying chemical reacting flows. This research is aimed at advancing the understandings needed to control and manage: (A) the environmental impacts of the combustion of hydrocarbon resources; and, (B) the rates of conversion of chemical energy to thermal energy associated with combustion processes. Project A Decarbonization of Natural Gas for Heating Applications: The world is transitioning away from fossilize fuels that primarily store their energy in the form of carbon (e.g., coal and oil, and to a lesser degree natural gas), which introduces “new” carbon dioxide into the atmospheric when it is burned, to a system with net-zero carbon cycle. A process is being explored, specifically for heating applications, to see if the elements in the alkanes in natural gas can be economically partitioned through thermal decomposition in a zero-oxygen environment into black carbon and hydrogen. These components can then be easily separated based on their density, capturing the carbon as a solid while sending the hot hydrogen off for combustion where its products are needed at their typical temperatures. The net result is that twice as much natural gas is processed as originally burned for the heating application, but there are no carbon dioxide emissions. This project also involves the characterization of the captured black carbon to see if it has value for tires, rubber, paint, inks, or electrodes. Project B - Role of Unsteadiness in Modelling Premixed Turbulent Flames at High Damkohler Numbers: Our phenomenological understanding the interactions between unsteady flows and burning rates is not as well developed as for steady flames. Most practical flames are turbulent, so they are rife with unsteadiness. The objective of this study is to ensure that these unsteady effects are properly accounted for in modelling the burning rate of premixed flames. Of particular interest is the way that flames respond to flow features that have time scales of the same order as the flame chemistry. As those time scales approach each other the response of the flame's heat release are profoundly affected in terms of phase lag and amplitude. Depending on the equivalence ratio of the reactants this may occur at frequencies as low as 100 Hz. Consequently, non-direct numeric simulations (i.e., large eddy simulations and G-equation models) miss the time (and hence location) and amplitude of heat release. The approach we are taking is to develop flame transfer functions based on simple direct numeric simulations and make models available to those studying complex turbulent flows. Taken collectively, this research will contribute to more a responsible and environmentally sustainable use of hydrocarbon fuels.

为了与发现补助金的目标保持一致，拟议的工作是基于方案的。它包含基础和应用研究，以及广泛解决研究化学反应流的两个核心动机。这项研究的目的是促进控制和管理所需的理解：（A）碳氢化合物资源燃烧的环境影响;（B）与燃烧过程相关的化学能转化为热能的速率。 项目A用于供暖应用的天然气脱碳：世界正在摆脱主要以碳形式储存能量的化石燃料（例如，煤和石油，以及在较小程度上的天然气），它在燃烧时将“新的”二氧化碳引入大气，以实现净零碳循环。目前正在探索一种工艺，特别是用于加热应用，以确定天然气中烷烃中的元素是否可以通过在零氧环境中热分解而经济地分离成黑碳和氢。然后，这些组分可以根据它们的密度很容易地分离出来，将碳捕获为固体，同时将热氢送去燃烧，在那里需要其典型温度下的产物。最终的结果是，加工的天然气是最初用于加热应用的天然气的两倍，但没有二氧化碳排放。该项目还涉及对捕获的炭黑进行表征，以确定其是否对轮胎，橡胶，油漆，油墨或电极有价值。 项目B -在高Damkohler数下模拟预混湍流火焰时非定常的作用：我们对非定常流和燃烧速率之间相互作用的现象学理解不如对定常火焰的理解那样完善。大多数实际的火焰都是湍流的，所以它们充满了不稳定性。本研究的目的是确保这些不稳定的影响是正确的占在模拟预混火焰的燃烧速率。 特别令人感兴趣的是火焰对具有与火焰化学相同的时间尺度的流动特征的响应方式。当这些时间尺度彼此接近时，火焰的热释放的响应在相位滞后和振幅方面受到深刻影响。取决于反应物的当量比，这可以在低至100 Hz的频率下发生。因此，非直接数值模拟（即，大涡模拟和G方程模型）错过了热释放的时间（以及因此的位置）和幅度。我们正在采取的方法是开发火焰传递函数的基础上简单的直接数值模拟，使模型可用于那些研究复杂的湍流。 总的来说，这项研究将有助于更加负责任和环境可持续地使用碳氢燃料。