High Fidelity, Multiscale Modeling For Eco-Design in Aviation

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The proposed research program broadly aims to develop predictive, multiscale models and high fidelity design tools for eco-friendly aviation. Reducing the environmental impact, while maintaining economic profitability, is perhaps the most significant technical challenge faced by aerospace and transportation industries, as well as the energy sector.******The increasingly stringent restrictions on emission levels require the development of revolutionary technologies. Computational tools will be of significant importance for the design of such new technologies.******The overarching and long-term goal is to contribute toward innovative and unconventional designs to reduce aircraft noise and engine pollutants. In the short term, the proposed program focuses on introducing multiscale, phenomenological models, and high fidelity computational tools on unstructured-grid solvers to predict aircraft noise and combustion byproducts such as CO2, CO, NOx, and soot. These models are in particular developed for Large Eddy Simulation (LES) of reacting and nonreacting flows. ******In the short term, the research program will be focused on developing accurate and mathematically consistent models, and numerical schemes that are specifically suitable for implementation in unstructured-grid solvers. Unstructured grids allow for significant flexibility to represent complex, industrial-type geometries. However, many accurate subgrid models such as Approximate Deconvolution Models have only be applied to structured-grids. The extension and verification of such models for unstructured grids is one of the main goals of this program. ******In the long term the research will be directed toward using the developed computational tools to obtain further insight into the role of coherent structures in turbulent flows with respect to the formation and radiation of pollutants and noise. Our hypothesis is that changes in the topology of turbulent eddies significantly affect sound radiation by turbulent shear flows and pollutants formation in turbulent reacting flows. Therefore, one can control and suppress noise and pollutants formation by intelligently changing the topology of turbulent eddies through the use of properly designed nozzles, and mixers.******We will employ mathematical tools such as Algebraic Topology and Knot Theory to postprocess results from Direct Numerical Simulations (DNS) and LES of turbulent reacting and nonreacting flows to obtain insight about the role of turbulent eddies topology. The results are expected lay the foundation for new topological theories and models in turbulence, computational aeroacoustics, and turbulent combustion. It is also expected that this program would pave the path for effective design methodologies of noise suppression devices such ash microjets and lobed mixers, and new concepts for low-emission combustion chambers.