The theory and application of eulerlets

Chadwick, EA; Christian, JM; Kapoulas, A; Chalasani, K

Abstract

Consider a fixed body in a uniform flow field in the limit as the Reynolds number approaches infinity and the flow field remains steady. Instead of using standard techniques and theory for describing the problem, a new method is employed based upon the concept of matching two different Green’s integral representations over a common boundary, one given by approximations valid in the near-field and the other by approximations in the far-field. Further novelty arises from the choice of a near-field, that is, the Euler flow matched to an Oseen flow far-field. This entails introducing and defining eulerlets that are Green’s functions of the Euler equation. One important consequence of the model is the presence of a new Euler wake velocity not captured in standard models. This has a constant unchanging downstream profile and arises from the matching to the far-field Oseen wake velocity. It is then shown how this representation reduces to classical inviscid ideal flow aerodynamics when applied to flow past aerofoils and wings. It is also shown how it reduces to slender body flow theory. Finally, the formulation is tested on uniform flow past a circular cylinder for mean-steady subcritical laminar flow and turbulent flow. The inviscid impermeability boundary condition is used, the drag coefficient is specified, and a constant distribution of drag eulerlets is modeled. The forward flow separation and pressure drop in the wake are captured and compare favorably with experiment. The future expectation is the modeling of multiple general shaped bodies.

Citation

Chadwick, E., Christian, J., Kapoulas, A., & Chalasani, K. (2019). The theory and application of eulerlets. Physics of Fluids, 31(4), 047106. https://doi.org/10.1063/1.5088132

• Journal Article Type: Article
• Acceptance Date: Apr 2, 2019
• Online Publication Date: Apr 23, 2019
• Publication Date: Apr 23, 2019
• Deposit Date: May 1, 2019
• Publicly Available Date: Apr 23, 2020
• Journal: Physics of Fluids
• Print ISSN: 1070-6631
• Electronic ISSN: 1089-7666
• Publisher: AIP Publishing
• Volume: 31
• Issue: 4
• Pages: 047106
• DOI: https://doi.org/10.1063/1.5088132
• Publisher URL: https://doi.org/10.1063/1.5088132
• Related Public URLs: https://aip.scitation.org/journal/phf
• Additional Information: Access Information : This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Physics of Fluids and may be found at the Official URL link above.