A numerical investigation of s-duct flows with boundary-layer ingestion

The essence of this paper is to report the computational research conducted to further NASA's study of active flow control systems for a flush­-mounted inlet with significant boundary-­layer ingestion (BLI). In conjunction with a NASA-­sponsored research grant, the aim is to further accumulate knowledge and insight on the effectiveness of flow control devices in reducing circumferential distortion. Using Computational Fluid Dynamics (CFD), this study seeks to validate wind tunnel results recorded by the NASA Langley Research Center. After numerically reproducing experimental data, the future goal is use CFD to simulate the interaction between the inlet and turbofan stage. This study focused on NASA's air jet flow control devices, specifically a 16-­jet version referred to as “configuration­-10”. The accuracy and validity of the numerical solutions was dependent on their ability to match the following experimental values: mass flow rate through the S-­duct, mass flow ratio, pressure measurements along the center line, and distortion coefficient at the aerodynamic interface plane. Three computational grids, containing 6.5, 30.5, and 36.9 million nodes, were constructed for the numerical simulations. The three grids varied in solid modeling techniques and grid element packing. Time limitations prevented the inclusion of results for the largest computational grid. Yet for the two smaller computational grids, the “Tenasi” flow solver was able to calculate valid numerical solutions for the “baseline” case (no jet flow) as well as low jet mass flow rate cases. High jet mass flow rate cases noticeably strayed from the experimental distortion measurements. Even though the numerical solutions did not replicate the experimental values for all mass flow ratio cases, this research significantly contributed to the knowledge and understanding of vorticity, flow characteristics, and distortion reduction for the BLI flush­mounted inlet. The CFD results provide visual representations of the changing flow characteristics as the jet mass flow rate is increased, in addition to flow interaction with intrusive experimental measuring devices. It is felt that better agreement with high­mass flow rate experimental cases can be calculated by numerically refining the jet boundary conditions and jet flow parameters. Overall, this paper reveals the steps taken in achieving early success in computationally verifying experimental data, and it discusses current actions being made towards further validating the numerical solutions.

Grantor dc:publisher

University of Tennessee at Chattanooga

Author dc:creator

• Johnson, Benjamin C.

Contributors dc:contributor

• Webster, Robert S.
• Anderson, W. Kyle; Briley, W. Roger
• College of Engineering and Computer Science

• Fluid dynamics -- Computer simulation

Licence

• https://rightsstatements.org/page/InC/1.0/?language=en

Language dc:language

English, eng

Repository record dc:identifier

https://scholar.utc.edu/theses/305

OAI identifier oai:identifier

oai:scholar.utc.edu:theses-1445