Numerical Investigation of Compressibility Effects in Turbulent Boundary Layers

Abstract

The current proposal describes the research plan associated to the overseas internship (BEPE) of student Luiz A. C. A. Schiavo. Mr. Schiavo is currently a PhD. student in the School of Mechanical Engineering at University of Campinas, FEM-UNICAMP, funded by a FAPESP Scholarship, process No. 2014/07623-6. The internship period abroad should be held at Lawrence Livermore National Laboratory, LLNL, located in Livermore, CA, USA. During this period, Luiz will work under the supervision of Dr. Britton J. Olson who is currently a Computational Physicist at LLNL. Dr. Olson has extensive expertise in the fields of computational fluid dynamics, turbulence, compressible flows, numerical methods, high-order schemes and immersed boundary methods. All these topics are related to the present research proposal. The main objective of the present work concerns the investigation of compressible turbulent boundary layers, focusing on a detailed research of compressibility effects on flow statistics using a combination of immersed boundary methods (IBM) and high-order compact schemes. The effects of compressibility in boundary layers including wall curvature will be analyzed in order to investigate the turbulence anisotropy and also changes in production, transport and dissipation mechanisms in Reynolds stresses and turbulent kinetic energy budgets. A better understanding of the relevant mechanisms responsible for turbulent kinetic energy and Reynolds stress balances can be used to provide important information for the development of accurate turbulence models based on the Reynolds stress transport equations. Furthermore, in the present work, novel numerical techniques will be employed to perform turbulent flow simulations involving boundary layers and shock waves. Accurate shock capturing methods such as the Localized Artificial Diffusivity, LAD, will be employed with directional artificial properties. In order to investigate the compressibility effects in turbulent boundary layers, 3-D simulations will be carried out. These simulations will be performed at LLNL under the supervision of Dr. Olson. Note that the internship period abroad was already planned in the doctoral project approved by FAPESP (Process No. 2014/07623-6). One should also mention that Dr. Olson was at UNICAMP as a visiting researcher in February of 2015 to initiate a collaboration with the current research group. His visit was sponsored by the American Physical Society (APS) and a student of Prof. Wolf's group has successfully concluded a MSc. BEPE internship in 2015 at LLNL. The present proposal is important in the context of Mr. Schiavo's PhD. research, currently supported by FAPESP and it will also foster collaboration between UNICAMP and LLNL.