Numerical investigation of instability mechanisms and transition to turbulence in laminar separation bubbles through isotropic disturbances

• Grant number: 24/00149-9
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: May 01, 2024
• End date: April 30, 2027
• Field of knowledge: Engineering - Aerospace Engineering - Aerodynamics
• Principal Investigator: Elmer Mateus Gennaro
• Grantee: Renan Trevizan de Melo
• Host Institution: Faculdade de Engenharia. Universidade Estadual Paulista (UNESP). Campus Experimental São João da Boa Vista. São João da Boa Vista , SP, Brazil

Abstract

This project is focused on investigating free-stream turbulence (FST) and hydrodynamic instability mechanisms, aiming to understand the transition to turbulence in laminar separation bubbles. The physics of separated flows is complex, as separation and transition are intimately intertwined, and the presence of external disturbances or forcing leads to additional difficulties, given that different instability mechanisms may compete. To address this challenge, the project proposes introducing isotropic disturbances of FST with varying intensities. Through direct numerical simulations (DNS), the physical mechanisms influencing the interaction between separation and transition in separation bubbles will be investigated. The in-depth study of these interactions can offer significant insights into the dynamics of separation bubbles under FST conditions, such as those found in free flight. This enhanced understanding has the potential to directly impact the design and optimization of aerospace vehicles, as well as other applications where flow control is crucial. The project also intends to contribute to the scientific literature, providing a deeper comprehension of instability and transition mechanisms in separated flows. The results are expected to be applicable in improving efficiency and performance across a variety of engineering contexts, paving the way for innovations in design and flow technology. (AU)