Shockwave boundary layer interaction (SBLIs) is a flow behaviour when a transonic or supersonic shockwave reaches the near wall fluid that is at a relatively lower speed and energy level. Such interactions might be detrimental to aircraft performances. Thus, understanding and designing methods to control SBLIs is of great importance in modern engineering. The main objective of control is to energize the low-momentum boundary layer to weaken the shock strength and separation it induces. Different configurations can be categorized into active and passive methods. This project focuses on the simulation of herringbone or converging-diverging riblets structure`s effects on SBLIs. It is a new kind of bio-inspired passive. Previous experiments have reported an attenuation of the flow separation in SBLIs using such devices, but the exact control mechanics has not been fully revealed yet. The numerical simulation of flow over herringbone riblets conducted in this project has been set up to model a previously conduced wind tunnel experiment. Two-equations k~Îµ RANS model and an enhanced wall treatment method have been used within the commercial ANSYS-Fluent CFD code. The simulation gives a clear average supersonic flow field around the riblets region. A large-scale secondary flow roll structure is clearly seen from results, which is similar to that previously reported in laminar flow simulations. The downstream boundary layer as well as the shockwave-induced separation have been suppressed. A reasonable match between solution and experiment oil-line results is seen. With these results achieved, a qualitative conclusion between flow effect and riblets geometry parameters is drawn. In the final chapter, potential further work and research directions are discussed.
|Date of Award||31 Dec 2022|
- The University of Manchester
|Supervisor||Timothy Craft (Supervisor) & Shan Zhong (Supervisor)|