This work is focused on study of transonic buffet around a NACA 0012 airfoil with a dynamic direct method using URANS equations for numerical simulations.

Introduction

1

Abstract

This work is focused on study of transonic buffet around a NACA 0012 airfoil with a dynamic direct method using URANS equations for numerical simulations.

Introduction contains a short description of buffet phenomenon accompanied by state of the art of its onset prediction available in literature, followed by an extended abstract to present in more detail examples of conducted analyses.

Chapter 1 presents building of the model with details on computational field and mesh; furthermore, it contains setup parameters to reach validation and a comparison between results given by two different kinds of grid shape and their validation.

Chapter 2 shows a further validation on model rescaled with comparison between pressure coefficient obtained from CFD and that given by tests in particular conditions.

Other themes developed in this section are setups of made analyses and methods of studying results obtained, giving a logical thread common to all simulation series performed.

Chapter 3 focuses on results obtained at Mach number equal to 0.76, giving all obtained results in detail. At the end of this section is presented an overview of simulations made at that Mach number and a further study of located buffet onset condition.

Chapter 4 presents data obtained for Mach equal to 0.775, again in detail, location of buffet onset condition and in the end an overview of results and a further study of buffet onset point.

Chapter 5 in the same way of previous chapters, shows results obtained for Mach equal to 0.80.

Chapter 6 presents results at Mach 0.816 and incidence angle different from zero.

Chapter 7 shows obtained data of analyses at fixed incidence of zero degrees and Mach number beyond 0.80.

Chapter 8 contains comments on results, giving an overview of located buffet onset points accompanied by frequencies involved and innovations highlighted by this work.

A short appendix focused on symbology used and strategy to extrapolate setup data for

simulation and a reference section complete this thesis.