Vortex generator modeling and its application to optimal control of airflow in inlet

Sammanfattning: This dissertation deals with the development of the vortex generator model and its use for the optimization study of vortex generator flow control in high-offset-ed inlets. In the first part, the overview of use of vortex generators and their mechanism is outlined. Both the application form the existing aircraft as well as laboratory studies are reviewed. The second part contains four papers. The first paper deals with the development, verification and validation of the vortex generator model in Navier-Stokes code. Although primarily meant to be used in inlets, the validation of the model was carried out in case of high-lift system by comparing pressure coefficient to the experimental data. Second paper deals with development of the inflow and outflow mass flow boundary conditions for Navier-Stokes codes. Newly designed mass flow boundary conditions were compared to existing mass flow boundary conditions. Special attention was paid to flows under condition of choking. Third paper deals with the Design of Experiment optimization study of the vortex generator flow control in the RAE M2129 inlet with two sets of five geometrical parameters. The aim is to reduce the inlet flow distortion and increase pressure recovery. The parameters of optimal vortex generator setup were then used to design a vortex generator flow control in more realistic inlet for a UAV. Fourth paper deals with testing of vortex generator flow control in the UAV inlet under different flight conditions. In order to be able to find appropriate parameters of flow in inlet, entire UAV with prescribed value of the mass flow was calculated. It was found that the proposed vortex generator installation malfunctioned when at conditions corresponding to the high altitude flight conditions. A new configuration with double number of vortex generators was then tested and at proven being stable. Triangular vortex generators were tested also.