# Methods for improved accuracy in unsteady aerodynamics (MIAU)

*Johan Hammar, Ciarán O'Reilly and Gunilla Efraimsson*

In the aeronautical/vehicle industry, simulation of flows is essential in order to predict the vehicle performance and behavior. In these simulations turbulence modeling is included. An accurate prediction of the turbulence gives e.g. a better basis for drag prediction and aero-acoustic analysis, which affects the vehicle design. This projects looks at computional methods which are more efficent in terms of the number of discretisation points needed for a given accuracy. In particular, a wave expansion method (WEM) is investigated as this is an efficient discretization technique which is used for wave propagation problems. The method uses fundamental solutions to the wave operator in the discretization procedure and will thus proasduce accurate results at two to three points per wavelength.

**Publications:**

[1]
J. Hammar, C. J. O'Reilly and G. Efraimsson.
"Simulation of aerodynamically generated noise propagation using the wave expansion method,"
* 22nd AIAA/CEAS Aeroacoustics Conference, * 2016.

[2]
J. Hammar.
"A Wave Expansion Method for Aeroacoustic Propagation,"
* Licentiate thesis, KTH Royal Institute of Technology, * 2016.

[3]
J. Hammar, C. J. O'Reilly and G. Efraimsson.
"Simulation of aerodynamically generated sound using hybrid aeroacoustic methods,"
* 10th European Congress and Exposition on Noise Control Engineering, Euronoise, * pp. 521-526, 2015.