Abstract
Aircraft noise is an issue of enormous environmental and technological impact. Projected growth in significant development of quiet modern engines has brought renewed attention to the non propulsive component of aircraft noise. Flow induced noise is one of the major contributors in the noise generation in various industrial applications. Trailing edge noise is an important component of aircraft airframe noise, in particular during landing and approach. Moreover trailing edge is also a noise generation mechanism for wind turbine rotor blades and helicopter blades. Due to stronger regulations with respect to noise pollution, the implementation of wind turbines will tend to hamper. To ensure its further development, it is important to reduce this noise mechanism and therefore requires better modeling.
Computing trailing edge noise is complex since it is inherently connected with turbulence. The trailing edge noise is caused by the interaction of turbulent structures with the trailing edge. Large Eddy Simulations (LES) has proven to be a reliable method for the calculation of aero-acoustic problems. Although it provides sufficient accuracy and is less expensive than DNS, the higher computational cost compared to Reynolds Averaged Navier Stokes (RANS) makes it less attractive. A combination of sufficient accuracy and cost savings is found in the hybrid RANS-LES approaches. Herein the boundary layers are solved in full RANS mode. The price to pay with such models is found in the uncertainties in the transition zone between both modes.
The project aims at trailing edge simulations of NACA 0012 airfoil using RANS in OpenFOAM and ANSYS FLUENT©. The reference pressure taken is 2 x 10-5 Pa which corresponds to a sound pressure level (SPL) value of 0 dB. The graph of SPL v/s location and SPL v/s curve length has been plotted for angle of attack of 00 and 70.