An accurate noise prediction is important in order to reduce noise emission significantly and to prevent expensive after-design treatments. This study aims to examine the aerodynamics and aeroacoustics performance of an open system consisting of an axial fan and a heat exchanger where hybrid method incorporating CFD (Computational Fluid Dynamics) and CAA (Computational Aeroacoustics) is used to predict the noise behavior. The hybrid model method used consists of three steps. Firstly, the flow is computed by means of flow-computed fluids and the pressure fluctuations are obtained. This is followed by the acquisition of acoustic signals from these fluctuations and the attainment of a sound pressure level approach with the FW-H (Ffowcs Williams & Hawkings) model. Unsteady flow field of the air channel case was obtained by using different turbulence models. The SAS model is capable of resolving largescale turbulent structures without the time and grid-scale resolution restrictions of LES (Large Eddy Simulations), often allowing the use of existing grids created for URANS simulations. For this reason, two different turbulence models, namely URANS (Unsteady Reynolds Averaged Navier Stokes) model, SAS (Scale Adaptive Simulations) model have been applied. Acoustic sources were computed based on the pressure fluctuations and sound pressure level and frequency dependent graphics were plotted with Fast Fourier Transform. On the other hand, acoustic measurements were performed in a semi-anechoic chamber for both of them. When the experimental and numerical results were compared with the previously determined receiver points, the accuracy rate was obtained as SAS, URANS respectively.

The success of supersonic air-breathing propulsion systems will be largely dependent on efficient injection, mixing, and combustion inside the supersonic combustion chamber. Fuel/air mixing enhancement inside the combustion chamber will depend on the strategies used to control the fuel jet penetration and liquid fuel droplet size, trajectory, and dispersion. We present in these paper experimental results on the mixing of pure liquid jet, aerated liquid jet and pulsed aerated liquid jet in supersonic cross flow. Transverse aerated liquid jet injection will offer relatively rapid near-field mixing, good fuel penetration and better atomization of liquid fuel. Fully modulated or pulsed fuel jet injection will introduce additional supplementary turbulent mixing. High speed imaging system is used in this study for the visualization of the injection of liquid jet in high speed cross flow. The results presented in this paper show the effect of jet/cross flow momentum ratio, the gas/liquid mass ratio and pulsing frequency on the penetration of aerated liquid jet in supersonic cross-flow. The data generated in this study will be used for the development of active control strategies to optimize the liquid fuel jet penetration and supersonic fuel/air mixing.