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A numerical study on sunroof noise reduction is carried out. One of the strategies to suppress the noise is to break down the strong vortices impinging upon the trailing edge of the sunroof into smaller eddies. In the current study, a serrated sunroof trailing edge with sinusoidal profiles of wavelengths is investigated for the buffeting noise reduction. A number of combinations of wavelengths and amplitudes of sinusoidal profiles is employed to examine the effects of trailing edge serrations on the noise reduction. A generic vehicle model is used in the study and a straight trailing edge is considered as a baseline. The results indicate that the trailing edge serration has a significant impact on the sound pressure level (SPL) in the vehicle cabin and it can reduce the SPL by up to 10~15 dB for the buffeting frequency.

A numerical study of transient, compressible, reacting flow inside an adiabatic catalytic converter is carried out with the one–dimensional model. The important physical/chemical phenomena existing in the catalyzed monolith are included in the model. The effects of the time dependent inlet mass flow rate and some important geometrical parameters on the gas/solid phase temperatures along the converter and the conversion efficiency are investigated. Results show that the monolith (wall) temperature along the converter, the maximum monolith temperature, the location of the reaction front, and the conversion efficiency are affected by time dependent fluctuations of the inlet mass flow rate. In addition, the converter characteristics and the conversion efficiency are very sensitive to the geometrical parameters (such as the cell density, the void fraction, and the wall thickness).