WorldCat Identities

Mustafa, Mansoor

Works: 3 works in 3 publications in 1 language and 3 library holdings
Genres: Academic theses 
Roles: Author
Publication Timeline
Most widely held works by Mansoor Mustafa
A handbook of behavioural sciences for medical & dental students by Mowadat H Rana( Book )

1 edition published in 2012 in English and held by 1 WorldCat member library worldwide

Analyzing the effects of preventive maintenance on a manufacturing cell by Mansoor Mustafa( )

1 edition published in 1990 in English and held by 1 WorldCat member library worldwide

Investigation into offset streams for jet noise reduction by Mansoor Mustafa( )

1 edition published in 2015 in English and held by 1 WorldCat member library worldwide

This effort investigates the near field behavior of two ideally-expanded subsonic dual-stream jets. One case implements a traditional symmetric, concentric dual-stream nozzle configuration while the other imposes an asymmetric, eccentric layout to model the behavior of an offset stream. The essence of an offset stream is to force an uneven azimuthal distribution of the secondary coflow and create an outside stream that varies in thickness. Past studies have shown a benefit in acoustic propagation in the direction of the thickest coflow and the present work further analyzes this phenomenon. A LES (Large Eddy Simulation) approach is implemented to run the simulations for both cases and a number of qualitative and quantitative analyses tools are used for post-processing. A reduction in the noise levels for the lower, thicker side of the eccentric nozzle is observed in comparison to the baseline concentric case. Examination of the mean flow behavior shows a shorter, thinner primary potential core for the offset case and a faster axial velocity decay rate. The asymmetric distribution of the coflow causes varying velocity profiles in the radial direction for the top and bottom regions and consequently produces unique flow features on either side. Lower levels of shear stress and slower decay rates lead to less turbulence production on the lower side of the eccentric nozzle. An investigation into the flow structures reveals lower vorticity and weaker convective structures on the bottom which influences propagation in that direction. Two-point correlation analysis reveals the presence of smaller turbulence scales in the lower, thicker portion of the eccentric case. This is further confirmed by an Empirical Mode Decomposition (EMD) study that shows lower frequency ranges dominate the concentric near field in comparison to the eccentric. The combination of these unique features demonstrate the principles behind the acoustic benefit of implementing offset stream flows in dual-stream nozzle configurations
Audience Level
Audience Level
  General Special  
Audience level: 0.62 (from 0.20 for Analyzing ... to 0.95 for A handbook ...)

Alternative Names
Mansoor Mustafa