Syamir Alihan Showkat Ali
Thumbnail Image
Preferred name
Syamir Alihan Showkat Ali
Official Name
Syamir Alihan, Showkat Ali
Alternative Name
Alihan Showkat Ali, Syamir
Showkat Ali, Syamir A.
Ali, Syamir Alihan Showkat
Showkat Ali, S.A
Showkat Ali, Syainir Alihan
Main Affiliation
Scopus Author ID
57190746528

Research Output

Filters

3
Reset filters

Settings
Now showing 1 - 3 of 3
  • Publication
    Aeroacoustic performance of high-lift airfoil with serrated slat cusp
    ( 2020-01-01)
    Jawahar H.K.
    ;
    Syamir Alihan Showkat Ali
    ;
    Azarpeyvand M.
    ;
    da Silva C.R.I.
    Experimental measurements to assess the aeroacoustic capabilities of 30P30N airfoil fitted with two different types of serrated slat cusps were carried out at the aeroacoustic wind tunnel at the University of Bristol. The results from the simultaneous surface pressure measurement within and close to the slat cove region and far-field noise measurements above the slat trailing edge are presented to gain a deeper understanding of the noise generation mechanism of the slat and other presented configurations. The far-field noise measurement results showed that significant noise reduction at the vortex shedding frequency can be achieved by the use of serration-2 and No-Cusp configuration. The coherence results for all the frequencies are almost zero for the No-Cusp configuration and the coherence was notably reduced for the Serration-2 configuration. Further higher order statistical and spectral analysis showed that even the serration-1 with small serrations reduces the energy within the norrowband peaks to some level.
  • Publication
    Aerodynamic and aeroacoustic performance of high-lift airfoil fitted with slat cove fillers
    ( 2020-08-04)
    Kamliya Jawahar H.
    ;
    Syamir Alihan Showkat Ali
    ;
    Azarpeyvand M.
    ;
    Ilário da Silva C.R.
    Experimental measurements were carried out to assess the aerodynamic and aeroacoustic performance of an MDA 30P30N airfoil fitted with two different types of slat cove fillers. The aerodynamic results are presented for lift and drag measurements and mean surface pressure measurements, while the aeroacoustic results are presented for the near-field surface pressure fluctuations and far-field noise measurement. The flow measurement results show that there is no significant difference in the aerodynamic lift and drag between the tested cases, however, the slat cove filler configurations exhibit a much better lift-to-drag performance. The pressure coefficient results show that the use of slat cove fillers lead to a slight decrease in the suction peak over the main-element of the airfoil. In order to better understand the flow-field and the noise generation mechanism of the airfoil with slat cove fillers, simultaneous near-field and far-field noise measurements were carried out. The result shows that the use of the slat cove filler can generally lead to a significant reduction of the broadband noise and eliminate the characteristic tonal noise generated by the slat. The directivity pattern and the overall sound pressure level of the radiated noise have shown that a significant noise reduction can be achieved with the applications of the slat cove fillers. The multiple tonal phenomena generated by the slat were also analyzed using the continuous wavelet transform method and higher order spectral analysis methods.
  • Publication
    Turbulent flow interaction with a circular cylinder
    ( 2020-01-01)
    Maryami R.
    ;
    Syamir Alihan Showkat Ali
    ;
    Azarpeyvand M.
    ;
    Afshari A.
    This paper presents a comprehensive experimental study on the unsteady pressure exerted on the surface of a round cylinder in smooth and turbulent flows. A highly instrumented cylinder with several static pressure taps and dynamic pressure transducers at different spanwise and peripheral locations was used, enabling extensive dynamic surface pressure, coherence, and turbulence length-scale analysis. The effects of the free-stream turbulence and turbulent length scale are investigated by placing the turbulent-generating grids within the wind tunnel duct. For both the laminar and turbulent incident flows, the surface pressure results show the emergence of the fundamental, first and second harmonics at most peripheral angles, while at the cylinder base, the surface pressure spectra are dominated by the first harmonic. It has also been observed that an increase in the level of the turbulence intensity results in an increase in the energy level of unsteady pressure acting on the cylinder. An increase in the length scale of the incoming flow structures is shown to result in an increase in the energy level of the tonal frequencies and the broadband content of the surface pressure spectra. The spanwise coherence results have also shown that an increase in the length scale of the flow structures increases the spanwise correlation length of the flow structures at the vortex shedding frequency at the stagnation point, while at the cylinder base, the spanwise correlation length decreases at the vortex shedding frequency.