Fluid Dynamics
Lead Research Organisation:
University of Southampton
Department Name: Faculty of Engineering & the Environment
Abstract
In the field wall-turbulence, there is a general consensus that turbulent skin-friction drag primarily comes from the near-wall "streaks" and "vortices" that appear to dominate the near-wall production of turbulent kinetic energy. However, recent evidence suggests that large-scale turbulent structures in the outer part of the boundary layer become increasingly important with increasing Reynolds numbers. In this collaborative project between University of Southampton and Airbus, we will focus on developing and characterizing synthetic-jet actuators and examining their impact on the outer region of a turbulent boundary layer. Laboratory experiments will be carried out using various state-of-the-art diagnostics to measure the impact of an array of these jets on turbulent boundary layers. It is believed that such devices hold long term potential for drag reduction in aircraft.
Studentship Projects
| Project Reference | Relationship | Related To | Start | End | Student Name |
|---|---|---|---|---|---|
| EP/N509358/1 | 01/10/2015 | 31/03/2021 | |||
| 1803436 | Studentship | EP/N509358/1 | 01/10/2016 | 30/06/2020 | Girish Jankee |
| Description | This grant has so far enabled the development of a new design for the internal geometry of the orifice of a synthetic jet actuator. A methodology has been proposed which describe how to design more effective actuators. Such a breakthrough can lead to more efficient and higher performance-achieving actuators. Additionally, a study has been carried out to improve the accuracy of the measurement technique used in the experiments. For stereoscopic particle image velocimetry (SPIV), the bias error known has pixel locking has been mitigated by performing the cross correlation of frames in the image plane. Such a process has also allowed elimination of Moire fringes. Such high artifacts have been found to contaminate the mean statistics of PIV datasets. Overall, the ability to simultaneously filter out high frequency artifacts in the mean velocities and deal with pixel locking contamination in the root mean square (RMS) velocities advocates for a pervasive application of the image plane cross-correlation technique in SPIV. |
| Exploitation Route | The results can lead to lower energy consumption actuators being developed which can be useful in the aerospace industry (flow separation delay, stall control, drag reduction) as well as in electronic devices where impingement cooling due to synthetic jet actuators is important. Auxiliary repercussions of this study lead to enhanced mixing and heat transfer at a lower operational cost. Pixel locking and Moire fringes correction methodology can be applied a posteriori to contaminated datasets and improve the accuracy of results obtained from PIV processing. |
| Sectors | Aerospace, Defence and Marine,Energy,Manufacturing, including Industrial Biotechology,Transport |