Vortex dynamics in the wake of a finite span wing in stable stratification.
ORAL
Abstract
A numerical investigation is carried out to study the evolution of wing-tip vortices in a stably stratified environment. Earlier studies have mostly
modeled the wake behind a wing using a pair of counter rotating vortices(Spalart 1996, Ortiz et al. 2015). In the present work we simulate the full
wake behind a finite span wing upto a downstream distance of 60 chord lengths for various levels of stratification. In the unstratified case, nearwake
consists of the vortex rollup and far wake consists of fully developed wing-tip vortices (Navrose et al. 2019). The calculations are carried out at Re
(Reynolds number)=1000 and 1< Fr(Froude number) <10. The results show that as strength of stratification increases, the rollup process of wing-
tip vortex formation is inhibited. The stratification suppresses the vertical motion and baroclinic vorticity of opposite sense as that of wing-tip vortices
is generated that persists along with vortex sheet. At relatively large stratification elongated flat 'V'-shaped structures are observed in the near
wake. The far wake in this case comprises of a mixture of pancake like strutures (Pal et al. 2017) and streamwise elongated vortical structures. The
vortical structures appears to have a well defined wavelength in the streamwise direction.
modeled the wake behind a wing using a pair of counter rotating vortices(Spalart 1996, Ortiz et al. 2015). In the present work we simulate the full
wake behind a finite span wing upto a downstream distance of 60 chord lengths for various levels of stratification. In the unstratified case, nearwake
consists of the vortex rollup and far wake consists of fully developed wing-tip vortices (Navrose et al. 2019). The calculations are carried out at Re
(Reynolds number)=1000 and 1< Fr(Froude number) <10. The results show that as strength of stratification increases, the rollup process of wing-
tip vortex formation is inhibited. The stratification suppresses the vertical motion and baroclinic vorticity of opposite sense as that of wing-tip vortices
is generated that persists along with vortex sheet. At relatively large stratification elongated flat 'V'-shaped structures are observed in the near
wake. The far wake in this case comprises of a mixture of pancake like strutures (Pal et al. 2017) and streamwise elongated vortical structures. The
vortical structures appears to have a well defined wavelength in the streamwise direction.
*The authors acknowledges use of the HPC and PARAM Sanganak facilities set up under the aegis of the Department of Science and Technology (DST) and National Supercomputing Mission, Government of India at the Indian Institute of Technology, Kanpur.
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Presenters
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Mohd. Suhail Naim
- Indian Institute Of Technology Kanpur