A flying aircraft disturbs the local atmosphere through which it flies creating a turbulent vortex at each wing tip known as a wake vortex. These vortices can persist for several minutes and endanger other aircraft traversing that turbulent airspace; large vortices are essentially invisible horizontal tornadoes and are a grave threat to smaller aircraft, especially during landing and take off. ...

An experimental study has been conducted to investigate the flow characteristics over two rounded contour bumps. Vane-type vortex generators or longitudinal aligned passive by-pass jets were implemented in attempt to achieve wake flow control in rounded contour bumps. According to the results collected from the surface oil flow visualisation experiments, it was observed that the use of both the...

In order to study the turbulent structure of wake flow around the rear view side mirror of a passenger car, moment property and energy spectra in the mirror wake and fluctuating pressure distribution on the mirror surface have been measured by several experimental tools in an open circuit wind tunnel at the Reynolds number of 2 × 105. It was found that time-averaged streamwise velocity very nea...

The slender body theory, lifting surface theories, and more recently panel methods and Navier-Stokes solvers have been used to study the hydrodynamics of fish swimming. This paper presents progress on swimming hydrodynamics using a boundary integral equation method (or boundary element method) based on potential flow model. The unsteady three-dimensional BEM code 3DynaFS that we developed and u...

Although wake vortices are known to decay more rapidly near the ground than away from the ground, the details of the ground interaction are not well understood. Propeller anemometer arrays located under the approach path have been used to study vortex transport and provide some information about the vortex interaction with the ground, such as the generation of secondary vortices via boundary-la...

Swimming and flying animals generate unsteady locomotive forces by delivering net momentum into the fluid wake. Hence, swimming and flying forces can be quantified by measuring the momentum of animal wakes. A recently developed model provides an approach to empirically deduce swimming and flying forces based on the measurement of velocity and vortex added-mass in the animal wake. The model is c...

Compared with common airliners, High/Medium Altitude Long Endurance (HALE/MALE) RPAS are lighter and have larger wingspan. Therefore RPAS will be extremely sensitive to vortex interactions with larger airliners, not only during departures and arrivals, but also at medium and high altitudes during the en-route phase. The extent of this sensitivity shall be investigated in order to determine safe...

Turbulence studies were made in the wake of a rotating circular cylinder in a uniform free stream. The interest was to examine the turbulence properties at the suppression of periodicity in vortex formation process. An experimental study of the turbulent near wake of a rotating circular cylinder was made at a Reynolds number of 9000 for velocity ratios, λ between 0 and 2.7. Hot-wire anemometry ...

An algorithm for the detection and estimation of a wake vortex using a lateral Range Height Indicator (RHI) observation of a pulsedDoppler lidar is proposed. By estimating physical parameters from measured Doppler spectra, the proposed method achieves high accuracy and robustness even in low Carrierto-Noise Ratio (CNR) conditions. This paper describes the methodology and presents an initial eva...

This research describes the unsteady two-dimensional reacting flows around a circular cylinder. The numerical solution combines the random vortex method for incompressible two-dimensional viscous fluid flow with a Simple Line Interface Calculation (SLIC) algorithm for the propagation of flame interface. To simplify the governing equations, two fundamental assumptions namely Low Mach Number and ...