Aerodynamics is investigated mainly from the point of view of low and transitional Reynolds numbers (Re ≤ 106) with direct applications to nano-to-small Unmanned Air Vehicles (UAV) and high altitude aircraft. Unsteady and nonlinear aerodynamic phenomena occurring around wings, namely laminar-to-turbulent boundary layer transition, shear layer transition, laminar separation bubble, dynamic stall, wing-tip vortices and wavy wakes are examined in detail. Additional aspects of interest include flapping wing aerodynamics and flow control techniques. A wide variety of experimental facilities and equipment is available to support these activities. They include wind and water tunnels (with different specifications and capabilities), wings instrumented with unsteady pressure and hot film sensors, static and dynamic rigs, and flow measurement and visualization techniques. LES and URANS based computational fluid dynamics (CFD) simulations are also performed in these flow regimes via active collaboration with NRC/IAR and Laval University. Other partners include DRDC-Valcartier.
Directed mainly to aerospace applications, research in the feedback relationship between a flexible structure and a moving fluid is examined under different angles. Specific questions related to low and transitional Reynolds numbers are investigated, namely laminar separation flutter, vortex induced vibrations, morphing (active or passive) during flapping flight. The effect of structural nonlinearities due to large displacement and friction for instance, or related to new materials, are also considered in terms of the system dynamics in general and limit cycle oscillations (LCO) in particular. In addition, system identification techniques are being developed and applied to capture the nature of the nonlinearities. The quantification of uncertainties due to noise excitation or system unknowns, and its interaction with nonlinearities, is also studied leading for example to the concept of a probabilistic flutter margin. A number of experimental and analytical tools are exploited to investigate these topics, such as flutter rigs and numerical simulation models. Active external collaborations exist with NRC/IAR, Carleton University, Laval University and the Australian Department of Defence.
There exist a strong focus towards the study of transitional and turbulent flows, with applications to flat-plate boundary layer, pipe flow, jet flow and wake (subsonic and supersonic) flow. Emphasis is placed on the statistical description of these flows, looking at small-scale and large-scale coherent structures, as well as both the dynamic and scalar (temperature) fields. In addition to evident aerospace applications, the knowledge acquired will have a direct application for improving air/fuel mixing in gas turbines, the control of pollutant emissions into the atmospheric boundary layer and for thermal trace dilution. It can also be applied to mixing in internal combustion engines (Diesel engines). The research is performed experimentally and via direct numerical simulation (DNS), with active external collaborations with NRC/IAR, Laval University, Stanford University, Arizona State University and Queen's University. Experimental facilities include a free-jet, closed and open-loop wind and water tunnels, and flow measurements equipment such as hot-wire anemometry.
For more information please contact Dr. Dominique Poirel.