PRojects
SYNTHETIC JETS
Synthetic jets have been investigated for flow control for more than two decades as they require low power, are very simple mechanically, and are based on zero-net mass flux. These benefits greatly increase the efficiency and reduce the weight of the actuation system, which allows for better implementation in different applications. Synthetic jets have a wide variety of applications but are most utilized for active flow control. In this project, we are exploring new designs for synthetic jets, together with their characterization and application.
CONTROL OF FLOW SEPARATION OVER A WING
Flow separation over a wing section at moderate to high angles of attack is one of the fundamental problems of aerodynamics. The separation leads to lift loss and an increase in drag which reduces the aerodynamic efficiency of an aircraft. In this project, we are investigating the control authority of existing actuators and developing new ones, which may help in mitigating the flow separation.
CONTROL OF REVERSE FLOW
Rotary wing aircraft have many civilian and military applications. A large number of studies have focused on improving the maximum forward speed of these aircraft, which is currently limited to about 250 kt. This is because of the phenomena of reverse flow which occurs near the root of the retreating blade. The three main problems associated with reverse flow are negative lift, pitching moment impulse, and dynamic stall. In this project, we are investigating flow control techniques to mitigate this flow separation problem.
Source: NASA-LaRC
CONTROL OF WINGTIP VORTICES
Wingtip vortices develop at the tips of aircraft wings due to a pressure imbalance in the process of generating lift. They lead to induced drag, which accounts for 30-50% of the total aerodynamic drag of an aircraft at high lift configurations, such as during take-off and landing. These vortices are also a major source of turbulence for smaller trailing aircraft, which has led to several catastrophic accidents. In this project, we are investigating flow control techniques at the wingtip to weaken this vortex which will lead to faster downstream dissipation.
Taylor Couette Flow
Taylor-Coette flow is a cornerstone problem in hydrodynamics stability in which the viscous fluid between two rotating cylinders progressively becomes unstable as the angular velocity of the inner cylinder is gradually increased. It is marked by the formation and breakdown of axisymmetric toroidal vortices. In this project, we are investigating tapered cylindrical geometries which lead to various stages of instability along the axis of the cylinder, for the same angular velocity.