Contact: Dr. Vladimir Parezanovic
Studies of drag reduction and wake control of bluff bodies are of immense importance in terms of reducing terrestrial transport fuel consumption and polluting gas emissions. Most of the real vehicle energy expenses are devoted to overcoming the aerodynamic drag, caused mainly by the massive flow separation at the rear of the body. In addition to a large pressure drag, the separated region is a source of fluctuating aerodynamics forces which affect stability and control of the vehicle. With the ever-increasing capabilities of small and cheap microcontrollers, as well as developments in flow sensing devices and actuators, the challenges of effective and robust flow control are beginning to look less insurmountable. The future KU Wind Tunnel Facility will provide a powerful platform for experimental efforts in understanding the complex physics of 3-D turbulent wakes and testing of different flow control approaches. A large array of flow diagnostic methods will be available to study both time-resolved and 3-D wake dynamics. Furthermore, real-time data acquisition hardware will serve as a testbed for the development and application of novel closed-loop control recipes.
Computational Aerodynamics / Fluid Dynamics
Contact: Dr. Vladimir Parezanovic, Dr. Rashid K. Abu Al-Rub,
The use of computational fluid dynamics (CFD) techniques has revolutionized the process of aerodynamic design. CFD enables engineers to analyze the aerodynamic performance of complex design concepts and optimize parameters for improved performance. CFD results are then validated against wind tunnel measurements. In the1980s, for example, Boeing designed and tested around 80 wings during the development of a new airplane, without the use of CFD. Since the 1990s, the use of CFD has increased more than 60 fold, reducing the previous figure of 80 to just 10. Researchers at KU are working on problems, such flow separation control and hypersonic boundary layer transition using CFD. Under heavy winds, or at a high angle of attack, airflow cannot follow the surface of a wind turbine blade and separates. Flow separation is an unsteady phenomenon that causes alternating aerodynamic forces, which can become destructive. As a result, the turbine has to be stopped. Currently, we are investigating flow control concepts to control flow separation and alleviate load fluctuations. This will increase the efficiency and extend the lifespan of wind turbines.