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 test bed for the development and application of novel closed-loop control recipes.
Computational Fluid Dynamics
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. 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.
Aerospace propulsion is largely of two kinds: Aero propulsion and space propulsion systems. Aero propulsion is mainly for aircraft vehicles such as manned aerial vehicle and unmanned aerial vehicle (UAV). Space includes rocket propulsion such as space launch vehicles and missiles for military, and electric propulsion like ion thruster for the vector control of satellites. Latest, their R&D activities are mainly focused on four requirements: 1) Capability: High Performance/Operability/Durability, 2) Affordability: Low Cost, 3) Safety: Reliability/Robustness, 4) Environmental Compatibility: Low NOx and low fuel consumption. Researchers at Khalifa University are introducing both aircraft propulsion systems such as turbojet and turbofan engines, and rocket propulsion systems like liquid rocket, solid rocket, and hybrid rocket engines.
Combustion is a dominant power source around the globe, e.g. the United Arab Emirates generates 99% of its energy through combustion of hydrocarbon fuels. Enhancing the Emirate’s energy security to meet future demand via optimizing the Emirate’s oil and gas resources is one the principles of the Abu Dhabi Economic Vision 2030. There is a need to both improve the energy efficiency of our engines and reduce pollution from fuels. Such improvements critically depend on our ability to understand, predict, and accurately model detailed combustion events. In KU, we are focusing on obtaining a deeper understanding of the chemical dynamics inside engines. We believe that better predictions of reactive flows will help to increase the efficient use of fuels, reduce polluting byproducts, and assist in the development of alternative fuel sources. We are also focusing on the development of an accurate and rational algorithm to reduce the computational cost of simulating combustion processes.