A standard cruise height is 35,000 feet for a commercial jet aircraft, but at that high altitude the air temperature plunges below -51 degrees Celsius and ice can easily form on wings. To prevent the formation of ice and then the aircraft, the current systems use the heat produced by burning fuel. But these high-temperature systems, which rely on fuel, cannot be used on the proposed temperature-sensitive electrical materials in next-generation aircraft.
Because scientists are looking for new anti-freeze methods, physicists from Northwestern Polytechnological University in China and Iowa State University have taken a different approach. They have published evidence, in the magazine Fluids Physics, from AIP Publishing, which shows that equipment that is important in controlling landing and double water abstraction can be like icing control.
"The current anti-exclusion methods are not suitable for next generation flight systems based on the new aviation technologies," Xuanshi Meng says an author on the paper. "We've found a great way to manage the icing on these new aircraft."
It depends on plasma actuators.
Plasma actuators are a special type of short electric circuit. When a high voltage is applied across the two electrons, it causes the particles of air above its ion to form, forming plasma, and stimulating flow, or wind. This plasma flow over the actuator has been handled from the front to control the aerodynamics of aircraft wings, changing the lift and dragging for landing and ascending (known as flow control applications). But plasma actuaries are not only releasing wind that has to stimulate.
"When applying high voltage, most of it is converted into heat and the rest is turned inductive flow or ionic egg over the actuator, so the plasma actuator has effects t aerodynamic and heat, "said Meng.
"By linking the aerodynamic and thermal aspects of the plasma actor, we have provided a completely new approach to icing and efficient flow management."
The plasma management team of Polytechnical University of Northwestern first realized the impact of plasma actuaries on icing in 2012, when an ice cube installed in the plasma pest area poured quickly.
To further demonstrate the mechanism for plasma ice protection, the team has designed plaenma release plasma actuaries that are very thin, with surface leaf and set on air flour NACA 0012; to print on paper. Three configurations of an actuary were set up to investigate how different aerodynamics affected ice formation. Rapid cameras were then used, alongside infrared thermal imaging and particle dispersion lasers, to imagine how the flow caused and the thermal output interacted.
Tests were carried out in still air conditions as well as inside an icing wind tunnel, where cold particles of air were fired on the air foil. The team found that thermal and flow dynamics were inevitably interlinked for each of the three actuaries.
The plasma actuators placed perpendicular to the surface of the air flue were the most effective when transferring heat along the wing, preventing the formation of ice completely. By comparing heat transfer and flow between the different designs, the team came to the conclusion that the best design needed to generate as much heat locally, while mixing it well with the air flow coming in.
"This could be used to design an effective anti-exclusion system at a low enough temperature to prevent strain on the design of aircraft composites and the next generation," said Meng.
Meng student, Afaq Ahmed Abbasi, added, "The conventional anti-exclusion technique uses air as hot as 200 degrees Celsius to evaporate the water droplets, and composite material cannot afford such high temperatures. Plasma icing control prevents the supercool drops from forming ice on the surface of the vehicle without such high temperatures, which is good for the composite materials. "
Meng explained that offering his team to use plasma actuators as anti-emulsifiers is "surprising" to liquid mechanics experts. Meng admits that they are at the beginning of this research and that they need to find out how thermal and flow effects are connected, and how exactly they work with each other to disperse top-surface drops from the surface of a wing.
Materials provided by American Institute of Physics. Note: Content can be edited for style and length.