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Carbon Nanotube Coating for UAV All-Weather

Operations

The phenomenon of ice accretion on aircraft wings and control surfaces is a wellrecognized challenge in aerospace engineering. And while large aircraft are commonly equipped with efficient anti-icing and deicing devices, these are usually unsuitable for small aircraft and essentially useless for unmanned aerial vehicles. For UAVs, which each week are tasked with a wider range of operations, it is vital to be able to detect and accommodate ice adhesion on wings, control surfaces and airspeed sensors since ice accretion modifies the shape of the aircraft and alters its measurements, thus changing resulting aerodynamic forces and reducing maneuvering capability. In short, the UAV needs an “overcoat” to keep it warm and the ice away in all kinds of weather. More precisely, it needs a resistive heat coating For military use, the metrics demanded of a UAV are clear: Find and assess the target, engage to destroy quickly, and then analyze the results. To maximize that ability means the UAV must keep that loop as short in time as possible. The less interference in operating, the quicker the loop. Ice remains one of the largest impediments to that smooth function, whether affecting the UAV enroute or while on orbit, all over the world temperature and moisture can combine to create icing and not just in the coldest climates. The formula for solving this challenge is one that has proven a winner time and time again. Make the solution more efficient, more transportable, more flexible, more reliable, lighter and less expensive. www.SPECOPS-dhp.com

That is where the battlefield in the UAV anti-ice war will be won. A solution using a carbon nanotube coating has demonstrated the ability to minimize the threat of icing is feasible with current technology. With this carbon nanotube coating, it can operate on less power than other options, is lighter than traditional ice protection systems, has no moving parts and can be easily retrofitted to all existing craft. The coating is sprayed onto an aircraft surface, much like paint. This creates a heated area when power is applied. A controller monitors the heater performance and only applies power levels to selected areas per need and as necessary for flight conditions. The ability of unmanned platforms to loiter at higher altitude for longer durations means they can identify a target and engage in a matter of minutes. That is a strong option against any terrorist targets in the world. Anything that increases that operational envelope of the UAV large and small across all environmental conditions is a significant step forward. Weather currently is one of the biggest enemies of UAV success; mastering the anti-ice conundrum will elevate effectiveness immensely. Developed in 2009 by Battelle, this anti-icing technology called HeatCoat has demonstrated its ability to perform inflight anti-icing and de-icing functions on UAVs during wind tunnel testing where the technology was integrated with representative wing and engine inlet test articles and then placed in an aero-icing tunnel developed by an aircraft manufacturer. The chamber was designed to generate the type

of icing conditions a UAV could encounter while in-flight. Temperatures dipped as low as -22 degrees Fahrenheit, with air speeds reaching up to 182 knots. The coating successfully performed anti-icing and de-icing functions. The carbon nanotube coating is integrated into the normal coating stack found on an aircraft. It is directed through the use of an intelligent autonomous closed-loop controller—a system that senses environmental conditions and the condition on the wings and makes decisions regarding power application. Power is applied distinctively for each heater zone. Thus, you do not have to heat up every section of the wing at the same time. That adaptive ability means you can heat one section for 30 seconds, another for an individual short period and so on, a benefit that helps keep the power demand for an electrical thermal system low. Continued work on HeatCoat has focused on maintaining its ability to perform over the lifetime of the system and to ensure its durability. Results have shown that it will last the lifetime of the aircraft and will not degrade over time. Once controller development has been completed the next steps would be in-flight demonstration and certification A resistive heat coating helps UAVs operate in conditions that were difficult for them to operate in before. It has the lowest size, weight and power, it solves a worldwide issue for modern day composite craft, and it is elegantly simple.  Chris Corsbie is director of marketing and communications at Battelle. SPECOPS 14.2 | 17

Special Operations International March 2016  

Special Operations International is the most widely distributed special; operations publication in the world. Coverage includes exclusive in...

Special Operations International March 2016  

Special Operations International is the most widely distributed special; operations publication in the world. Coverage includes exclusive in...

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