.
VAATE work will be concentrated into three focus areas and two pervasive areas. Focus areas will include durability; work on a versatile core, and intelligent engine technologies. Pervasive areas, which are really incubators for hatching ideas that should be included in the VAATE focus areas, will be segregated into the categories of high-impact technologies and UA.
Propulsion – Internal Combustion
Reciprocating internal combustion gasoline engines are widely used in fixed wing UA with take-off gross weights less than 2,000 pounds. This is true among legacy UA, (Pioneer, Shadow 200, and Predator) and numerous demonstration aircraft from both industry and government laboratories where two and four cycle engines are used. While either cycle offers advantages and disadvantages, the demonstrated lower cost and better efficiency of these engines precludes developing turbo-shaft engines to meet the engine needs for UA in these size classes. However, these engines do not meet the requirements for a common battlefield fuel as defined in DoD 4000. In addition, the engines tend to fall short in reliability/durability as compared to man-rated aircraft engines, making them less attractive to warfighters who rely heavily on the data received from their UA payloads to make real-time decisions. Future small UA will continue to utilize these low cost, gasoline engines unless significant advances are made. Two potential areas are weight reduction for true diesel cycle engines and successful modification of existing gasoline engines to burn jet propellant (JP) fuels with increased reliability.
True diesel cycle engines had been precluded up to this time due to significantly higher engine weight as compared to most gasoline engines. However, the advent of turbo-diesel technologies over the last few decades, along with continuing development work with engine manufacturers to reduce the weight of diesel engines has advanced the possibility of diesel engines being used by light aircraft. For example, the Thielert Group in Germany has worked for many years to qualify several of their engines with the European Aviation Safety Agency (EASA), for use in general aviation aircraft. Their efforts have recently proven fruitful with certifications to operate their Centurion 1.7 engine on Cessna 172 aircraft, and soon this same engine will be certified for the Piper Warrior III. Both the government and industry are already evaluating an application of this type on the MQ-1 Predator to determine what “actual” performance results would be realized when installed.
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址：无人机系统路线图 Unmanned Aircraft Systems Roadmap(132)
