NICOP - Versatile Adaptive Micro Turbofan Engine Development for UAS applications
Abstract
Various threats to peace throughout the world, combined with tighter defense budgets, demand newand innovative solutions towards th""e development of future unmanned air vehicles (UAVs). Consideringthe tempo of the engagement, a low cost UAV technology concept is"" needed to provide long range,transonic, reconnaissance capability in remote/contested regions where forward basing is difficult or""prohibited. To date, the vast majority of UAV platforms are intended towards low speed applications.Therefore, the thrust is typic""ally generated by an internal combustion engine, which drives a propeller. Thetypical thermodynamic cycle efficiency of these small"" scale Gasoline Direct Injection or Diesel engines are~ 35%. However, this propulsion scheme that utilizes a reciprocating engine i""s unsuitable for high speedflight, suffers from vibrations that disturb the imaging equipment, and emits a distinct IR and acoustic""signature. Durable, highly efficient, lightweight turbofan engine is proposed to replace the current internalcombustion engines. R""eaching thermodynamic efficiency of ~35% with exhaust gas recuperation, microgas-turbines allow broad range of flight velocities, m""inimize vibrations, and the composite-based nacelle,which ducts the fan, abates the acoustic, radar and thermal signature. As the o""perational envelope ofunmanned and remotely piloted air vehicles expands into the high sub-sonic and transonic speed range, theeng""ine design process requires compromises in thrust, weight, fuel consumption, size, reliability, andmanufacturing cost. Moreover, th""e engine requirements for multiple operating points, consisting of loiteringduring reconnaissance, and high speed flight during cru""ise are conflicting design criteria for an efficientpropulsion system. In general, micro-turbojet engines may offer a simple design"" capable of providing highlevels of thrust, but are marked by poor fuel consumption, hindering range. In contrast, larger platforms""utilize turbofan engine architectures due to their greater propulsive efficiency.To address the issue, in the scope of The Marine"" Corps Warfighting Lab Focus Area 7a, theproposed project involves a single shaft micro turbojet to micro turbofan conversion via i"ntroduction of afan coupled with a continuously variable transmission and a variable bypass nozzle. The micro gas turbinemarket su"ffers from restrained design costs, and therefore in order to shorten the design process to aminimum, the aspiration is to entail a""s few changes as possible to the core design. The solution significantlyimproves maximum thrust, reduces fuel consumption by mainta""ining the core independently running at itsoptimum, and enables a wider operational range, all the meanwhile preserving a simple si""ngle spoolconfiguration. Moreover, the introduction of a variable fan coupling would allow real-time optimization forseveral opera""tional modes. Small gear ratio would yield a lower fan bypass ratio, and therefore performanceresembling a turbojet suitable for hi""gh speed flight, whereas large gear ratio would alter the engine cycletowards a modern turbofan, which provides improved fuel consu""mption during loitering. The goal of theproposed project is to develop a variable cycle micro turbofan, which will allow real-time"" changes of UAVengine operation mode, to better serve the needs of the mission.The project will be conducted in collaboration with"" Izmir Katip Celebi University in Turkey. In thescope of the project, the technology readiness level will be increased from 1 (Basi"c principles observed andreported) to 4 (Component/subsystem validation in laboratory environment).
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Nov 03, 2017
- Source ID
- N629091712176
Entities
People
- Beni Cukurel
Organizations
- Office of Naval Research
- United States Navy