Dynamically scaled aircraft

NLR is currently developing a self-powered free-flying dynamically scaled model of its laboratory aircraft (Cessna Citation II). Dynamically scaled models are regularly used for validation of the design, which is a paper or Computer Aided exercise, analysed by numerical methods. Commonly known are the (static) windtunnel tests; these reduce cost and risk of full-scale tests by providing an appropriate model of the aircraft.

Self-powered, free-flying dynamically scaled models though can be used to discover the dynamic “realm”. You can think of control, stability, upset condition (like spin recovery, high angle of attack, stall). This is not possible with static test, and in most cases very risky when using a full-scale prototype.

The challenge of a free-flying scale model is the (dynamic) scaling; some parameters do not scale easily (think about Reynolds / Froude / Mach scaling techniques). NLR is seeking for the best match between full-scale flight testing (with a reference aircraft, the NLR Citation II in this case) and its dynamically scaled model, which is currently being developed.

So what we have for you is:

• a research programme called “Scale Model Aircraft Research & Development” (SMARD)
• the development (within SMARD) of a dynamically scaled model of the NLR Citation II research aircraft
• a platform that has about four (4) metres wingspan and a projected maximum take-off weight of 120kg
• systems engineering capability to be used for complex SMARD platforms
• integration means for additional payload to a SMARD platform
• a technology demonstrator for many RPAS/UAS/drone applications
• operational environment to perform flight testing of a SMARD platform
• many opportunities to cooperate with external partners on dynamically scaled aircraft research and development