Comments on: Solar-Powered UAV Under Development http://www.alternative-energy-news.info/solar-powered-uav-under-development/ Alternative Energy News and Information about Renewable Energy Technologies: Articles, Discussions, News and Videos. Mon, 25 Apr 2011 00:53:00 +0000 http://wordpress.org/?v=2.9 hourly 1 By: James P. Turpin http://www.alternative-energy-news.info/solar-powered-uav-under-development/#comment-9419 James P. Turpin Wed, 20 Jan 2010 16:11:14 +0000 http://www.alternative-energy-news.info/?p=775#comment-9419 I'm sure that the researchers are aware that their model isn't optimal size. They are still seeking the modest funding around the level of one-year salary. I’m sure that the researchers are aware that their model isn’t optimal size. They are still seeking the modest funding around the level of one-year salary.

]]> By: Jack http://www.alternative-energy-news.info/solar-powered-uav-under-development/#comment-9418 Jack Wed, 20 Jan 2010 14:48:25 +0000 http://www.alternative-energy-news.info/?p=775#comment-9418 I flew radio controlled sailplanes and electric powered models of the same size as the Green Falcon for more than 20 years. The wingloading proposed (approx 1.25lb/sf) will result in a very fast and difficult to fly model. At a higher wingloadings with payload and computer controlled guidance / autopilot on board and flown at high altitlude necessary for the mission profile described the Green Falcon will be even faster. From experience I can tell you that bigger is better from an aerodynamic point of view at the Reynolds Numbers that the aircraft described will produce at high speed. I predict that you will learn that a larger wingspan (say 4m) will perform far better aerodynamically, require less power to remain aloft because of lower drag, be less susceptible to upset due to turbulence, carry a far greater payload with less degradation of flight performance and be more robust. You should also consider the fact that miniature aircraft at high altitude are a serious collision hazard to manned aircraft as they are virtually invisible to a pilot. The Green Falcon will need to be HIGHLY visible from the cockpit of a manned aircraft and should be able to cruise at altitudes ABOVE commercial air traffic (> 40,000 ft) in order not to pose a collision hazard. Good luck Jack I flew radio controlled sailplanes and electric powered models of the same size as the Green Falcon for more than 20 years. The wingloading proposed (approx 1.25lb/sf) will result in a very fast and difficult to fly model. At a higher wingloadings with payload and computer controlled guidance / autopilot on board and flown at high altitlude necessary for the mission profile described the Green Falcon will be even faster.

From experience I can tell you that bigger is better from an aerodynamic point of view at the Reynolds Numbers that the aircraft described will produce at high speed. I predict that you will learn that a larger wingspan (say 4m) will perform far better aerodynamically, require less power to remain aloft because of lower drag, be less susceptible to upset due to turbulence, carry a far greater payload with less degradation of flight performance and be more robust.

You should also consider the fact that miniature aircraft at high altitude are a serious collision hazard to manned aircraft as they are virtually invisible to a pilot. The Green Falcon will need to be HIGHLY visible from the cockpit of a manned aircraft and should be able to cruise at altitudes ABOVE commercial air traffic (> 40,000 ft) in order not to pose a collision hazard.

Good luck

Jack

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