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Comprehensive System Identification of Ducted Fan UAVs - Cal Poly

Comprehensive System Identification of Ducted Fan UAVs - Cal Poly

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the duct, the effects <strong>of</strong> the man need to be removed from the above moments. This isdone by approximating the man as a flat plate (6’ x 2’). While crude, this investigation ismerely to establish a trend with the pitching moment characteristics <strong>of</strong> ducted fanvehicles.The relationship for the drag on a flat plate for Re > 1000 is presented as Figure 3.16.Figure 3.16 – Drag over a Flat Plate Perpendicular to FlowWith the approximation in size <strong>of</strong> the man, a drag coefficient <strong>of</strong> C D = 1.1 is foundfrom Figure 3.15. It follows that the drag <strong>of</strong> the man will vary with velocity as inEquation 3.19.D1 v2ρ AC2plate=D (Equation 3.19)- 49 -

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