due 11/1/2017 before midnight via Learning Suite -50 possible points
+due 10/23/2024 before midnight via Learning Suite +25 possible points
-Predict some key performance metrics for your aircraft including:
+Consider a relatively large RC aircraft with the following components.
Discuss your results and what you think is the best metric for your application. Based on your decision report your design speed and design CL.
- -Spend at least four hours this week working on building (and ideally some RC flying though it’s not required that you make it to the flying stage). Note: that is four hours each, not four hours collectively as a team.
- -Report:
- -At a flight speed of \(V_\infty = 15\) m/s, plot the efficiency of the propeller, motor, battery, as well as total efficiency (four curves) as a function of propeller rotation speed from 400 rad/s to 600 rad/s.
+Hints: It’ll be easiest to work the power chain backwards from propeller, to motor, to battery. Using \(V_\infty\) and \(\Omega\) as inputs you have everything you need to compute all propeller properties by interpolating the propeller data. Some advance ratios may be outside the range of the provided data, and in those cases you can just use the values at the end point. You now know the torque (and rotation speed) on the motor and will be able to compute all the motor quantities. Finally, you now know the power coming into the motor, which must be the power supplied by the battery (note that voltage of battery and voltage of motor are in general not equal), and so can compute all corresponding battery quantities.