Phase II Final Report - NASA's Institute for Advanced Concepts

Chapter 3.0 Vehicle Design
3.3 Wing Aerodynamics
Figure 3-124: CFD Results of the Unblown Case
3.3.3.10 Design of Experiments and Parametric Analysis
After having evaluated the results of baseline case, and validating the analytical model with the
values obtained by CFD analysis, the next step was to explore the design space parametrically.
As explained earlier, there are five control variables: span, forward velocity, flapping frequency,
flapping amplitude, and pitching amplitude. The sensitivity of key responses lift, thrust,
moment, and power coefficients with the variability of control variables was assessed parametrically.
A complete parametric exploration of the design space would require selection of adequate
ranges for these control variables and then the sensitivity of each response variable must be
determined in the five dimensional space. The existence of a feasible design space must also be
calculated based on constraints being imposed by other disciplines such as structural integrity,
the flapping frequency, etc. Similarly, forward speed will have a limitation based on the exploration
requirements, and the shape parameters may also be confined as per the communication and
avionics payload. Keeping all these aspects in mind, the following ranges were selected to make
an initial estimation of the design space:
a. Span: 2.6ft to 4ft
b. Forward velocity: 14ft/sec to 26 ft/sec
c. Flapping frequency: 6Hz to 16Hz
d. Flapping amplitude: 45degrees to 75 degrees
e. Pitching amplitude: 8 degrees to 12 degrees
Based on the ranges of these variables defined above, the five dimensional design space has
been defined. The key responses at different points within the design space must then be evalu-
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