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

Planetary Exploration Using Biomimetics
An Entomopter for Flight on Mars
Table 3-5: Simulation Conditions (Continued)
Free Stream Temperature
Solver
210 K
Segregated-Implicit, Steady
In the CFD analysis, the values of lift and drag coefficients were to be determined. The lift coefficient
and the drag coefficient are given by Equations 3-29 and 3-30, respectively.
2
c = L/(0.5 V S)
Equation 3-29
l
ρ ∞
c = D V S
d
2
/(0.5 ρ ∞
)
Equation 3-30
L and D are the lift and drag forces, respectively, p is the density of the fluid, V is the free stream
velocity, and S is the wing planform area.
All the cases were run for turbulent conditions with the Spalart-Allmaras model and the conditions
shown in Table 3-5. After the solutions converged, the C L and c d values were noted.
According to the “lifting-line theory,” C L - = 2πα, where α is the angle of attack in radians. The
theoretical values of C L obtained from the lifting line theory, and those obtained from the CFD
simulations were compared. Figure 3-40 shows the comparison.
Figure 3-41: Lift Coefficient vs. Angle of Attack
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Phase II Final Report