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Assumptions and learnings from previous BA

The ideal parameters for pitch angle (θ), heave height (h0), their frequencies (f), and their phase shift (ϕ) are:

Pitch angle amplitude: θ0 = 15-25 degrees
Heave amplitude: h0 = 0,1 m (so total movement 0,2m up and down → atm, more would be better..., goal is 0,115m)
chord length: 0,15 m
heave amplitude / chord length ratio: h* = 0,75-1 (this is the goal, atm we’re at 0.5)
Frequency: f = 0,5 Hz minimum
f = 0,0875 Hz for U = 0,1 m/s and St = 0,35
f = 0,875 Hz for U = 1 m/s and St = 0,35
target frequency should be arround 1 Hz to be able to get some speed (max speed ~ 1,15 m/s)
Strouhal number: St = 03-04 (comes from observation of fish and whales)
Phase shift: ϕ = 75-100 degrees (pitch leading heave)
These parameters ensure high thrust production and high efficiency for thrust-producing harmonically oscillating foils.

Used foil types:

Symmetric: NACA0012
Asymmetric: NACA6412

Optimal Parameters from BA:

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Formulas:

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→
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optimum is 0,8 Hz if we want St = 0,35


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