Daniel, T. L. & Combes, S. A. 2002 Flexible Wings and Fins: Bending by Inertial or Fluid-Dynamic Forces? Integr. Comp. Biol. 42, 1044–1049. (doi:10.1093/icb/42.5.1044)
Words & phrases I didn't know/was unsure of
- the crux of
- pervasive issue
- a wide swath of scale arguments
- an amalgam of shape and kinematics
- we adopt a two-pronged approach
- we imbue a simple rectangular wing
One of the first papers by Combes stating inertial force dominates the wing deformation in flapping flight, compared to aerodynamic force. The scaling calculation looks elegant but may not be accurate enough for some situations... where rho = rho(l) and A = A(l). The exact distribution should be variable between species but usually both mass and area would be concentrated close to the wing root, which decrease the impact of inertial contribution. In addition, the assumption of "uniformly distributed pressure load" (= aerodynamic force) on the wings is also too simple. I am not quite sure why they didn't use (2/3)L or (3/4)L instead of (1/2)L.
So my impression is that they overestimated the ratio of inertial/aerodynamic due to oversimplification, but the extent is not quite clear yet. It is possible I will calculate this and mention it in my next paper. But before going further I better read her other papers first.