Mechanical Solutions
I have worked out a schematic
lift and drag measuring set-up. It
does not, however, accommodate rotating blades. Anyone wishing to critique
this with me (I am confident of, but not certain of the method) should get in
touch with me.
* Rotating airfoils tend to exhibit advanced or retarded stall points when compared with static foils. An early experimental determination of the lift and drag coefficients of rotating oarblades was made at MIT in 1993. (see Ramsey, bibliography).
Computer Solutions
The capability exists, through solving the Navier-Stokes flow equations
using finite difference or finite element techniques, to estimate the lift and
drag coefficients of virtually any static and totally immersed three-
dimensional planform at any angle of attack in any fluid at any fluid
velocity. This capability extends to surface effects and partial immersions,
etc. Blade designers could look into capabilities such as those offered by
Fluent, Inc..
Predicting Oarblade Performance
Once good sets of coefficient data have been calculated or measured for
promising blade designs they can be rigorously compared for performance and
efficiency by entering the new data into a computer model where all variables
but the ones of immediate interest can be controlled.