To complete this series of Computational Fluid Dynamics (CFD) on simple rotating paper wings, we now turn our attention to the walkalong tumblewing.

CFD Simulation of a Walkalong TumblewingVelocity vectors at 0 degrees

A tumblewing can be made to fly nearly continuously by pushing a large sheet towards it. Maneuvering the sheet indirectly controls the path of tumblewing. For the CFD simulations I added a large face to the two extreme conditions (i.e., 0 and 90 degrees) of the tumblewing. Then I compared the results with the previous CFD simulations for the rotating paper sheet and tumblewing alone.

Results

Assuming that the trends of lift and drag variation would be similar to the previous results for the standalone wings, I only performed two simulations at 0 and 90 degrees.

Velocity Vectors for Walkalong Tumblewing at 0 Degrees

Velocity Vectors for Walkalong Tumblewing at 90 Degrees

Pressure Iso-Surfaces for Walkalong Tumblewing at 0 Degrees

Pressure Iso-Surfaces for Walkalong Tumblewing at 90 Degrees

Lift for a Walkalong TumblewingCompared to a rotating paper sheet and tumblewing alone

Drag for a Walkalong TumblewingCompared to a rotating paper sheet and tumblewing alone

Conclusions

If we assume the lift and drag trends are similar to the standalone wings then we can see a significant reduction in lift for the walkalong tumblewing. Therefore, for the walkalong tumblewing to work well it requires lightweight (e.g., phone directory page) paper. Also, notice a marked reduction in drag for the walkalong tumblewing, which means it will travel further all things being equal.

Notes

• Build your own tumblewing and learn how to walkalong with instructions from Science Toy Maker.
• The CFD simulation was performed in Caedium Professional using the MRF option for the incompressible, steady-state RANS solver, and the k-omega SST turbulence model.