Gunwale bobbing

We investigate gunwale bobbing, a phenomenon in which a person jumping on the gunwales of a canoe achieves horizontal propulsion by forcing it with vertical oscillations. The canoe moves forward by surfing the resulting wave field. After an initial transient, the canoe achieves a cruising velocity w...

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Bibliographic Details
Main Authors: Benham, GP, Devauchelle, O, Morris, S, Neufeld, J
Format: Journal article
Language:English
Published: American Physical Society 2022
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author Benham, GP
Devauchelle, O
Morris, S
Neufeld, J
author_facet Benham, GP
Devauchelle, O
Morris, S
Neufeld, J
author_sort Benham, GP
collection OXFORD
description We investigate gunwale bobbing, a phenomenon in which a person jumping on the gunwales of a canoe achieves horizontal propulsion by forcing it with vertical oscillations. The canoe moves forward by surfing the resulting wave field. After an initial transient, the canoe achieves a cruising velocity which satisfies a balance between the thrust generated from pushing downwards into the surface gradients of the wave field and the resistance due to a combination of profile drag and wave drag. By superposing the linear wave theories of Havelock [Proc. R. Soc. A 95, 354 (1919)] for steady cruising and Helmholtz for an oscillating source, we demonstrate that such a balance can be sustained. We calculate the optimal parameter values to achieve maximum canoe velocity. We compare our theoretical result to accelerometer data taken from an enthusiastic gunwale bobber and to estimates from videos of other canoeing aficionados. Finally, we discuss the similarities and differences with other examples of macroscopic wave-driven bodies and comment on possible applications to competitive sports.
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spelling oxford-uuid:ca7fc52c-d06c-46f0-940c-c963016c39a92022-08-15T09:42:13ZGunwale bobbingJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:ca7fc52c-d06c-46f0-940c-c963016c39a9EnglishSymplectic ElementsAmerican Physical Society2022Benham, GPDevauchelle, OMorris, SNeufeld, JWe investigate gunwale bobbing, a phenomenon in which a person jumping on the gunwales of a canoe achieves horizontal propulsion by forcing it with vertical oscillations. The canoe moves forward by surfing the resulting wave field. After an initial transient, the canoe achieves a cruising velocity which satisfies a balance between the thrust generated from pushing downwards into the surface gradients of the wave field and the resistance due to a combination of profile drag and wave drag. By superposing the linear wave theories of Havelock [Proc. R. Soc. A 95, 354 (1919)] for steady cruising and Helmholtz for an oscillating source, we demonstrate that such a balance can be sustained. We calculate the optimal parameter values to achieve maximum canoe velocity. We compare our theoretical result to accelerometer data taken from an enthusiastic gunwale bobber and to estimates from videos of other canoeing aficionados. Finally, we discuss the similarities and differences with other examples of macroscopic wave-driven bodies and comment on possible applications to competitive sports.
spellingShingle Benham, GP
Devauchelle, O
Morris, S
Neufeld, J
Gunwale bobbing
title Gunwale bobbing
title_full Gunwale bobbing
title_fullStr Gunwale bobbing
title_full_unstemmed Gunwale bobbing
title_short Gunwale bobbing
title_sort gunwale bobbing
work_keys_str_mv AT benhamgp gunwalebobbing
AT devauchelleo gunwalebobbing
AT morriss gunwalebobbing
AT neufeldj gunwalebobbing