Hydrophysics

Hydrophysics

Experimental Study of a Seaplane Hull Model in Porpoising Mode

Document Type : Original Article

Authors
Mohammad Norouzian 1
Bahadoor Saranjam 2
1 Faculty of Naval Aviation, Malek Ashtar University of Technology
2 Faculty of Naval Aviation.Malek Ashtar University of technology
Abstract
The occurrence of longitudinal oscillations during hydrodynamic tests of seaplane models in towing tanks has motivated this research. This study experimentally investigates porpoising behavior in the hull model of a seaplane. Due to the inherent risks of porpoising, initial efforts ensured that the phenomenon was both observable and repeatable throughout various test stages. The effects of modifying operational parameters—including shifting the center of gravity, increasing speed within the porpoising regime, reducing weight, applying an initial longitudinal moment, as well as the presence, absence, and displacement of skis—were systematically examined. Weight and center of gravity reductions correspond to fuel consumption or payload unloading in practical operation. All tests were repeated to verify result accuracy. Findings indicate that adjusting certain parameters can extend the stability range of the hull by increasing the speed at which porpoising initiates.
Keywords
Porpoising
Planing Hull
Hydrodynamic Stability
Sliding Fuselage
towing tank

Subjects

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  • Receive Date 11 March 2025
  • Revise Date 01 June 2025
  • Accept Date 11 June 2025