A reduced-order hydroelastic analysis of 2D hydrofoil considering supercavitation effects

ABSTRACT

An efficient two-dimensional reduced-order hydroelastic model for studying supercavitation phenomenonwith zero cavitation number is proposed. In order to compute fluid eigenmodes, unsteady hydrodynamic model is derived using the finite-element method along with the potential flow assumption. This model takes advantage of a new real time, direct algorithm to compute the pressure distribution around the hydrofoil, which avoids any iterative scheme to find cavity extent as like as conventional method. The present approach starts by specifying the steady cavitation domain for the zero cavitation number, then, it is assumed that unsteady cavitation flow around the steady-state leads to small fluctuation of the flow velocity around the steady boundaries. According to the present non-iterative scheme, the unsteady hydrodynamic lift and moment are attained and utilised with the structural model, obtained by Lagrange equations of motion, to construct governing reduced-order hydroelastic model. Using such an approach, the hydroelastic behaviour of a model with two degrees of freedom in pitch and plunge direction is investigated and the instability margin of the foil is assessed.

KEYWORDS:

• Hydroelastic model
• cavitation
• finite-element method
• reduced-order modelling
• two degrees of freedom model

Disclosure statement

No potential conflict of interest was reported by the authors.