Shape optimization of a blended-wing-body underwater glider using surrogate-based global optimization method...

Area of Science:

• Fluid Dynamics
• Naval Architecture
• Computational Engineering

Background:

• Conventional cylindrical autonomous underwater gliders (AUGs) have limitations in hydrodynamic performance.
• Blended-wing-body underwater gliders (BWBUGs) offer superior hydrodynamic efficiency but pose complex shape optimization challenges.
• Existing optimization methods for BWBUGs are computationally intensive and time-consuming.

Purpose of the Study:

• To propose a novel surrogate-based shape optimization (SBSO) framework for BWBUGs.
• To enhance the optimization efficiency and quality for BWBUG shape design.
• To improve the hydrodynamic performance of BWBUGs.

Main Methods:

• Constructing a parametric geometric model of the BWBUG based on seven sectional airfoils.
• Employing an improved ensemble of surrogates based global optimization with hierarchical design space reduction (IESGO-HSR).
• Optimizing selected sectional airfoils to achieve the optimal BWBUG shape.

Main Results:

• The maximum lift to drag ratio (LDR) of the optimized BWBUG increased by 24.32%.
• The SBSO framework achieved significant improvements with acceptable computational resources.
• The optimization process successfully refined the shapes of all sectional airfoils.

Conclusions:

• The proposed SBSO framework is highly effective and efficient for BWBUG shape optimization.
• This approach offers a superior solution for enhancing BWBUG hydrodynamic efficiency.
• The study demonstrates the practical applicability of advanced optimization techniques in underwater glider design.