Comparison of design methods for negative pressure gradient rotary bodies: A CFD study

Area of Science:

• Fluid dynamics
• Hydrodynamics
• Aerodynamics

Background:

• Laminar flow separation significantly increases drag and noise in hydrodynamic and aerodynamic applications.
• Existing body design methods have limitations in effectively suppressing flow separation.
• Controlling negative pressure gradients is a key strategy for drag reduction.

Purpose of the Study:

• To evaluate two distinct body design methodologies for suppressing laminar flow separation.
• To assess the effectiveness of these methods in achieving drag reduction.
• To identify a superior design approach for hydrodynamic applications.

Main Methods:

• Utilized computational fluid dynamics (CFD) with the Transition SST steady-state model.
• Calculated pressure distribution, wall shear stress, and drag coefficient at zero angle of attack.
• Analyzed four bodies designed using two different methods across various velocities.

Main Results:

• The first design method demonstrated superior drag reduction compared to Hansen's body.
• Bodies designed by the first method effectively suppressed or eliminated flow separation.
• Improved laminar flow coverage was achieved, leading to drag reduction at higher Reynolds numbers.

Conclusions:

• The negative pressure gradient method is more effective for separation suppression and drag reduction than the second method.
• The successful design method offers a promising approach for low-drag, low-noise hydrodynamic hull and underwater weapon design.
• This research advances the understanding of flow control for enhanced vehicle performance.