Numerical analysis of a turbulent flow with Coanda effect in hydrodynamics profiles

Abstract

In the naval industry, hydrofoils are used for generating lift in low-friction vessels, minimizing drag forces between the surrounding fluid and the hull. These devices are also applied to keep stability and maneuverability for high-speed vessels. A recent technology based on Coanda effect for flows over hydrodynamic profiles has been developed for the application of this equipment to increase the flow, converting lifting forces into propelling ones, aiming to attend the industry interest for developing improved nautical propulsion mechanisms. The main purpose of the present work is to simulate the main operational principle of a hydro-propulsion device based on the Coanda effect. More precisely, a turbulent water flow in two hydrodynamic profiles is considered. The mass flow rate of water in the device is thoroughly studied in this work, solving numerically time-averaged conservation equations of mass and momentum with Computational Fluid Dynamics (CFD) code based on the Finite Volume Method (FVM). To tackle with closure modeling for turbulence it is employed the standard k - ε model. The effect of distance between two hydrodynamic profiles over the mass flow rate is also studied. Results obtained here show that the multiplying effect is noticed in water flow in the region between two hydrodynamic profiles, which is similar to previous findings of the literature for the air flow through aerodynamic profiles submitted to Coanda effect.

Keywords

• coanda effect
• hydropropulsion
• flow amplification
• cfd