HYDROKINETIC POWER MODELLING BASED ON LIFT, DRAG, AND THRUST FORCES: APPLICATION OF NACA 4418 HYDROFOIL BLADES

Abstract

Hydrokinetic energy conversion harnesses the kinetic energy of flowing water, eliminating the need for significant hydraulic head, and offers a versatile solution for rivers, tidal streams, and irrigation infrastructure. This study develops a physics-based hydrokinetic power model predicated on the lift, drag, and thrust forces exerted on turbine blades utilizing the NACA 4418 hydrofoil profile. Through the application of classical fluid dynamics and Blade Element Momentum Theory (BEMT), the model derives critical performance metrics, leveraging the NACA 4418 optimized lift-to-drag ratio, structural robustness, and superior cavitation resistance. The resulting framework establishes explicit analytical relationships between incident flow velocity, tip speed ratio (TSR), and turbine power coefficients. Computational assessments across twelve diverse Nigerian locations demonstrate that hydrokinetic potential is fundamentally dictated by monsoonal hydrological cycles, where negligible dry-season hydrodynamic activity transitions into pronounced performance peaks between June and October. This seasonal surge in flow velocity significantly amplifies the aerodynamic loading on the hydrofoil blades, thereby enhancing turbine efficiency and extractable power density. Spatial analysis reveals that while regions such as Owerri, Benin City, Abeokuta, Cross River, and Abuja exhibit sustained power profiles, locations like Enugu and Bauchi are characterized by acute, transient peaks, and Lagos displays a distinct bimodal distribution reflective of the "August Break" meteorological phenomenon. These findings underscore that the viability of hydrokinetic energy systems is contingent upon seasonal flow variability, necessitating deployment strategies that are both geographically tailored and synchronized with localized hydrological regimes.