## 3 Results and Discussion
This trend indicates that as the turbine continues to rotate, the current drawn by the motor decreases proportionately. Despite the constant rotational speed of the motor, the decrease in motor current suggests enhanced power extraction by the turbine propeller blades from the water flow. This inverse relationship between motor current and power generation efficiency highlights the turbine's ability to harness kinetic energy from the water effectively. The fluctuations in the motor current waveform directly reflect the performance and power generation capacity of the scaled turbine model. These results imply that as the turbine blades become more effective in capturing and converting the kinetic energy of the flowing water, less electrical current is required to maintain the motor's rotational speed. This efficiency can be crucial for optimizing the design and operation of hydrokinetic turbines, particularly in applications where maximizing power extraction is essential. Figure 5: The experimental rotational speed profile of the PMDC motor throughout the towing operation. Future research could focus on exploring the effects of varying towing velocities and blade designs on the motor current waveform. Additionally, employing advanced computational models to study the flow dynamics around the turbine blades could provide deeper insights into the mechanisms of energy transfer and conversion, ultimately guiding the development of more efficient hydrokinetic turbine systems. Figure 7 shows a graphical representation of the generated power across different carriage speeds during the experimental testing of the scaled hydrokinetic turbine. The measurements were conducted by towing the turbine model at varying carriage speeds, ranging from 0 to 6.5 ft/s (0 to 1.98 m/s). The rotor propeller operated at a consistent rotational speed of 500 rpm, with the input voltage maintained at approximately 12 V. Notably, the voltage amplitude showed minimal fluctuations throughout the towing test. The graph depicts the fluctuations in the generated power output of the hydrokinetic turbine across the different carriage speeds. The maximum recorded generated power reached 16.7 W, with this peak output observed when the turbine was towed at a velocity of 1.98 m/s. However, despite achieving a peak power output of 16.7 W, the overall performance of the turbine did not meet the optimal expectations. This suboptimal performance can be attributed to the implementation of a planetary gear-head to achieve a slow driving mechanism within the scaled turbine. While the gear-head effectively reduced the turbine's rotational speed as intended, it was not originally designed for use as a generator and therefore presented some drawbacks. The gear-head introduced inefficiencies, leading to reduced efficiency in power generation. Despite this suboptimal performance, the experiment exhibited stable body disposition and consistent power generation. The consistent power output, despite the gear-head inefficiencies, suggests that the turbine model maintains stable operation under varying towing speeds. This stability is critical for practical applications, where fluctuating water flow conditions can impact performance. Figure 8 illustrates how the average generated power changes as the carriage speed increases from 0 to 2 m/s when comparing both the experimental and blade Element Momentum (BEM) simulation results. The generated power serves as an indicator of the system's power output, where an underwater current turbine converts fluid flow kinetic energy into electrical energy. Figure 6: The experimental measurements of the motor current during the towing tank testing. Both the experimental findings and the BEM simulation results indicate a consistent trend: as the carriage speed increases, the generated power also increases. This observation aligns with theoretical expectations, as increased fluid speed translates to greater energy available for the turbine blades to harness.