<p>The Conformal mapping techniques have shown many applications in the two-dimensional environments of engineering and physics, especially in the two-dimensional incompressible flow field that was introduced by Prandtl and Tietjens. These methods show reasonable results in the case of the analysis the local coefficients of the complex airfoils comprehensively.&nbsp;The mathematical form of conformal mapping always locally preserves angles of the complex functions but it may change the length of the complex model. By considering the design of the turbine blades which are the hydrofoils that are divided into 25 individually hydrofoils with decreasing thickness from root to tip. The geometric shapes of these created hydrofoils come from the original FX77W121 airfoil shape and from interpolating between the FX77W121, FX77W153, and FX77W258 airfoil shapes, as the last three digits of this airfoil family approximate the thickness ratio times 1000 (FX77153 =&gt; 15.3 % thickness ratio). Of the 25 different airfoil shapes specified for the optimal rotor, there are 23 unique shapes. This study describes the advantage of using at least two different complex variable techniques of transformation conformal mapping in two dimensions. Conformal mapping technique is used to form a database for sectional lift and drag coefficients based on turbine blade design&nbsp;&nbsp;to be used in Blade Element Momentum (BEM) theory to predict the performance of a three bladed single rotor horizontal axis ocean current turbine (1.6-meter diameter) by considering the characteristics of the sea-water. In addition, by considering the fact that in the real situation of the ocean, the underwater ocean current turbines encounter different velocities, the maximum brake power will be investigated based on different incoming current velocities. The conformal mapping techniques is used to calculate the local lift coefficients of different given hydrofoils with respect to different angle of attacks from&nbsp;&nbsp;-180≤AOA≤+180. Then these results will be compared to the results from other method obtained recently by our research group. This method is considering the potential flow analysis module that follows a higher order panel method based on the geometric properties of each hydrofoil cross section. The velocity and pressure fields are obtained directedly by the applications of the Bernoulli’s principle, then the lift coefficients are calculated from the results of the integration of the pressure field along the hydrofoil surface for any angle of attack. Ultimately, the results of this research will be used further investigation which is the design and build the small-scale experimental ocean current turbine that will be conducting in the towing tank at the University of New Orleans.</p>

Power Estimation of an Experimental Ocean Current Turbine Based on the Conformal Mapping and Blade Element Momentum Theory

Paper Proceedings: https://asmedigitalcollection.asme.org/IMECE/IMECE2021/volume/85543

ASME 2021 International Mechanical Engineering Congress and Exposition (IMECE2021)

Supporting the need among researchers worldwide for additional online and multimedia content, ASME now offers the ASME Conference Video Collection. This platform will collect and provide long-term access to conference presentation videos, encompassing all technology areas within ASME's technical conference and events program. About 30,000-40,000 engineers across all mechanical engineering and related disciplines participate in ASME conferences each year. This includes authors of approximately 6,000 to 8,000 technical papers published by ASME, the majority of whom also submit video presentations for our virtual conferences. The video collection will be available as an add-on to existing product packages or as a separate subscription.