Aerodynamic efficiency of recently suggested design of wind power plant called Wind Energy Marine Unit (WEMU) with large cross-flow water-supported rotor having rotary blades is found out. Aerodynamic coefficients of chosen airfoil of WEMU blades are derived by 3-D Navier-Stokes numerical simulation. Preliminarily calculated angles of blades'' rotation are corrected after simulation of flow through the turbine. Power coefficient is investigated as a function of the turbine''s solidity and the ratio of velocities. It is shown that power coefficient comes close to Betz limit. WEMU''s rated power capacity can be more than 10 MW. Power loss due to blades'' rotation is evaluated.
A: turbine cross section area = 2RH b: blade width (chord) CD: drag coefficient of a blade CL: lift coefficient of a blade CP: power coefficient of the turbine H: blade height (span) k: turbulence kinetic energy Mi: torque of blade i about the turbine''s axis (i = 1…n) Mоi: torque of blade i about the axis of its rotation MW: total aerodynamic torque of the turbine n: number of blades NL: power loss due to blades'' rotation NW: total aerodynamic power of turbine p: pressure R: radius of the turbine S: blade area = bH u∞: uniform wind velocity far from the turbine (u1, u2, u3): mean absolute velocity (u′1, u′2, u′3): fluctuating component of the absolute velocity i u : ensemble-mean velocity of the incident flow on the blade i (U1, U2, U3): mean relative velocity (U′1, U′2, U′3): fluctuating component of the relative velocity v: linear speed of blades = ωR (x1, x2, x3): position in the stationary coordinate system (X1, X2, X3): position in the coordinate system fixed to the rotor αi: angle of attack of blade i βi: angle of blade i rotation γi: angle between vectors i u and u∞
