Rotor blades

Abstract

The article of the present design relates to a lift-type rotor blade fixed in large numbers to the hub periphery of the horizontal rotor of a windmill or water turbine. The front view is a front view of the rotor blade with the wing tip facing upward, and the remaining drawings are based on this. The main feature of this rotor blade is that the wing tip is greatly bent to the right in the front view, and the rear surface and the wing tip surface during rotation appear horizontally long from the front. Next, when viewed from the left side, which is the direction of rotation, it appears wide, but when viewed from the cross section, it is found to be oriented at an angle, making it easy for the airflow hitting it from the front to pass toward the rear. In addition, in the left side view, the wing tip protrudes thinly toward the front, so that the airflow hitting the front of the rotor blade during rotation is embraced by the wing tip, preventing the airflow from dissipating to the side. In the plan view, the trailing edge of the wing tip surface is pointed to the right, and the leading edge is inclined toward the front from the leading edge to the trailing edge with respect to the direction of rotation (to the left in the figure), so the airflow passing through this wing tip passes toward the center of the back surface. As shown in the horizontally long wing tip surface in the front view and the cross section, the front surface of the rotor blade that faces the direction of rotation (to the left in each cross section) is greatly bulged, and the rear surface of the rotor blade is almost flat. Therefore, as shown in the reference oblique view of the rotor showing the usage state, when many rotor blades are used as a horizontal axis rotor, the airflow that hits the rear surface of the rotor blade pushes it in the direction of rotation between two adjacent rotor blades, increasing the air pressure on that surface. The front surface of the rotor that faces that surface becomes negative pressure due to the Coanda effect as it rotates, and the airflow that passes at high speed passes by. This airflow with high air pressure is dragged by the high-speed airflow of negative pressure and passes at high speed toward the back surface. Due to this natural phenomenon, even if there are a large number of blades, there is no interference with the airflow, and the air passes at high speed due to the Coanda effect, resulting in efficient high-speed rotation of the horizontal rotor, which is why it is used in wind turbines, hydroelectric power generators, etc.

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