<p>A rotary valve includes: a first airfoil (201) moving downstream when the valve is opened; a second airfoil (202) moving upstream when the valve is opened; a valve body including the first and second airfoils; a shaft (200) for supporting the valve body; and a passage (203) for rotatably accommodating the valve body through the shaft and guiding a fluid, wherein the first airfoil is concaved and/or the second airfoil is convexed. <IMAGE></p>
