Efficiency of a propeller is defined as the ratio of available power to the engine power which is. . (3). Note, that this definition for efficiency contains the velocity v, which means, that the efficiency approaches zero as the flight speed goes to zero, because the thrust cannot become infinitely large. So this definition is not useful for the special case of static thrust.
1 Compound Fracture: A compound fracture is a fracture in which the injured bone sticks through the skin. 2  Also known as an open fracture, a compound fracture can be a bit more serious in nature.
In an open fracture, the ends of the broken bone tear the skin. When the bone and skin are exposed, they are at risk of infection. This type of fracture is also called a compound fracture. In a closed fracture, the broken bone does not break the skin. broken bone can be described as a: 1  nondisplaced fracture: The bone is broken into pieces that can be aligned in place. 2  displaced fracture: The bone is broken into pieces that donât align. 3  hairline fracture: The bone is broken in a thin crack. 4  single fracture: The bone is broken only in one place.