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.
A fracture is a broken bone. It can range from a thin crack to a complete break. A bone can fracture crosswise, lengthwise, in several places, or into many pieces. Typically, a bone becomes fractured when it is impacted by more force or pressure than it can support. 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.