Glossary

Aerodynamic drag:
the component of the aerodynamic force generated by the reaction of the surrounding gas of a moving body, in the direction of the relative wind. A distinction is made between frictional drag, wave drag (shock wave at the front) and base drag (depression at the rear).
Aerodynamic focus:
the point of application, on the axis of an aerospace machine, of the resultant aerodynamic forces of lift and drag.
Aircraft:
a vehicle whose lift in the atmosphere is provided by the reaction of the air.
Aircraft load factor (ng):
the aircraft acceleration per g (acceleration of gravity – (9.81 m/s2).
Angle of incidence or angle of attack:
the algebraic value of the angle formed by the projection of the axis OXva of the aerodynamic trihedron on the plane of symmetry XeOZe of the gear trihedron and the reference axis OXe of this last trihedron.
Boundary layer:
a layer of a moving fluid in the vicinity of a wall in which, due to the viscosity of the fluid, the free flow equations are not directly applicable.
Center of gravity:
the point of application of the resultant of the external forces exerted on all parts of a body by a gravitational field.
Center of inertia:
the point of application of the resultant of the inertial forces of a body subjected to an acceleration field.
Center of mass:
the barycenter of the elementary masses of a body.
Center of thrust:
the point of application of the resultant of aerodynamic forces.
Control chain:
a set of equipment that ensures the development of the piloting orders of a machine and their transformation into mechanical action.
Correlation:
the interdependence between quantitative or qualitative observations, highlighted by statistical analysis.
Detachment:
the characteristic of a fluid flow that departs from the wall it runs along.
Drag:
a component, following the direction of speed, of the forces that oppose the advancement of the aircraft.
Euler angles:
Euler angles define the position of the aircraft trihedron M with respect to the local geographic trihedron L in which the vector g has as components (0, 0, g).
Geoid:
a representation of the Earth’s surface that is more precise than the spherical or ellipsoidal approximation. It corresponds to an equipotential (in the field of terrestrial gravity) and is defined in such a way as to stick as closely as possible to the “real area”. On Earth, any point undergoes an acceleration of gravity g. This acceleration derives from a gravitational potential W, such that image The surfaces where the potential of gravity W is constant are equipotentials of gravity. A geoid is an equipotential surface of gravity close to the mean sea level.
Gravitation:
a physical phenomenon whereby bodies attract each other in proportion to their masses and inversely to the square of their distance.
Gravity:
the gravitational force exerted by an astral body on another body.
Hinge moment:
the moment resulting from aerodynamic forces exerted on a steerable control surface, with respect to the axis of rotation of the latter.
Inertial unit:
a precision mechanical and electronic assembly comprising sensitive components (accelerometers, gyrometers) as well as calculation means, capable of supplying the position coordinates and components of speed and acceleration of the machine at any time.
Leading edge:
the anterior part of a wing profile where the airflow divides into the lower surface flow and the upper surface flow.
Lift:
a component, perpendicular to the relative wind, of the aerodynamic force generated by the reaction of the surrounding gas of a moving body.
Navigation:
the art of driving an aeronautical vehicle to a given destination by determining its position, calculating the optimal trajectory and guiding it.
Piloting:
the act of controlling the orientation and the speed of an aeronautical vehicle.
Pitch:
the movement of a body around the pitch axis, perpendicular to the roll axis (for an airplane, the pitch axis is by convention an axis perpendicular to its plane of symmetry).
Relative wind:
the speed of a gaseous fluid relative to a body immersed in it.
Remote control:
the elaboration and remote transmission of a signal carrying an order.
Roll:
the movement of a body around the so-called roll axis (for an airplane, a drone or a rocket, the roll axis is by convention the longitudinal axis).
Rotation:
the circular movement of a body around an axis passing through the body’s center of mass.
Steering:
the terminal part of a control chain, which acts on the flow of the ejected fluid or the surrounding fluid.
Structure:
a set of rigid elements that determine the shape of an aircraft and its ability to withstand mechanical and thermal stresses.
System:
a functional whole the parts of which are interconnected and exchange matter, energy or information.
Telemetry:
the elaboration and remote transmission of a signal carrying a measurement result.
Thrust axis:
the axis carrying the resultant of the propulsive forces.
Tracking:
the remote, instantaneous and continuous determination of one or more characteristic variables of an aircraft generally linked to its movement.
Trailing edge:
the rear part of a wing profile where the intrados and extrados flows meet.
Trajectography:
an operation that consists of tracing or subsequently reconstituting the trajectory of an aircraft.
Trajectory:
a curve described by the center of mass of a moving body.
Wind tunnel:
a test installation in which the flow of a gas makes it possible to study the aerodynamic or ballistic behavior of a body placed in this flow.
Yaw:
the movement of a body around the yaw axis, perpendicular to the pitch and roll axes.
..................Content has been hidden....................

You can't read the all page of ebook, please click here login for view all page.
Reset