Expert: Mark Janus - 7/29/2007

Question
what is aerodynamics?and what basic things should an aeronautical engineer should know about aerodynamics for his interview?what is fluid dynamics?what aerodynamic forces an airplane has to overcome while it is flying in the air?

Answer
Aerodynamics is the study of the flow of gases (like air).  Fluid dynamics is the study of all moving fluids (gases, liquids, and plasma).
Basically airplanes deflect the air downward to hold (or move) the vehicle in the air.  Unfortunately an undesirable consequence of this process is a component of force parallel to the direction of travel called drag which acts to "stop" the vehicle.  The engines on an airplane are necessary to overcome this force by providing another for called thrust which opposes drag, and thus is used to accelerate the vehicle (or at a minimum keep the vehicle speed constant).

Thanx for your question.
mj