8.2 aerodynamics Flashcards
what is turbulent air?
air moving through a disturbance
it becomes turbulent when the air separates
what is laminar flow?
smooth regular air flow
air particles have a mass so what does this result in?
air in motion possesses a momentum
what does air exert pressure on?
on any objects in its path
what is the relationship between dynamic pressure density and velocity?
it is proportional to density and the square of velocity
what is energy due to and what is the equation for that?
due to kinetic energy
KE = 1/2 *v^2
what happens when a volume of air is completely trapped and brought in an open ended tube?
total energy remains constant and the moving air exerts pressure on the tube and kinetic energy is passed
what can and can not be done to energy and mass?
can be neither be created or destroyed
can only change states
what is streamline / free stream?
when particles of a fluid move in an orderly manner and maintain relative position in successive cross section
what is cross section represented by?
lines running parallel to one another hugging the shape of the body it is following around
in the subsonic region a flying body does not attain what?
the speeds necessary to compress the air
where is the air incompressible?
in the subsonic region
if there is no disturbance the air is what?
air is streamline and parallel
when something is streamlined it is what?
it is similar to the flow in a closed tube
what happens when the tube gets smaller in laminar flow?
the air flow remines equally spaced when it is in a tube with different diameter’s
what does the continuity equation state?
that the speed of the airflow is inversely proportional to the cross section if density remains the same
p1 = p2 so v1 * a1 = a2 * v2
when will v1 * a1 = v2 * a2 be used?
when there is a difference in volume
when is there a diffuser outlet?
when diameter increases and speed decreases
when is there a jet outlet?
when the diameter decreases and speed increases
in Bernoulli’s principle what happens when the valve is closed?
the tube is filled with fluid on the left side of the valve
when the valve is closed what pressure will there be and where?
the fluid filled on the inside of the tube has static pressure
in Bernoulli’s principle when the valve is closed where does pressure act?
acts in all directions
what is total pressure represented by in Bernoulli’s principle?
a green circle
in Bernoulli’s principle what is the relationship between total pressure and static pressure when the valve is closed?
total pressure is equal to static pressure