15.1 fundamentals Flashcards
what is the two classifications of energy
- potential
- kinetic
what is potential energy defined as
being energy at rest, or energy that is stored
what is kinetic energy defined as
being energy in motion
what are newtons three laws of motion
first law - law of inertia
second law - F = M x A
third law - the law of action and reaction
what is the measuring unit for force
pounds (lbs)
what is the thrust if the engine expressed in
pounds
what is the formula to calculate work
Work = force x distance
what is the calculation for power
Power = force x distance / time
what is acceleration defined as
the rate of change of velocity
what does speed refer to
how fast an object is moving
what does velocity describe
the speed of an object and the direction it is moving
what is the formula for kinetic energy
kinetic energy = 1/2 x Mass x Velocity
what is the brayton cycle the name given to
the thermodynamic cycle of a gas turbine engine that produces thrust
what is the variable-volume constant pressure more commonly know as
continuous combustion cycle
what are the four stage of the continuous combustion cycle
- intake (suck)
- compression (squeeze)
- expansion (bang)
- exhaust (blow)
what are the four ideal changes of state
- isobaric
- isochoric
- isothermal
- isentropic
what two of the ideal change of state are of importance for aircraft gas turbine
- isobaric
- isentropic
what does isothermal refer to
constant temperature
in the brayton cycle what is the process from 2 to 3
isobaric heating (combustion process)
what are the two different types of aircraft engines
- piston type engine
- gas turbine engine
what are the four types of gas turbine engine used on aircraft
- turbojet
- turbofan
- turboprop
- turboshaft.
what are the advantages of turbojet engines
- relatively simple design
- capable of very high speeds
-takes up little space
how much thrust does a turbofan engine produce
80% of the thrust from the engine
turbo-fan engines are manufacture with either what configurations of spool(s)
twin spool and three spool
what does a 3 spool engine consist of
an HP spool, a IP spool and a LP spool
what are the disadvantages of turbo-fan engine
- heavier than turbo jet
- larger frontal area
- inefficient at very high altitudes
what is the primary difference between the turboprop and the turbojet
the additional turbines, a power shaft, and a reduction gear box
what are the advantages of turboshaft engine
- much higher power-to-weight ratio
- typically, smaller than turboprop
