Basic Aerodynamics Flashcards
What is a streamline flow?
The line which shows the direction of a flow in a fluid at any moment.
Mathematically, a line in a fluid field on which the velocity vector is the tangent of the point at any given time.
Streamlines do not intercept.
What are the conditions for Bernoulli’s equation. What does his equation state?
Applies along a STREAMLINE flow of an IDEAL (INCOMPRESSIBLE -below 250kt) fluid that is in a STEADY STATE and FRICTIONLESS. Could add level flow if applicable.
Sum of potential energy, kinetic energy and potential to produce work is a constant.
What is total pressure equal too when v=0m/s
Stagnation pressure
Define an ideal gas
A gas which is free and does not collide with others, will have first order collisions
What is the first law of thermodynamics?
Heat transfer (Q) to/from a system of a fluid equals the sum of the change in internal energy of the gas and the work done/received by the gas... assuming isolated with no mass exchange externally. Q=Eint + W
Is based off energy conservation… that energy can’t be created or destroyed.
Refer to notes for examples
What is isothermal? What are the associated IGL & energy equations?
Equal temp
PV=PV.
P/ro=P/ro
Q=W
What is isobaric? What are the associated IGL & energy equations?
Equal pressure.
V/T=V/T
Tx ro=Tx ro
Q= change Eint + work
What is an isochoric/isovolumetric? What are the associated IGL/energy equations?
Equal volume or density
V/T=V/T
P/ro=P/ro
Q=change Eint
What is adibatic? What are the associated IGL & energy equations?
No heat exchange.
Refer to notes.
Q=0… Eint=-W
What is Eint and work?
Eint is mcT (specific heat equation)
Work is any work done on system, found through volume change (so integrate area under a curve)
What does a pilot tube measure?
Dynamic px
Review Q3b in assignment 1
Actually go and do it
Units for specific heat (for thermodynamics) when either V(ro) or P is constant… which of these shares the same units as Rm?
What about for heat transfer?
Thermodynamics
cV. V is J/molK.
cV. P is J/KgK. This is the same as Rm
Heat transfer
Cv. V(ro) is J/molK
Does increasing V in level flight mean a decrease in Cl?
Not necessarily true… it is true that Cl will have to decrease but increasing V does not directly cause Cl (AoA) to decrease, you lowering the nose does.
What principal does mass flow rate work off?
What are the units for mass and volume flow rate?
Mass conservation (in=out)
M3/S is volume
Kg/s is mass
