Quiz 5

• Is Kutta condition satisfied at a subsonic trailing edge?

  yes
• Can Bonney‘s theory treat tapered trapezoidal wing planforms?

  No
• Can Bonney’s theory handle non-flat plate wings?

  yes
• Can Table 11.1 of B&C handle a wing with the double-wedge airfoil?

  yes
• Is the thickness ratio of the thick airfoils in Table 11.1 fixed?

  no
• Bonney's theory can handle any supersonic flight Mach number and wing aspect ratio, so long as the tip Mach cones are non-

  intersecting
• For an unswept, flat-plate rectangular wing, the region _________ the tip Mach cones is purely 2-D aerodynamics

  Outside
• Name the supersonic airfoil in Table 11.1, with curved surfaces?

  Biconvex
• For a swept airfoil, it is the component of M1 __________ to the LE that generates no aerodynamics

  parallel
• A ___________ LE on a sweptback wing will produce shock waves

  Supersonic
• Is Ackeret's Supersonic Airfoil Theory a nonlinear, large-perturbation theory?

  No
• Does the Cm (Coefficient of moment) of the airfoil generally depend on airfoil AOA?

  Yes
• Ackeret's Theory predicts a location of ____________ for the aerodynamic center


  mid-chord (or 1/2 or c/2)
• For a flat plate airfoil at an AOA, the lower surface is a ___________ surface

  compression (or Cp > 0)
• For a flat plate airfoil at an AOA, the upper surface is a ___________ surface

  expansion ( or Cp < 0)
• Can Ackeret's theory generate the pressure distribution on a thin "supersonic" airfoil?

  Yes
• Can small-disturbance hypersonic flow be linearized?

  No
• Can Ackeret's theory generate the pressure distribution on the airfoil?

  Yes
• Is Ackeret's theory as accurate as Shock-Expansion theory for small angles?

  Yes
• The location of the ___________ (give abbreviation) of the airfoil according to Ackeret's theory is the mid-chord point

  AC
• Can Ackeret's predict Cm about LE point?

  Yes
• Can Ackeret's help us calculate the Cm about any point along the chord line?

  Yes
• Does the Cd of the airfoil depend on airfoil camber?

  Yes
• Does the lift coefficient here depend on AOA?

  Yes
• For a flat plate airfoil at an AOA, the _______ surface is an expansion surface

  Upper
• For a flat plate airfoil at an AOA, the _________ surface is a compression surface

  Lower
• Give the general formula for Xcp in terms of Cl and CM_LE, where the latter is + nose up

  Xcp = -Cm_LE/Cl
• Are we to enforce the Kutta condition at a supersonic trailing edge?

  No
• Can Bonney's theory treat a wing with swept trapezoidal planform?

  No
• Can Bonney's theory handle wings with NACA 0012 airfoil section?

  No
• Can Table 11.1 of B&C handle a wing with a double-wedge airfoil?

  Yes
• Bonney's Theory can handle any supersonic flight Mach number and wing aspect ratio, so long as the tip Mach cones are __________

  Non-Overlapping
• For a swept airfoil, it is the component of M1 ____________ to the LE that generates the aerodynamics

  Normal
• The CFM international RISE stands for

  Revolutionary Innovation for Sustainable Engines
• What is the CFM International RISE?


  An open rotor engine that is currently being developed by CFM International.
• 50-50 joint venture with which two companies?

  GE Aerospace and French Safran Aircraft Engines.
• The engine is planned to support both hydrogen and sustainable aviation fuels, and it plans to achieve a 20% reduction in fuel burn and in carbon dioxide emissions.
• RISE has only a single-stage open rotor
• The two stages of the RISE have variable pitch control
• RISE will also use a recuperator, which captures waste heat from the exhaust gas to pre-heat the air that exits the compressor before it enters the combustor.