AE 3521 Final

45 cards·by wesleyallenfuller

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Static Stability

Initial tendency to return toward equilibrium when disturbed.

Rudder Control Power

Yaw moment per unit rudder control input.

[The function of] Pitot Static Tube

For measuring the difference in total pressure (or stagnation pressure) and static pressure.

[The function of] Elevator

Pitch control.

[The function of] Wing Dihedral

Roll Static Stability

[The function of] Vertical Tail

Directional Static Stability.

[The function of] Vertical Tail

Directional Static Stability.

The most forward center of gravity limit is dictated by:

Elevator Control Limit

Aft most center of gravity limit is dictated by:

Longitudinal Static Stability.

Which of the following does not affect the neutral point location? a) Lift curve slope of the wing b) center of gravity c) wing aero center?

b) Center of Gravity

Adverse yaw in a banked turn is due to:

Aileron deflection

Adverse Yaw

A yawing moment created by the ailerons during a turning maneuver that opposes the turn.

Angular Momentum

Moment of Liner Momentum

Stability Axis

Specific body axes with ZERO equilibrium angle of attack.

[Primary contributor to] Pitch Damping

Horizontal Tail (Elevators)

[Primary contributor to] Yaw Damping

Vertical Tail (Rudder)

[Primary contributor to] Roll Damping

Wings (Aileron)

[Primary contributor to] Roll Stiffness

Wing Dihedral

For a body with yz plane of symmetry, which products of inertia are zero?

I_yx and I_xz

How many state variables are required to fully describe the dynamics of an aircraft idealizedas a rigid body?

12 (x y z, p q r, l m n, u v w)

The pitching moment derivative with respect to time rate of change of angle of attack is included in the linearized model to account for:

Time lag in the wing downwash effect at the tail

Role Rate, Pitch Rate, Yaw Rate

p, q, r

Dynamic Stability

A system when disturbed from equilibrium returns to equilibrium in time

Root Locus

Locus of closed loop system poles in the complex plane for varying values of controller gain

[derivative] Short period mode damping ratio

Pitch Damping Derivative M_q

[derivative] Spiral Mode Stability

Roll Static Stability Derivative L_beta

[derivative] Dutch roll mode natural frequency

Yaw Static Stability Derivative N_beta

[Derivative] Phugoid Mode

Speed Damping Derivative X_u

Which variable does not play any role in the open loop stability analysis of an aircraft?

Any control input. Ex: Rudder input

Which out of the following variables is ignorable for open loop stability analysis of anaircraft?

Yaw Attitude

When non-dimensional variables are used in place of dimensional variables

eigenvectors are different

What is the limitation imposed by the zero in the right half plane on the controller design?

Closed loop is unstable beyond certain value of controller gain

hich would you consider for meeting only a Dutch roll mode?

Yaw Rate Feedback into rudder with a washout filter

hich feedback would you consider for meeting only a roll mode

Roll rate feedback into airleron

Clearly explain why a washout filter is included in the yaw rate feedback.

turns using rudder are characterized by low freq turn rates. Washout filter reduces the opposing effect of yaw rate feedback at low freqcie

If washout filter constant is increased

Max damping ratio is decreased

Polhode

Intersection of Momentum and Energy Ellipsoids

Gravity Gradient Torque

Moment about the center of mass of a body from the distributed gravity forces acting on the body

Which of the following sequences going from the fixed system to the body system is most used in describing spacecraft attitude angles?

z-rotation, x-rotation, z-rotation

For a thin disk spinning about its symmetry axis with 8 nearly zero, the ratio of precession rate to spin rate is

For an oblate body, the spin rate and precision rate are in

opposite sense

For a rigid body spinning about the minor axis, the intersection of momentum and energy ellipsoids are

two points

For spin stabilization of a prolate dual-spin satellite

the energy dissipation rate of the platform must be greater than that of the rotor.

Control moment gyro is a device used for

applying moment about an axis perpendicular to the gyro spin axis

Momentum wheel is a device used for

applying moment about the momentum wheel spin axis (