lecture_8

lecture_8 - 16.333 Lecture # 8 Aircraft Lateral Dynamics...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: 16.333 Lecture # 8 Aircraft Lateral Dynamics Spiral, Roll, and Dutch Roll Modes Fall 2004 16.333 71 Aircraft Lateral Dynamics Using a procedure similar to the longitudinal case, we can develop the equations of motion for the lateral dynamics v a , u = r x = Ax + Bu , x = p r and = r sec A = Y v Y p Y r m U g cos m m ( I L v + I N v ) ( L p + I N p ) ( L r + I N r ) zx zx I zx I xx xx xx ( I L v + N v ) ( I L p + N p ) ( I L r + N r ) zx I zx zx I I zz zz zz 1 tan where I = ( I xx I zz I 2 xx zx ) /I zz I = ( I xx I zz I 2 zz zx ) /I xx I = I zx / ( I xx I zz I 2 zx zx ) and ( m ) 1 ( I xx ) 1 I zx Y a Y r B = L a L r zz ) 1 zx ( I I N a N r Fall 2004 16.333 72 Lateral Stability Derivatives A key to understanding the lateral dynamics is roll-yaw coupling . L p rolling moment due to roll rate: Roll rate p causes right to move wing down, left wing to move up Vertical velocity distribution over the wing W = py Leads to a spanwise change in the AOA: r ( y ) = py/U Creates lift distribution (chordwise strips) 1 L w ( y ) = U 2 C l r ( y ) c y dy 2 Net result is higher lift on right, lower on left Rolling moment: b/ 2 b/ 2 L = L w ( y ) ( y ) dy = 2 1 U 2 b/ 2 C l py 2 c y dy L p < b/ 2 U Key point: positive roll rate negative roll moment. L r rolling moment due to yaw rate: Positive r has left wing advancing, right wing retreating Horizontal velocity distribution over wing U = U ry Creates lift distribution over wing (chordwise strips) 1 1 L w ( y ) U 2 C l cdy ( U 2 2 U ry ) C l c y dy 2 2 Net result is higher lift on the left, lower on the right....
View Full Document

Page1 / 13

lecture_8 - 16.333 Lecture # 8 Aircraft Lateral Dynamics...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online