Docsity
Docsity

Prepare for your exams
Prepare for your exams

Study with the several resources on Docsity


Earn points to download
Earn points to download

Earn points by helping other students or get them with a premium plan


Guidelines and tips
Guidelines and tips

Phase Space and Dynamics: Phase Curves, Portraits, Flow, and Liouville's Theorem, Slides of Applied Mechanics

An overview of phase space concepts in physics, including phase curves, portraits, flow, and liouville's theorem. It covers undamped and damped harmonic motion, phase portraits for lagrangian and hamiltonian systems, and the concept of phase flow. The document also explains the significance of liouville's theorem in conserving the phase space density.

Typology: Slides

2012/2013

Uploaded on 07/26/2013

shareeka_555
shareeka_555 🇮🇳

4

(6)

74 documents

1 / 6

Toggle sidebar

Related documents


Partial preview of the text

Download Phase Space and Dynamics: Phase Curves, Portraits, Flow, and Liouville's Theorem and more Slides Applied Mechanics in PDF only on Docsity!

Phase

Space

Phase

Curve

‐D

Harmonic

motion

can

be

plotted

as

velocity

vs

position.

Momentum

instead

of

velocity

For

one

set

of

initial

conditions

there

is

a

phase

curve.

Ellipse

for

simple

harmonic

Spiral

for

damped

harmonic.

q

p

q

,

UndampedDamped

Docsity.com

Phase

Portrait

•^

A

series

of

phase

curves

corresponding

to

different

energies

make

up

a

phase

portrait.

Velocity

for

Lagrangian

system

Momentum

for

Hamiltonian

system

q

p

q

,

^ E

< 2

E

E = 2

> 2

Phase

Flow

A

region

of

phase

space

will

evolve

over

time.

Large

set

of

points

Consider

conservative

system

The

region

can

be

characterized

by

a

phase

space

density.

dV

N

t^2

t^

t^1

t^

q

p

^

 j

j

j^

dp

dq

dV

Differential

Flow

The

change

in

phase

space

can

be

viewed

from

the

flow.

Flow

in

Flow

out

Sum

the

net

flow

over

all

variables.

j

j

j

j

in

q

dp dt

p

dq dt

^

^

^

^

j j

j j

j j

j j^

p q

p p

q q

p q t

      

  

  

      

   

^

^

^

^

j

j

j j

j

j

j

j j

j out

q

p

p p

p

p

q

q q

q

         

 

  

 

 

   

0    

  

 

  

 

 

 ^ 

j^

j j

j j

j j

j j^

p p

p p

q q

q q

t

q

p

jq

j pj p

j q

Liouville’s

Theorem

Hamilton’s

equations

can

be

combined.

Simplify

phase

space

expression

This

gives

the

total

time

derivative

of

the

phase

space

density.

Conserved

over

time

j

j

p

H q

 

j

j

q

H p

 

0

 

 

j j

j j

q q

p p

0    

  

  

 

^ 

j

j j

j j

p p

q q

t^

0 

d^ ^ dt