Dynamics of Thread Movement in Turbulent

Flow FieldJames HallendorffSuman Sinha RayAlexander L. Yarin

Investigate instability mechanism in melt blowing

Motivation

Used to measure Lagrangian motion

Initial setup

Lagrangian Results

Lagrangian Results

Eulerian Behavior

Fast Fourier Transform

Eulerian Results

FFT Results

Harmonics Many harmonics, few that make a difference

Is This Chaotic??

Determine correlation between string length and snapping length or air velocity and snapping length

Snapping Point

Gravity causes artificial snapping point-makes unreliable results

New setup

Snapping point error

Vertical Setup

5 10 15 20 25 30 350

2

4

6

8

10

12

30 Bar String Length vs. Snap Length

3.5x

String Length

Snap

Len

gth

Width to Length Ratio

Using a fixed-length criteria skews results Compare ratios of width to snapping length

Revised Measurement Strategy

8 10 12 14 16 18 20 220

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0.08

Calculated RatioJudgment Ratio

String Length

Ratio

Use the frequencies found in the FFT to augment theoretical model

Analyze the movement of the string in a vertical position

Use polymer solution to simulate melt blowing and to compare it to the thread movement model

Future Work

Conclusion: 2 months is not enough

"MELT BLOWN TECHNOLOGY." UT Knoxville | College of Engineering. Web. 16 July 2009. <http://www.engr.utk.edu/mse/pages/Textiles/Melt%20Blown%20Technology.htm>.

EEC-NSF Grant #0755115 Dr. Takoudis Dr. Jursich Qian Tao

Acknowledgements