1. REPORT DATE 2. REPORT TYPE July 2015 Briefing Charts July 2015-August 2015 · 2016-03-29 ·...
Transcript of 1. REPORT DATE 2. REPORT TYPE July 2015 Briefing Charts July 2015-August 2015 · 2016-03-29 ·...
REPORT DOCUMENTATION PAGE Form Approved
OMB No. 0704-0188 Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing this collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden to Department of Defense, Washington Headquarters Services, Directorate for Information Operations and Reports (0704-0188), 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS.
1. REPORT DATE (DD-MM-YYYY) July 2015
2. REPORT TYPEBriefing Charts
3. DATES COVERED (From - To) July 2015-August 2015
4. TITLE AND SUBTITLE Effect of Surface Omniphobicity on Drying by Forced Convection (Briefing Charts)
5a. CONTRACT NUMBER In-House
5b. GRANT NUMBER
5c. PROGRAM ELEMENT NUMBER
6. AUTHOR(S) Madani Khan, Jeffrey Alston, Andrew Guenthner
5d. PROJECT NUMBER
5e. TASK NUMBER
5f. WORK UNIT NUMBER
7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION REPORT NO.
Air Force Research Laboratory (AFMC) AFRL/RQR 5 Pollux Drive Edwards AFB, CA 93524-7048
9. SPONSORING / MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSOR/MONITOR’S ACRONYM(S)Air Force Research Laboratory (AFMC) AFRL/RQR 5 Pollux Drive 11. SPONSOR/MONITOR’S REPORT
Edwards AFB CA 93524-7048 NUMBER(S)
AFRL-RQ-ED-VG-2015-313
12. DISTRIBUTION / AVAILABILITY STATEMENT Distribution A: Approved for Public Release; Distribution Unlimited.
13. SUPPLEMENTARY NOTES Briefing Charts presented at STAR Closing Conference; San Jose, CA; 7 August 2015. PA#15451.
14. ABSTRACT Briefing Charts
15. SUBJECT TERMS
16. SECURITY CLASSIFICATION OF:
17. LIMITATION OF ABSTRACT
18. NUMBER OF PAGES
19a. NAME OF RESPONSIBLE PERSON
Kriss Vanderhyde
a. REPORT Unclassified
b. ABSTRACT Unclassified
c. THIS PAGE Unclassified
SAR 26 19b. TELEPHONE NO
(include area code)
661-275-5429 Standard Form
298 (Rev. 8-98) Prescribed by ANSI Std. 239.18
1DISTRIBUTION A: Approved for public release; distribution unlimited. AFRL Public Affairs Clearance #
Integrity Service Excellence
Effect of Surface
Omniphobicity on
Drying by Forced
Convection
Madani Khan
The City College of New York
STAR Program
August, 2015
2DISTRIBUTION A: Approved for public release; distribution unlimited. AFRL Public Affairs Clearance #
Background
• I am from Bangladesh.
• Education: The City College of New York
• Major: Chemistry; Minor: Education.
3DISTRIBUTION A: Approved for public release; distribution unlimited. AFRL Public Affairs Clearance #
Abstract
• Low energy surfaces can strongly repel both oil and water. Recently these
surfaces have been fabricated on various substrates including fabric, aluminum,
stainless steel and many other materials. In this experiment we explore the use of
low energy surface deposition on aluminum alloy, stainless steel and silicon
substrates, to enhance the drying rate of liquids removed from the surface by
forced convection. We control surface roughness by substrate abrasion and by
the growth of Al2O3 nanograss to enhance liquid repellence by use of a
hierarchical texture. Liquid repellence of the substrates is measured by contact
angles of the probe liquids, water and hexadecane. Samples are mounted on a
rigid stage constructed with a flat surface and a regulated air nozzle fixed to
provide flow parallel to the substrate surface. The velocities of probe liquid
droplets placed on the substrates are recorded via high-speed camera as they are
moved by a constant air flow. It is shown that drops on omniphobic and
superomniphobic surfaces move at increased velocity compared to untreated
surfaces, and leave behind less residual liquid, resulting in a faster drying rate. 2-
factor design of experiments (DOE) was implemented to explore the optimum
conditions for a fast drying low energy surface. The use of DOE and the results of
this experiment are merged into a lesson plan developed for 9th-12th grade
students. These results will serve as examples low energy surfaces and their
potential applications.
4DISTRIBUTION A: Approved for public release; distribution unlimited. AFRL Public Affairs Clearance #
Introduction
• Explore the use of low energy surface deposition
on aluminum alloy, stainless steel and silicon
substrates, to enhance the drying rate of liquids
removed from the surface by forced convection
• The velocities of probe liquid droplets placed on
the substrates are recorded via high-speed
camera as they are moved by a constant air flow
• 2-factor design of experiments (DOE) is
implemented to explore the optimum conditions
for a fast drying low energy surface
5DISTRIBUTION A: Approved for public release; distribution unlimited. AFRL Public Affairs Clearance #
Application
• The application of this work can be used in rocket
engines, rooftops, cars, umbrellas, tiles, oven,
paint, or any kind of fabrics.
6DISTRIBUTION A: Approved for public release; distribution unlimited. AFRL Public Affairs Clearance #
Design of Experiment (DOE)
• Systematic method to determine the relationship
between factors affecting a process and the
output of that process.
• Why?
– Saves time
– Lower cost
– Reduce product material and labor complexity
– Better design engineering
• Accessibility
– Microsoft Excel or online software
7DISTRIBUTION A: Approved for public release; distribution unlimited. AFRL Public Affairs Clearance #
Substrates
Stainless Steel Aluminum Silicon Wafer
8DISTRIBUTION A: Approved for public release; distribution unlimited. AFRL Public Affairs Clearance #
Roughness Values
Roughened Surface Crossly Sanded with Grit Size 2000Ra-Roughness Average (499.97nm) Rq- Root Mean Square (624.58 nm)Sm- Surface Material Volume (26.36 nm3/nm2)Sv- Surface Void Volume (66.06 nm3/nm2)
9DISTRIBUTION A: Approved for public release; distribution unlimited. AFRL Public Affairs Clearance #
Contact Angle
AFR .!-;i
10DISTRIBUTION A: Approved for public release; distribution unlimited. AFRL Public Affairs Clearance #
Gas-Flow System
.... ~
• •
0"YI(~~ 'I " 'NI'I '=:131~ "" ~ .. a. " a• tf • t ..... •
lrrllllllllrrrl l LJJ-IIrrrrlrrr rlrw 11111 I ""''''' 'rrruJ 1 w IIU11~
AFR .!-;i
11DISTRIBUTION A: Approved for public release; distribution unlimited. AFRL Public Affairs Clearance #
High-speed Video
• ~~I o em 1
0N\1'1'9N3 Nl 3Q'ir4
AFR .!-;i
12DISTRIBUTION A: Approved for public release; distribution unlimited. AFRL Public Affairs Clearance #
Result
0.7
0.75
0.8
0.85
0.9
0.95
2 min 5 min
Tim
e (
sec)
Boiling Time
Boiling Time vs. Drying Time
sec/cm
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
Grit 1200 Grit 320
Tim
e (
sec)
Roughness
Roughness vs. Drying Time
sec/cm
13DISTRIBUTION A: Approved for public release; distribution unlimited. AFRL Public Affairs Clearance #
Conclusion
• Lower roughness leads to faster drying time.
• An irregular surface can cause pinning regardless
of silanization and contact angle, which disturbs
the trend of hysteresis.
• Higher boiling time leads to faster drying time.
• Water has a faster drying rate than hexadecane.
14DISTRIBUTION A: Approved for public release; distribution unlimited. AFRL Public Affairs Clearance #
Lesson Plan
• This lesson plan is directed for 9th-12th grade
students.
• Reading about ice-cream.
• Learning to make ice-cream through a DOE
optimization.
• The three factors are different weight percent of
salt per ice, fat content in dairy and shaking time.
• Measured output will be rating and average of
different ice-creams.
15DISTRIBUTION A: Approved for public release; distribution unlimited. AFRL Public Affairs Clearance #
Future Work
• Different type of liquids
• Durability
• Using the optimization from DOE to further
explore factors.
16DISTRIBUTION A: Approved for public release; distribution unlimited. AFRL Public Affairs Clearance #
Acknowledgement
• Funding and support was received by the STAR program and thank you to
the AFRL for a great research experience. Thank you to Dr. Jeffrey Alston and
Dr. Andrew Guenther for all their guidance and encouragement throughout
this the project. And a special thanks to my fellow STAR student: Nicholas
Rubel.
17DISTRIBUTION A: Approved for public release; distribution unlimited. AFRL Public Affairs Clearance #
Questions?
Questions? AFR IY i ,
18DISTRIBUTION A: Approved for public release; distribution unlimited. AFRL Public Affairs Clearance #
Flow System
Al Substrate Flow CellAFR .!-;i
19DISTRIBUTION A: Approved for public release; distribution unlimited. AFRL Public Affairs Clearance #
Creating Reentrant Surface
Before Sanding
•
AFR .!-;i
20DISTRIBUTION A: Approved for public release; distribution unlimited. AFRL Public Affairs Clearance #
After Sanding
Micro-scale
E llm ,
AFR .!-;i
21DISTRIBUTION A: Approved for public release; distribution unlimited. AFRL Public Affairs Clearance #
Nano-grass Growth
Nano-scale
c llm )
Air
AFR .!-;i
22DISTRIBUTION A: Approved for public release; distribution unlimited. AFRL Public Affairs Clearance #
SEM Image
AFR .!-;i
23DISTRIBUTION A: Approved for public release; distribution unlimited. AFRL Public Affairs Clearance #
Low Surface Energy
Low Surface Energy
E J.lm )
'/ '
AFR .!-;i
24DISTRIBUTION A: Approved for public release; distribution unlimited. AFRL Public Affairs Clearance #
Flow System
Al Substrate Flow CellAFR .!-;i
25DISTRIBUTION A: Approved for public release; distribution unlimited. AFRL Public Affairs Clearance #
Trapping Plastron
1 Dry ..... I I Under WateiJ ......
AFR .!-;i