Heat Captured in a

Marching Band UniformCassidy Laird

BE 4120 Final Project

Overall Outward Effect

Credit for photo: John Bolton Photography

Why? Observations – uniforms cause members to feel

extremely warm – heat exhaustion is common

Winter time – acts as extra layer of clothing, often have

to wear many layers

How much does the uniform actually affect this?

Solving Analytically

0. See right

1. Human, with and

without uniform

2. Flat plate

3. x direction – assumed to be width (front to back)

4. Assume no bulk flow in/out; heat transfer by conduction

and free convection at surface

Credit for image: Tiger Band Media

Continued 5. BC 1: Convection at surface:

BC 2: Symmetrical temperature profile assumed:

6. Heat generation – assume constant for relative time

frame

7. Thermal conductivity (k) assumed constant

8. Assumed steady state (short time frame)

9.

10. Solve for unknown – temperature at surface of skin with

and without uniform (for all work, see Appendix)

Final equation:

Solution Analytically – without: 24.6°C; with: 24.8°C

Numerically – used COMSOL model

W/o – theoretically says 37°C

W/ - range of ~304-311 K (31-38 °C), Average = 34.5 °C

Experimentation Measured temperature near surface of skin for 30

minutes without uniform and 30 minutes with

Outside temperature: roughly 22-23°C (measured

simultaneously)

Cloudy conditions – disregard solar radiation in

analysis

Used HOBO Data loggers

Imported data and graphed

Figure 1. Temperatures

logged for outside air

(average), and near skin

with and without uniform.

Figure 2. Relative humidity

logged with and without

uniform.

0

5

10

15

20

25

30

35

40

0 5 10 15 20 25 30 35

Tem

pera

ture

[C

]

Time Passed [min]

Without Uniform

With Uniform

Air Temperature

39

40

41

42

43

44

45

46

47

48

0 10 20 30 40

Rela

tiv

e H

um

idit

y [

%]

Time Passed [min]

Without Uniform

With Uniform

Conclusions Final results:

Analytically – 24.8°C (76.6°F) with uniform

Numerical – 34.5°C (94.1°F) with uniform

Experimentally – ~34°C (93°F) with uniform

Increase of ~4°C (7.2°F) with uniform

Numerical & Experimental – 1.5% difference

Averaged COMSOL values, experimental factors

Experimental & analytical – 27% difference

Assumptions made, different method of solving, experimental factor

Special thanks to: Tiger Band for the loan of the uniform

Dr. Caye Drapcho for teaching us this material, and her

aid to me in this project

Jeremiah Davis for help with the HOBOs

https://twitter.com/cutigerband

http://www.clemson.edu/majors/biosystems-engineering

ReferencesDrapcho, Caye. “Lecture 4: Modes of Heat Transfer.” BE 4120. Clemson University,

Clemson. 26 January 2015. Lecture.

Drapcho, Caye. “Lecture 5: SS conduction/convection.” BE 4120. Clemson University,

Clemson. 28 January 2015. Lecture.

Drapcho, Caye. “Lecture 6: SS conduction/convection.” BE 4120. Clemson University,

Clemson. 4 February 2015. Lecture.

Drapcho, Caye. “Lecture 8: Heat Diffusion Equation.” BE 4120. Clemson University,

Clemson. 9 February 2015. Lecture.

Drapcho, Caye. “Lecture 9: Boundary Conditions.” BE 4120. Clemson University,

Clemson. 11 February 2015. Lecture.

Drapcho, Caye. “Lecture 15: Free convection.” BE 4120. Clemson University,

Clemson. Date. Lecture.

Drapcho, Caye. “Introduction to COMSOL.” BE 4120. Clemson University, Clemson.

13 February 2015. Lecture.

Nave. 2014. Thermal Conductivity. HyperPhysics. Georgia State University. Available

at: http://hyperphysics.phy-astr.gsu.edu/hbase/tables/thrcn.html. Accessed

12 April 2015.

Specific Heat. The Engineering Toolbox. Available at:

http://www.engineeringtoolbox.com/specific-heat-solids-d_154.html.

Accessed 11 April 2015.

2015. Polyethylene Terephthalate. Wikipedia. Wikipedia. Available at:

http://en.wikipedia.org/wiki/Polyethylene_terephthalate. Accessed 11 April

2015.

2015. Wool: density in 285 measurement units. Aqua-Calc. AVCalc LLC. Available at:

http://www.aqua-calc.com/page/density-table/substance/wool. Accessed

11 April 2015.

Appendices:Free convection coefficient

Appendices: Integration

Appendices: Integration

Final equation:

Appendices: Temperature Calculation