This report describes the design and construction of a heat pipe prototype. The goal was to create a heat pipe that could successfully transfer heat between 295-789 Kelvin to cool high-temperature systems. Challenges included designing an effective heat transfer system with limited materials and budget. Technical activities to construct the prototype included cutting pipes, attaching elbow joints, cutting and shaping aluminum fins, and assembling the components. A Creo parametric model and physical prototype were completed to demonstrate the innovative piping design. Although difficult, the project objectives of designing, modeling, and constructing a functional heat pipe were achieved through teamwork and problem solving.

1.
ENGR 103 - Spring 2013
Freshman Engineering Design Lab
Heat Pipe Final Report
Date Submitted: June 5,
2014
Submitted to: John Speidel, speidel@drexel.edu
Group Members: Conor Seery, cps72@drexel.edu
D Yoan L Mekontchou Yomba, Dm3233@drexel.edu
Zainab Dashti, zd48@drexel.edu
Abstract:
​ This Design Project is dependent on the construction of a heat pipe that successfully transfers heat by the
processes of condensation and evaporation. The goal of this project is to master strategic planning
concepts, grasp implementation notions , and apply established problem solving skills to circumstances
that may arise in the fabrication stages of this project. The objective is to complete the prototype with no
miscalculations. There were many technical difficulties faced throughout the course of this project. For
example: the creation of the mathematical model through MATLAB posed an immense problem due to
the fact that thorough and in depth understanding of certain advanced functions weren’t present, different
test performed (stress analyses, evaporation rate, heat dissipation...etc) , the various different trials and
errors experienced while trying to apply the right quota of Methanol inside the pipe ,and gaining
familiarity with machines in the shop were some difficulties that have been faced throughout the final
fragment of this project. This project has held numerous tasks which for the most part supplied numerous
lessons. Such tasks included finishing formatting all pipes, physically cutting a copper sheet into a set of
annular heat fins, and properly creating a balance throughout the pipe in a way that will encourage
evaporation. The final deliverables were probably be the most difficult to accomplish. For example, the
final design project and final presentation were on of the hardest parts of the entire project because they
needed to contain physical/visual representations of the framework and also the various strides taken
throughout the length of this project. These various endeavors were exceedingly difficult to accomplish
but through the mold of teamwork, focus, and ingenuity the fabrication of this pipe has been possible.

2. 1
1​ ​Introduction
1.1​ ​Problem Overview
​ The incentive driving this specific assignment is to educate students about the many different
components that make up engineering projects, which include proposing a plan of action, strategizing,
examining, constructing, calibrating and completing projects. Therefore, this team was responsible for the
creation of a workable prototype able to first withstand intense heat conditions and successfully cool an
object through the transfer of heat from the initial contact site to the opposite end of the pipe. This utensil
had to have been able to withstand and transfer heat between the ranges of 295 Kelvin and 789 Kelvin in
order to successfully cool a high temperature calibration system or an orbit satellite thermal management
system . With heat signatures as high as 789 Kelvin, it makes it increasingly difficult to be able to
accommodate both goals in that the heat is able to be transferred thoroughly and also the heat does not
melt the pipe itself. The use of Copper took care of the second goal but the transfer of heat is one aspect
of the project that posed the most difficult challenges. Cost was another constraint that continuously
resurfaced. With a low budget, it was exponentially hard to acquire the best materials therefore reducing
the quality of the created prototype. Lastly, physical constraints such as length and mass posed a huge
problem as well. Although a bigger more complex pipe may have been more effective in accomplishing
the task at hand, the probability for error would have increased, the pipe may have not been able to
mechanically fit into the certain calibration/thermal management system, and not to mention the limited
time given to achieve completion of this project. This project although completed held some of the most
strenuous tasks. These tasks included debugging code in MATLAB to create a physical and testable
representation of the pipe, cutting the copper sheet into more than six annular shapes for the heat fan,
finishing welding the metal in a right cylindrical pattern, and physically formulating a heat sink and
insulated wrap. The desired outcome was to construct a heat pipe able to withstand and transfer
pressure/heat from end to end in a way that promotes cooling, a task that was previously met with
hesitation.
1.2​ ​Existing Solutions
​A heat pipe unlike most entities is not aided by the force of gravity due to the low heat functions it’s
created for and the fashion in which heat ramification is displayed. On the other hand, methods of passive
heat exchanges based on natural convection which circulates a fluid without the use of a pump are greatly
assisted by the forces of gravity.These passive exchanges(Thermosiphons) were expected to be
incorporated into the pipe since it would tremendously aid the process of heat dissipation.Thermosyphons
were initially anticipated to be incorporated in this through the use of braze since soldering would pollute
the gases working within the prototype but due to the low funding provided it wasn’t made possible. Also,
in order for proper heat dissipation throughout a calibration/thermal management system, the pipe needed

3. 2
to be unblemished and abstain from from having any oils or soot inside as this would pollute the gas
within the pipe so extensive cleaning of the pipe was performed. Lastly, a cold weld was needed to create
a leak tight seal and being that the diameter of the pipe’s fill tube was approximately ⅛” , it was a rather
uncomplicated process.
1.3​ ​Project Objective
This project specialized mainly in the field of thermal or calibration management systems. Due to this
specific specialization, this prototype was created in a matter that allowed it to be physically adapted to
the specific task at hand which is to cool massive machines in the most efficient manner. The pipe created
constitutes of 8 interconnected pipes and 8 more pipes angled at 45 degree angles connected by
rectangular fins. A design as complex as this allows for flexibility of use and allows for a more proficient
pipe. This prototype is scaled down to 1 foot but easily could be expanded to fit into more intricate
systems with the likes of satellites. Normally, heat pipes are assembled in a honeycomb pattern but,
because innovation drives this project, it was decided that this certain prototype had to exhibit an
innovative format. This pipe has been tested for burst pressure verification, liquid leak detection, working
fluid distillation/processing, and is for the most part highly efficient being that this team has been highly
limited in resources, extensive knowledge of heat pipes/processes and experience throughout the course
of this project..
1.31 Deliverables
A 3­dimensional model of the proposed heat pipe was created with the goal of physically modeling the
relationship between parts and materials and the dimensions of each component. A physical model of the
pipe is present as well. Lastly, mathematical model expected to stress, fluid, and heat dissipation analyses
has been dropped due to the level of difficulty it posed and the lack of in depth advanced understanding of
the software.
2​ ​Technical Activities
During the creation of the work plan for the heat pipe, many technical activities were assigned to
be completed in the given time frame. These technical activities represent the practical approach to the
heat pipe project. They involve numerous aspects of the construction of the heat pipe and include many
operations. These operations involve getting the correct measurements for the pipes, fins and other parts,
the meticulous cutting of the pipe into measured pieces, the molding of the caps onto the pipes using a
torch and a silver roll, and the cutting of the fins into either circles or squares. Additionally the processes
of attaching adapters to the pipes, threading the pipes and assembling the pieces also represent the main
technical activities. After these processes were completed, trials were performed on the heat pipe, it’s
dissipation of heat, and its conductivity. To guarantee minimal error, a Creo Parametric model was
created. The creo model has given a visualization of the shape, measurements, and materials used.

4. 3
The Creo Parametric model and the physical prototype have reached completion. Furthermore, the cutting
of the pipes, the attachment of the copper elbows onto the pipes, the cutting of the copper sheet into
calculated squares, the sanding of the edges and the surfacing of the sheets have been completed. The
cutting of the pipes was accomplished using a pipe cutter. The attachment of the copper elbows onto the
pipes was manually done and by physically installing the elbows on the end of the pipe, a torch and a
silver roll were then used to fasten them together. The cutting of the aluminum sheets was achieved using
a bandsaw. The sheets were cut into 16 equal squares. 12 of those sheets are used as fins and the
remaining four were used for trials to minimize error. The sanding of the edges of the aluminum squares
were done using a belt sander. The sides were sanded to smooth them for safety purposes. The surfacing
of the heat fin’s edges, addition of holes in the fins, the fitting of the pipe in the aluminum sheets, the
threading of the ends of the pipe, and lastly the installation of the adapter and methanol were all
performed as well.This prototype is a physical representation of the fact that although any task may be
extremely difficult, anything is possible.
Figure 1. Attaching elbows onto pipe Figure 2. Cutting aluminum sheets using bandsaw
Figure 3.Sanding the aluminum sheet edges.

5. 4
Figure 4. Creo Parametric Model Pipe
2.1​ ​Project Timeline
Tasks 1 2 3 4 5 6 7 8 9 10
Initial
Design
x
Design
Proposal
x
Creo Model x x x
Design
Review And
Revisement
x x x x x

6. 5
Ordering
Materials
x x x
Lab Work
& Machine
Shop
x x x x x
MATLAB
Model
x x x
Testing x x x
Final
Report
Preparation
x x x
Presentatio
n Prep
x x
Table 1: Design Project Timeline
2.2 Project Budget
Category Cost
Copper Pipes, Braided Nylon Polypropylene
Cord, Caps, Threaded Pipe
$50.00
Methanol $16.50
Copper & Stainless Steel Sheet $83.80
TOTAL COST $150.30
Table 2: Freshman Design Project Budget

7. 6
2.3 Material Advantage
2.31 Copper
​Copper holds a melting point of 1083 degrees and has a density of 9 g.cm^3. As a result of this and the
many other characteristics copper possesses, it was chosen as the main component to the heat pipe itself
and makes up the the heat fan entirely .
2.32 Aluminum
​Aluminum is a metal with a melting point that is very high(though not as high as copper) helps provide
additional flexibility in terms of the heat ranges able to be exhibited on the pipe. This metal has the
capability of being melted by reasonable heat signatures yet still have a high enough heat capacity which
make it extremely beneficial especially as a sealing component for the main pipe.
2.33 Methanol
​ Methanol is the best working fluid because it best fits the operating temperatures of the heat pipe. With
a working range of 273 Kelvin to 403 Kelvin it’s the best suited liquid to fully exhibit evaporation and
condensation therefore making it the best suited working liquid.
3​ ​Results
The final deliverables for this project include the Heat Pipes itself, the Creo Parametric visual model and
the heat pipe itself. The Heat Pipe is fully functional and the Creo Parametric model has so far provided
this project with valuable information relating to the size this heat pipe should be and the various other
dimensional constraints expressed.
4​ ​Future Work
This pipe could use additional exertion. Due to the limited time and resources provided, the best work has
not able to be produced. For example, the pipe could be altered in a way that would make it more
complex therefore exponentially speeding up the cooling process. More metals could have been
purchased to aid in the process of heat dissipation. Increased time would allow for more work in the shop
and eventually increasing the quality of this project.There are countless other factors that could play a
huge positive part in this project if cost hadn’t been an issue. Though, this pipe could use more work, it
has a very innovative design, many lessons were learned, and it’s functioning at the highest efficiency.
5​ ​References

8. 7
[1] Thermacore.(1970). Heat Pipe Technology: Passive Heat Transfer For Greater Efficiency[Online].
Available:​http://www.thermacore.com/thermal­basics/heat­pipe­technology.asp​x
[2] Fred Kohl. (2012, Feb. 22). Keeping Cool With Heat Pipes On The Space Station[Online]. Available:
http://www.nasa.gov/mission_pages/station/research/news/heat_pipes.html
[3] ​WiseGeek.(2015,Apr.11). What Is A Thermosyphon[Online].
Available:​http://www.wisegeek.com/what­is­thermosiphon.htm
[4] Instructables.(2015). Heat Pipe[Online] Available:​http://www.instructables.com/id/DIY­Heat­pipe/