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TDMG Newsletter July 11th, 2011
Volume 2, Issue 1
TDMG’s News by
Bruno Zoccali,
President TDMG Inc
TDMG News by Bruno Zoccali, President TD MG Inc
Please ask us your
- Thermal & structural agreement with EDAForce
analysis of acoustic devices questions and give us
to increase its marketing
for industrial and process some newsletter
reach throughout Canada
applications ideas
and North America. We are
- Data center airflow analysis c o nf i d e nt this ne w
Let us know what you
- Airflow analysis of gravity agreement will help us
think about this
ventilators for smelting grow our business to new
The last year has been quite application newsletter
heights.
eventful at TDMG. After an
expected slowdown in 2009 In addition TDMG has In this issue of the
following the financial crisis, entered into agreements newsletter we will cover the
2010 was the re-birth of R&D with two new business following items: thermal
for many of our clients. Our partners to strengthen its interface materials, novel
work has been quite service offerings and data center flooring
varied—here are a few increase market visibility. system, and finite element
examples: In June 2010 TDMG stress & buckling analysis
- Design of a wrist worn
signed a collaboration for a shelving rack. I hope
device for tracking children agreement with Design1st you enjoy these topics.
and the elderly (an Ottawa-based product Please feel free to suggest
- Transient thermal
design firm) allowing both anything else that may be
characteristics of a thermistor companies to enhance of interest to you.
sensor for monitoring height each others services and
of fluid in grease interceptors provide presence in their
- T hermal analy sis of resp ect ive reg io na l Inside this issue:
conduction cooled markets. In April 2011,
communications equipment TDMG signed a business TDMG News 1
Novel Data Center 1
Novel Data Center Flooring System Flooring System
TDMG has been working these rooms must be Units located in an adjacent Thermal Interface 2
with Interstitial Systems to properly cooled to mechanical equipment room. Considerations
optimize the efficiency of manufacturers’ stringent TDMG has provided
their unique multi-level specifications for proper significant CFD data Finite Element 3
raised floor distribution operation and longevity. demonstrtaing the efficiency Stress & Buckling
system for Data Centers. Typically, rooms have been of the system in comparison Analysis for a
Data Centers are used to cooled with very costly to conventional single level Shelving Rack
house IT Equipment for CRAC units around the floors, and helped to
everything from banking perimeter of the room optimize the AHU’s
systems, to air traffic control consuming valuable space operation in a Central
Interstitial System
centers. The last decade that would otherwise be Station application, thereby,
has seen tremendous used by additional IT saving 46% of a specific
increases in energy equipment. 9,000 sq ft room’s operating
consumption by data energy (over $300,000
Interstitial’s pressurized
centers, and now represent annually).
system provides ventilation
up to 2% of the world’s
effectiveness, allowing For additional information
energy consumption.
owners to use much larger, please contact us or
The high heat dissipation more cost effective and Interstitial Systems directly.
from this equipment means energy efficient Air Handling
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2. Page 2 TDMG Newsletter July 11th, 2011 Volume 2, Issue 1
Surface Irregularity
Thermal Interface Considerations
Thermal interface considerations can be very important in cooling of electronic equipment.
Firstly why do we use thermal interface materials. As can be seen on the figure at the left,
typical materials have surface irregularities which prevent perfect contact between faces. In
such examples the simple solution is to apply a “grease’ type material which will fill those air
gaps and provide better thermal contact between the faces.
But that is not the only reason for the use of thermal interface materials. For example, if we
“Thermal interface have one heatsink touching multiple components of different height, we could not guarantee
contact on all faces unless the heatsink base was machined to match. Even then, the
considerations can
tolerances would make it such that we could still not guarantee perfect contact on all
be very important components. In such cases, we could use a flexible material that would allow the heatsink to
fully contact each component while keeping compression loads to a minimum.
in cooling of
Once it is established that a thermal interface material is required, what is the effect of such a
electronic material. By definition, conduction heat transfer is defined as follows:
equipment...the
temperature Where Q = Heat (W)
K = Thermal Conductivity (W/mK)
difference is
A = Area (m 2)
proportional to the t = Thickness (m)
T2, T1 are the hot and cold temperatures
heat flux; inversely ΔT = T2—T1
proportional to We can rewrite the equation:
conductivity; and
directly
So this tells us that the temperature difference is proportional to the heat flux (Q/A) in
proportional to W/m 2or more commonly W/cm 2; it is inversely proportional to K conductivity; and directly
proportional to t thickness. It is interesting to note the heat flux parameter which indicates that
thickness...the the more localized the heat source the greater the temperature drop will be across the
thermal interface. To demonstrate the result of this, below is a table which provides
more localized the temperature difference values under different conditions.
heat source the
Heat Flux K t t ΔT
greater the
(W/cm2) (W/mK) (mm) (in) (Deg C)
temperature drop 15.5 6 1 0.039 pad 25.83333 100 W
15.5 6 0.5 0.020 pad 12.91667 2.54 cm x 2.54 cm IC
will be across the 15.5 6 0.05 0.002 grease 1.291667 (1 in x 1 in IC)
62 6 1 0.039 pad 103.3333 100 W
thermal interface.” 62 6 0.5 0.020 pad 51.66667 1.27 cm x 1.27 cm IC
62 6 0.05 0.002 grease 5.166667 (0.5 in x 0.5 in IC)
4.65 6 1 0.039 pad 7.75 30 W
4.65 6 0.5 0.020 pad 3.875 2.54 cm x 2.54 cm IC
4.65 6 0.05 0.002 grease 0.3875 (1 in x 1 in IC)
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3. Page 3 TDMG Newsletter July 11th, 2011 Volume 2, Issue 1
Fi nit e E lem e nt S tr e ss & B uck li ng A na lys is f or a S hel vi ng R ac k S y st em
Finite element stress solutions implemented prior
analysis is a very useful to building any prototypes, “Finite element stress
tool to evaluate the thereby increasing the
strength of any structure. In l ik el ih oo d of d e sig n analysis is a very
this case, a rack system success.
was considered from both a useful tool to evaluate
The structure was
stress and buckling point of
discretized using shell and the strength of any
view. The interesting thing
beam finite elements. The
about using finite element structure…”
loading is applied as per
analysis (or simulation) is
specification and the
that problem areas can be
resulting stresses,
readily identified and will not occur during the life
deflections, and buckling
of the system.
loads are determined by
analysis. The safety factors Should you have any
can then be established questions regarding this
locally to make sure that type of analysis do not
the structure is safe under hesitate to call us or e-mail
the prescribed loading. us.
The buckling loads can
also be investigated to
ensure that such an event
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Phone: 514-381-9115
E-mail: info@tdmginc.com
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