Shear-Strained Poetry

In the Heat Transfer Lab in Em. E.
Six students now write poetry.
Boiling and Electronics
Great verse and some phonics
And some day they'll get a degree.
—Avram Bar-Cohen


Submerged - A Condensation

Electronics cooled by immersion and boiling
Requires vapor-to-liquid converting.
With condenser submerged
The aim can far better be served
Since augmentation results from bubble-pumping.
—Avram Bar-Cohen
 
 Polymer Heat Transfer Poem
I was under the impression
Polymers can carry only little heat by conduction
Weak Van der Waal forces restrict heat transfer
Causing polymers to disappear into vapor at moderate temperature
Then I learnt in distant lands there exists this magic filler
That turns dull plastics into a thriller
Short carbon fiber is the name
That turns the polymer heat transfer game
These fibers can form a connection
Increasing heat transfer across polymer by conduction
We want to add these fibers in little
Lest they will make polymer’s energy intense but brittle
Now the tables are turned
Heat sink mass is reduced
CTE of plastic and silicon match well
Low energy is needed from well to Dell
—Raj Bahadur

Thermo-Optical World as I See it
Alone in a boat in the middle of pacific ocean
Confusing myself and going to wrong direction
Physics of polymer Bragg gratings
Thermo-optical issues in polymer Bragg gratings
Why I’m doing this ?
Only continuous self-questions without answers
Distracting myself without focusing to physics
Losing lots of time, confusion, and even depression
Embarrassment with critical mistake
Finally I see better
What I should do, why I’m doing this.
BGs as a key component for photonics system
Broad applications such as filtering, coupling, wavelength stabilization
In spite of polymer BGs in research level
Possibly good alternative to glass BGs in near future
Environment and self heating induced by light energy absorption may cause Temperature, grating period change, stress in polymer BGs
Resulting in degradation of optical performance
Such as wavelength shift and dispersion
Clear understanding thermo-optical effect in polymer BGs
Possibly enable us to have better thermo-optical design criteria of polymer BGs
Energy variation based on coupled wave theory in polymer BGs
Usage of Transfer Matrix Methods
Clarifying non-uniform temperature and grating periods effect
Despite physically challenging issues ahead
I promise myself to keep focusing on my own work
Cause I know my old and painful mistake
—Kyoung Joon Kim

Thermoelectric μ-Cooler
With non-uniform heat flux
Hotspots on chip are formed,
In order to remove hotspots
Tiny TE coolers are tried.
With Peltier cooling effect
The hotspots get colder,
With Joule heating effect
The hotspots become hotter.
How to choose system geometry
To make Peltier cooling maximized?
What electrical design to apply
To have Joule heating minimized?
Staring with one cooler configuration
We made hotspots 4 oC cooling,
Next step for multiple coolers
Can we find anything exciting?
 —By Peng Wang

Troublesome Hot Spot

Photons and phonons, what do they all mean,
Doping concentration, heat transportation,
And everything in between,

I seek Peltier, his effect will display,
How two different metals may drive heat away,
At their junction cooling occurs, so I’ve heard,
The hot spot knows its days are numbered,

Will the newcomer, superlattice,
Who arrives from the abyss,
Vanquish this hot spot, or miss?

Only ANSYS will tell,
So I get online help,
Reading for days, oh what a load,
Until the day I may finally, decipher Peng’s code,

Nsel, asel, and vsel, can’t forget sbctran,
Seebeck and material properties in hand,
Thermal conductivity, electric resistivity,
They fit the plan,
 
Current runs loops to get the cooling value,
Alas, the poster is made so everyone can view.

/eof

-Viatcheslav Litvinovitch

Two Phases
Two phases are better than one;
for cooling things, it's second to none.
Condensation is the way
high temperatures are kept at bay,
and yet I wonder why the snow
can't be used to keep temperatures low.
What is it about a liquid spray
which is mixed with a gas array
that such cooling can be done,
and contribute to all this fun?
—Gary Solbreken
 
Evaporative Solution
"All this stuff is getting so hot!
What can I do to make it stop?"
"Sit down and have a listen my friend,
I can put all your problems to an end."
"I don't believe it - what can you do,
To make this heat vanish without a clue?"
"The solution is simple, as you will see,
A mixture of gas and liquid is all that you need.
Mixed in a ratio to give an annular regime,
The thin liquid film doen more than it may seem.
The heat travels through the film by conduction
To the interface, from the source of its production.
Now this is the part which is really great,
The liquid at the interface then evaporates.
Of course, evaporation depends upon the state
Of the interface, which the gas and liquid make.
When the saturation pressure is lower,
Evaporation will occur much slower.
Also a consideration is the heating configuration,
With symmetric distribution the ideal situation."
"Thank you for telling me about this cooling operation,
This phase-change cooling at temperatures below nucleation."
—Gary Solbreken

Oh, Madam Boiling Curve

Oh Madam Boiling Curve
goddess of the ebullient world
you know all there is to know
about your boiling two-phase flow

at you I long to make a pass
your tempting curves, my flux- or temp-controlled caress
but though I boldly start the trek
I dare not pass your CHF

—Karl Geisler

Journey of the Joules

Oh Heatsink bold,
finned cuboid creature.
What mysteries could you hold,
so devoid of feature.
You are but a bit of metal,
swimming in the sea.
Joules flow through your flowery petal
on their way to entropy.

Joules, what path do you travel
on your march to low potentiality.
You rose torrid from silicon deep below,
forsaken heat of the base
must now the way of the gradient go.

Joules through aluminum lattice came wriggling
til air particles Joules set jiggling,
exhorted by might of pressure and flow,
still more Joules must go.

Now Joules, what legions your promenade
down corridors of energy
between walls only you have made,
speak to us your design apogee.

—Maurice Holahan

Forget that Boiling and Become a Master
(Why waste all this work you boiling-snob jerk?)

I began as a lad, Physics Bachelor's in hand,
Looking for something new.
Came to the U, saw what boiling could do,
And that's when I fell in love.

Natural convection swept me aside,
ABC's class, a case study gone awry.
And on that fateful day my true love went away,
Since then I've never quite felt the same.

Interesting? Well yes, electronics cooling, nonetheless
I was up to the task, though my patience died fast,
When the boss man proposed this to me:
"Let's write a paper," he said with a smiley,
"Let's write a paper and go to Hawaii!"

Oh, woe is me, it is never ending,
but at least I'll have fun in the sun.
This made me feel better, promises of great weather
and plenty of scuba-diving.
But the true blessing from this disaster
is that I'll be back to boiling much faster,
if I wrap it all up by becoming a Master.

—Karl J. Geisler

To My Dear Electronic Packaging
-A Senseless Love Sonnet

Oh, electronic packaging, oh, pure dice,
I love you, hate you all the same.
You are a chip, a time dependence,
You are a Weibull distribution, so humid and so clear.

For you, I would creep and even melt.
Oh, tell me that you love me, and I'll crash.
My love for you is like a microchip
That shears off adhered die.

It's as glued as a conduction,
It's as hot as a peel stress.
Oh, how restlessly I love you,
My dear plastic packaging, my darling pure dice,

Tell me, tell me that you love me,
And I'll ... graduate.

—Vadim Gektin

An Epic Limerick

A student from Kansas you see
Sought to study dT/dt
Puzzled, but inspired
When he was required
To write stanzas of poetry.

Cavitation was chosen to be
The topic studied by me
The first quarter ended
With knowledge extended
In ways one hundred and three.

My advisor, they called him Bar-Cohen
Cross the whole world he was well known
His quick repartee
As we came to see
Was occasionally mixed with a poem.

No topic he failed to elucidate
Exemplify, expand, and illuminate
His fame not acquired
By concepts inspired
But by the technical poets he did create.

Just think of all of the time
That would be saved, both yours and mine
If each journal and transaction
Were subjected to compaction
By making each paragraph rhyme.

Why stop at technical rhyme?
Other art forms are certainly prime
To give lasting impressions
Of obscure expressions
We could do them in pantomime.

—Evan Graham

AWAY WITH THE LEAVES

Students' dearest wish:
Summer's stifling heat stolen
By Winter's chill breath.

—Jon Green

Stopping by the Web on a Snowy Evening...(apologies to Robert Frost)

Whose poems these are, I think I know.
They dwell in virtual village, though.
They will not see me stopping here.
To read their poetry and prose.

My little mouse must think it queer
Clicking on poems by engineers
Across the city at the UofM
So far away and yet so near.

I thought it must be a mistake.
What path did that web brower take?
I searched for "heat sinks"
And found MEs with the soul of Blake.

Your poems are charming and endearing.
Dr. Bar-Cohen's writing goal is quite cheering
But best you stick to engineering.
But best you stick to engineering.

—C. R. Gurstelle

Two Phase Flow What Do We Know

Two phase flow
What do we know
Plus or minus 50
So how do we know what anybody meant

Two phase flow
What do we know
Pressure drop correlations
Proved by experiment, not to be revelations

Two phase flow
What do we know
Never leave the parametric range
Or else your results appear very strange

Two phase flow
What do we know
What goes on at the interface
Is a hopeless problem for the human race

Two phase flow
What do we know
Trying to shift from stratified to elongated bubble
Can cause a whole lot of trouble

Two phase flow
What do we know
The equation works great for this configuration
But what about the slightest perturbation

Two phase flow
What do we know
That equation's physical representation seems realistic
Oh, about its solutions don't be opportunistic

Two phase flow
What do we know
We can all work towards a unified formulation
But should never expect any feelings of elation

—Marc Hodes

A Cool Computer

Computers are getting bigger and bigger and people are starting to say
How do we make this heat go away?

Some say that a mammoth fan is the way to go.
But everyone knows that blowing harder
won't always make your cooling wishes so.

One must be clever and wise.
If an effective cooling scheme he is to devise.

Through the careful use of analytical, numerical, and experimental
analysis
We hope to avoid thermally induced system paralysis.

For the first pass analytical is the way to go.
It saves time, which is precious as we all know.

Now its on to numerical festivities.
One must model the problem precisely with little suggestivity.

Its a task for some,
But a joy for those who think number crunching is number one.

Hopefully, the solution will show
That the analytical method was the way to go.

Finally, the check of all checks
This is were you really lay out your neck.

The experimental results better agree,
Or the other two exercises are worthless as can be.

Careful now, and a word to the wise
Be sure to include structural analysis
or you solution will crumble before your eyes.

—Karl Hokanson

An Ode to Little Heaters

We told the folks in St. Peter
A buried resistor is just a small heater
That when operating
Would meet a power rating
Given by our experimental meter.

—Zane Johnson

Buried Resistors

When resistors are buried in boards
Their temperatures increase by the hoards
Core spreading and fins
give a model that wins
The resistance is right my dear lords.

—Zane Johnson

A Poem About Passive Immersion

This poem is about passive immersion
for 2 years my full time diversion
studied many thick tomes
wrote a couple of poems
and wrote my paper in many a version

For multi-chip modules with plenty of heat
there's a phenomena that is really quite neat
use immersion that's passive
systems small mid or massive
will have a packaging solution complete

The fluid travels by natural convection
both in the upward and downward direction
recirculation is internal
with no pumps so infernal
yet the chips are cooled to perfection

At high heat flux the chips they dispense
small bubbles with heat you can't sense
they rise up to the fin
not to fat or too thin
so the bubbles are sure to condense

Of Critical Heat Flux we are quite wary
therefore subcooling and pressure may vary
to avoid overshoot
some dissolved gas will suit
to make any concerns unnecessary

—David Kitching

A Tribute to Poem-Writing Engineers

I clicked, I saw, said "Oh Dears!
Poems written by engineers!"
Though some may think it wrong,
it's fine to trade maths for a song.

Cause it's fine for us to abuse,
some of the left-brain left unused.
And show those who think us bore,
that we know more than just techno lore.

—Eugene Lim

Heat Transfer Poems

There once was a man from Nantucket
Who had to move heat by the bucket
He said with a grin, I will use a fin,
and if that doesn't work I will shuck it.


In days of old, engineers were bold
and statistics was not invented
they'd write their conclusions
often filled with illusions
and walk away contented.

—Andrew McNeil

Passive Cooling of Electronic Equipment THE REAL STORY

To this U I came
hoping for fame
with nothing but dreams.
I had to know a man (advisor)
by whom I was told about this idea
air carries heat by itself
as it warms up it goes up the shelf.

I said ``I see''
he replied ``This is linked to high technology''
however the work before me
did not cover well the entire range of b
so off I went to correct this irony.

Equipped with ignorance, I started inventing a theory
roughness, porous flow, all the same to me
one failure after another
learning was the obvious remedy
and after a few lessons at the UMHTD
ideas began to flow and solutions as easily.

From computation to experimentation
with some theory in between for the presentation
the more I knew the more difficult the simple became
However with these tools, I began to build the frame
I sorted out the useful from the useless claim
with all its ups and downs today i present to you
the saga of my melody.

—Khedher Mellah

Microelectronics Packaging U of Mn - A Rap

The task of microelectronics packaging and cooling - can oftentimes be quite gruelling.

Not only does the issue of heat transfer become a test - but the problem of thermal stress can creep up and become a pest.

So, if you are fatigued and in a pinch - but have the cash and are willing to invest - contact the U of Mn packaging staff and we'll take care of the rest.

Although our analyses don't come cheap - the results you'll get can't be beat.

—Devin Mix

Intro to UofM (Smells like keen spirit)

Engineering Degrees in my holster
and a 50% assistantship to bolster
TME at Minn gave me a glim
where I found "you're so hot, you're so SLIM".
Hop onto the bagel roller-coaster!

—Sridhar Narasimhan

Desire

A Japanese guy graduated from Physics
once became pipe-man in computer firm
now wishes to be a boiler.

Avoided the first hurdle, English
kicked away boiling heat transfer
next target was the submerged condenser
formidable giant.

He hoped to take a long time in overthrowing it
to be able to enjoy life here.

—Ted Ogata

Bar-Cohen
(adapted from E.A. Poe's, "The Raven")

Once upon a weeknight dreary, while I studied, bleak and bleary,
Pouring over Hetsroni's volumes of two-phase lore--
Still I worked, splitting atoms, and energy source soon abandoned,
By a public beguiled and banded, banded by the monster Gore.
"ME Plan B," I muttered, when a phone call froze me to the core--
Quoth Bar-Cohen, "You need more."

Ah, distinctly I remember, it was in the Twin Cities September,
When first my soul was rendered to the Taitel and Dukler score.
Yet to Bergles it seemed so clear, that regimes define when dryout is near,
But for me I had my own fears, whether we could convince the EPRI lords.
Convince myself that regimes are more than stock and store.
Merely this and a little more.

Deep in the database stumbling, long I searched for flows a bubbling, slugging,
Chugging, churning flows where only annular flows were found before.
Following the steps of Hodes, better tools for boiling crisis,
Could this be a Master's thesis, I saw my sweat upon the floor;
But the data confirmed our hopes, to end this mystery explored--
Quoth Bar-Cohen, "There's still more,"

And the test loop, pieces missing, still is sitting, still is sitting,
In ME 458, most of which is on the floor.
But in time with a little dreaming, water and air will soon be streaming,
And the tube with photons teeming, will measure the vapor core.
And from that tube we hope the flow stays off the floor;
And then it ends--nevermore!

—David Pribyl

My Heart Doth Wax & Wane With Q

O Love, began with your picture in the Daily , fist in air, I knew you were for me, you were screaming ``Nazi Beware!!'' Black leggings, black shoes, black dress, oh, and black hair.

My little living dead cherub enrolled in Poly Sci, CLA, to tell you of my love, for me, there is only one way. By the modes of heat transfer, my message they will convey.

Radiation--what I feel over distance; thru air and across land. I in the crowd, and you on the mall with microphone in hand, my heart tis throbbing as you scream, ``Homophobics be Damned!''

Convection--what I feel when I'm caught in your wake. I rush the police barrier when you march for other's sake, and swoon as you pass with sign, ``Politicians are on the Take.''

Conduction--what I feel when tear gas burns my eyes. I stand with you when they suppress your exposure of their lies. Clubbed by the cops, I call you midst the chaos and cries.

O Love, my feelings I exclaim, but yours I haven't a clue. When you get out on bail, return love; this you must do, for my heart must know, it doth wax & wane with Q.

—Michael Richards

Memoir

A long time ago
In the city of Bombay
There lived an engineer
His name was Abhay.

He thought he was a master
At calculating heat transfer
Until he tried an estimation
Of the peak heat flux in nucleation.

He read the tomes and surveyed the lit
And even got an MS degree
But he never did get a single equation
For heat flux in terms of delta T.

But now he wants to get a Ph.D
With a new advisor and university
And before he is old and worn out
He hopes to model burnout.

—Abhay Watwe

Parametric Whims of CHF

The increasing chip power dissipation,
in many a future electronic application,
requires some extraordinary measures,
to control the soaring component temperatures.

In order to keep these hot chips cool,
we chose to immerse them in a fluorocarbon pool.
The hot chips make the liquid boil.
and the bubbles cool the chip with their turmoil.

But at sufficiently high chip power,
there is just too much vapor.
For discrete bubbles there is no room.
So they merge into a vapor mushroom.

Then parts of the chip become too hot.
Tis we believe because of a dry spot.
If re-wetting this spot becomes infeasible,
we call the chip heat flux critical.

On a hunch, we increased system pressure.
The bubbles, they shrank in diameter.
Vapor mushroom formation was delayed.
By golly!! CHF was raised.

Then we lowered the temperature bulk.
Once again the bubbles began to sulk.
Condensation made the mushroom less bulkier.
The subcooling increase in CHF was linear.

Emboldened, we combined subcooling and pressure,
hoping that CHF would be even greater.
But the two effects were not additive,
at higher pressures subcooling was less effective.

So we proposed a composite equation.
In order to predict the CHF variation.
Under the influence of many a parameter,
like thickness, liquid subcooling and pressure.

—Abhay Watwe