of the "rational heat engine"
Rudolf Christian Karl Diesel
was born in Paris, France, on March 18, 1858, the
son of German immigrants. As a young boy he spent
many hours in the Paris Museum of Arts and
Crafts, where he often made drawings of the
various machines on display. After the family
moved to London upon outbreak of the
Franco-Prussian War in 1870, Diesel began
frequenting the Science Museum there. He was
subsequently sent to Augsburg, Germany, to live
with an uncle, a professor of mathematics at the
Augsburg trade school. It was in Augsburg that he
first saw a pump which created heat by
compression of air, and it was this pump that
would eventually lead to the engine which now
bears his name.
In 1875 Diesel began attending
lectures at Munich Technical University, and
subsequently graduated with the most brilliant
record in the university's history to that time.
One of the lectures he attended was held by Carl
von Linde, whose research in thermodynamics had
led to the invention of refrigeration techniques.
After graduating Diesel began working at Linde's
refrigeration company. In 1880 he returned to
Paris to assist in the construction of a
refrigeration plant, and then became manager of
that plant. He would continue to work for Linde
until about 1890.
During the course of Diesel's university
studies and early working career he determined
that existing engines were inefficient and became
resolved to build a better one. He initially
worked on an expansion engine that used ammonia
as the working fluid, but the engine exploded
during a test and left Diesel seriously injured.
He then decided to use the heat generated by
compressing air to ignite a fuel mixture in the
cylinder, and in 1885 he set up a shop-laboratory
in Paris to perfect the concept. He received his
first patent in 1892, and his second in 1893.
Also in 1893, he published a paper about his
engine, entitled The Theory and Design of a
Rational Heat Engine.
With help from Linde, Diesel
was able to secure financing from two German
companies to develop his engine, and he began
working in Augsburg in 1893. His first successful
engine -- a single cylinder, four stroke model
that made 25 horsepower -- was built in 1897, and
demonstrated at a Munich exhibition the following
year. Diesel began selling licenses to build his
engine, and soon became a millionaire.
What made (and continues to make) Diesel's
engine different was that, unlike other internal
combustion engines, it requires no spark plug to
ignite the fuel. In "traditional"
engines, the fuel is combined with the air first,
the air-fuel mixture is then compressed, and then
a spark is introduced to ignite the fuel. But in
Diesel's engine, the fuel is not introduced until
the air is already compressed and hot, and it is
the hot air that causes the fuel to ignite.
While Diesel's engine enjoyed immediate
success, it did have its problems. The tremendous
pressures under which the engine operated meant
that any flaw in the materials from which it was
made could easily lead to failure. In addition,
Diesel always insisted that his engines be built
to his original specifications and was habitually
slow about incorporating improvements into the
basic design. To make matters worse, Diesel's was
not the first compression-ignition engine to be
tested, and some of his patents were contested.
Although Diesel ultimately won all of the patent
battles and therefore the right to have his name
permanently affiliated with the
compression-ignition engine, the battles left a
toll on his mental health, which many have said
was already questionable.
On September 29, 1913, Diesel disappeared
during a trip across the North Sea from Antwerp,
Belgium, to Harwich, England, aboard the mail
steamer Dresden. His body was found in
the water a few days later, and it is believed by
most that he committed suicide by jumping off the
ship. His book, The Genesis of Diesel Motors,
was published shortly before his death.
The Engines of Our Ingenuity www.uh.edu/engines/epi1435.htm
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