Picture a world where Rudolf Diesel never existed. Shipping vessels that transport goods and people to facilitate trade between distant parts of the globe wouldn't be as massive or as efficient. The world's militaries and political power structures wouldn't have the tanks and trucks they do today. Steam locomotives may even still be in use. Diesel engines have influenced our lives in more ways than we realize and, the truth is, we would be in a drastically different place if not for them. That's why Diesel Power has decided to shed a little light on this important man and his engine that has been hidden from popular history.
| 10 Things You Didnt Know About Diesel rudolf Diesel
1. Diesel vs. Gasoline
In the 1890s, Rudolf Diesel's established competition were gasoline engines, which had 3:1 and 4:1 compression ratios. At the time, leading gasoline engine experts predicted increasing an engine's compression ratio would increase the frictional and mechanical losses at a greater rate than they could raise efficiency and power.
2. Diesel Used Water Injection
Diesel didn't invent water injection, but he did call for it to be used in his first engine designs. Water injection was first used in a Banki engine (invented by the man who created the carburetor) in 1894. This modification increased the compression ratio of gasoline-burning engines to a mind-blowing (at the time) 6.7:1. This important ratio was increased in the 1920s through the introduction of the gasoline additive tetra-ethyl lead. Today's gasoline engines have roughly a 10:1 compression ratio, while diesel engines run more than 16:1.
3. Diesel's Ideal Engine
Rudolf Diesel's original engine design called for a 52:1 compression ratio. This revolutionary path came directly from the French physicist Sadi Carnot, whose trailblazing ideas drove Diesel's engine (and mind) to the ragged edge of destruction. Diesel predicted that his engine's peak combustion temperatures would be 2,192 degrees (dropped to 1,472 degrees by using water injection). Diesel reasoned that by the time the piston got to the bottom of its stroke, the increase in cylinder volume would've theoretically caused the temperature to drop to 248 degrees. This combination was hypothetically good for 73 percent thermal efficiency. Diesel's design also eliminated the need for external water cooling.
| Rudolf Diesel's first operational prototype weighed 10,000 pounds and produced 20 hp.
4. Diesel's Engine Compromise
In practice, Diesel was not able to keep up with Carnot's perfect thermodynamic theories, but they put him on the right track. Even though Diesel's compromised engine only had a 13:1 compression ratio, it was enough to break him free of the fuel-limited ratios plaguing gasoline engines. He also accepted his engine would need water cooling. Another setback had to do with the high-pressure fuel injection system, which did not work as intended (it took 30 years before a system like this came into existence-in the interim diesels used air injection). By 1895, Diesel's test engines were producing 25 percent thermal efficiency.
5. Diesel's First Engine Ran on Gasoline
Benzin is the German word for gasoline, and ironically that is the first fuel (according to historian Lyle Cummins) to ever be put in a diesel engine. At the time, Diesel was in uncharted waters, and he wanted to prove many different things-one of them was automatic combustion (compression-ignition). His initial test engine proved this by creating an uncontrolled explosion, which nearly caused Rudolf Diesel's early death. Still, the reason for the high-compression engine was thermodynamic theory, not automatic combustion, which came along as an extra bonus.
6. Diesel Did Not Design His Engine To Run on Vegetable Oil
The belief that Diesel designed his engine to run on vegetable oil makes us feel warm and fuzzy, but it's not true according to Lyle Cummins. The vegetable oil myth probably came from the French Otto Company, a diesel-licensee which displayed an engine running on peanut oil at the 1900 Paris Exhibition. However, it can be argued that Diesel designed his engine to help regular working people, since he experienced the toil of labor at an early age and had Bohemian friends in Paris.
| Rudolf Diesel (left), Carl Buz, and Moritz Schroter pose for a photo at a moment when Diesel finally got recognition from some of his peers.
7. Diesel's Detractors
Today you would never hear an engineer bad-mouth Rudolf Diesel, but that wasn't always the case. Established engine builders of the time called his design crazy and nicknamed Diesel's engine the Paper Engine (because it looked good on paper, but they thought it would never become anything more). Once the engine finally started to catch on, American diesel engine builders fundamentally disagreed with Diesel on many technical points. For example, Edward Meier said, "While I have the highest opinion of Mr. Diesel's knowledge of thermodynamics, I do not consider him to have sufficient practical ability to build a wheelbarrow. His criticism of our first American engine was childish and absurd." The constant attacks wore on Rudolf Diesel. In 1913, he said, "The introduction [of a new idea] is a time of the fight against stupidity and jealousy, laziness and malice, secret resistance and open struggle, the terrible time of conflicts with humans, [and it's] a martyrdom also if you are successful.
8. Diesel Had a Utopian Vision
Rudolf Diesel battled manic depression and migraines his whole life. By 1903, he was rich but was losing control of his patents-and his mind. His doctors told him to take a break. During this rest, he managed to publish a book that was supposed to solve the social problems of the world associated with labor, capital, and industrialization. It was called Solidarism: The Natural Economic Freeing of Mankind. On the cover of this book were the words Love, Brotherliness, Charity, Peaceableness, Veracity, and Justice. Diesel tried to tackle people problems the same scientific way he dealt with engines. He felt that since workers owned their labor, they should have better contracts with their employers.
9. Diesel Invented High-Pressure Fuel Lines
Diesel's ideas were light-years ahead of his time. He often had to come up with practical solutions so that his theoretical ideas could be put to the test. One of these hurdles was containing highly pressurized fuel with an easy-to-assemble connection. Regular threaded fittings leaked, and the sealants that were available worked for a while, but eventually were dissolved by the fuel. His fix was to forge a conical taper on the fuel line end, and a matching seat on the other end. This wedge created a tight fit we still use today.
10. Pressure Volume Diagrams: The Rosetta Stone of All Engines
When diesel first started thinking of his engine, his mind didn't focus on pistons, specific fuel types, and crankshafts. Instead he was interested in diagrams- pressure-volume (P-V) diagrams to be more exact. Sadi Carnot's perfect theoretical engine made a square shape on a P-V diagram with its compression and expansion. Diesel's outline was more of a diamond leaning to its left. The fatter the diamond, the more efficient the engine.
