Evolution of the Stirling Engine
The Dr Revered Stirling invented the Stirling Engine in 1880 in Stirling, Scotland. Over the next 100 years it found applications in space, medical, transport and burning methane from waste sites. Minor changes happened, but nothing new from a design prospective.
Then in the 1980s the microprocessor came on the market and added precise control to the Stirling Engine (i.e. 0.001 per degree steps). The Stirling Engine is a thermal engine and therefore about 80 to 90% efficient. Also the basic engine consists of 2 cylinders with a heat exchanger in the middle. So by heating one cylinder, the other one goes cold because of the heat exchanger in the middle. Kockums Marine AB, Malmo, Sweden launched a submarine in 1978 with 1000 hours on Stirling power in its first year.
This was a big step forward with multiple cylinders and other technology. This engine was then used in submarines throughout the Western World. Also during this time NASA used it for space experiments, since the engine is almost silent when running. At this time a US company was formed to build the US Stirling Engines, with the name Stirling Engine Inc and claimed intellectual property rights, when the copyright had expired in 1930. This is something that US organisations seem to do under the threat of legal action.
In July 1992 the magazine Electronics World + Wireless World had an article titled “Electricity out of Magnetism” what Dr Harold Aspden and John Scott Strachan had produced was a solid state Stirling Engine. This made me declare that this form of Stirling Engine would be more environmentally friendly than any of the proposed fuel cells and more efficient. This caused a lot of upset with the fuel cell researchers. Read the rest of this entry »
From 2.5L to 3.2L: The Evolution of the Porsche Boxster
As a car drives by you, the first thing you notice that will surely make your head turn, is the sleek shiny exterior that can reflect the sun straight into your eyes. Some cars that have nice paint jobs can already make the heads of people turn, but with a Porsche Boxster, people know that a shiny waxed paint job is not the only thing that it can offer. In fact, a Porsche Boxster can make heads turn before running past your line of sight. This is what Porsche have done best with this model since its started its production in 1996.
Initially there were six versions of Porsche Boxsters, with the Porsche 986 as first in a whole line of Boxsters. This first Boxster had a 2.5-litre flat six cylinder engine, while the S variant which was released in 2000 had a 3.2-litre capacity, while the base model also received an 2.7-litre upgrade. In 2003 they upgraded not just the engine, but the overall styling of the body for maximum aerodynamics as well. It was in 2005 that they released the 987, which is of course more powerful than the 986, and had a body that resembled the Porsche Carrera GT. By 2007, Porsche decided to increase the engine output, wherein both Boxster models were able to receive the engines that the Porsche Cayman had. Then finally, in 2009, the Boxster received a new facelift, as well as internal changes that greatly increased the engine output and overall performance.
It is good to know that Porsche is one of the few car manufacturers that value the increase of speed whenever they do upgrades, which is very evident with their ever-rising top speeds. From the 149 miles per hour of the 2.5-litre 986 to the now 165 miles per hour top speed of the S 550 variant, that only a handful of cars can compete with. Read the rest of this entry »