There have been a number of articles in the press on the benefits of a flywheel-based hybrid system for motor racing - indeed, Porsche has been racing a flywheel hybrid system in selected GT races. This is based on the same technology that Williams had begun to develop for its Formula One car for the 2009 season, but which didn’t race. In this system, the flywheel and alternator are combined, so the system is a mix of the benefits of flywheel energy storage and the well-known technology of the electric motor. Read more…
Archive for December, 2010
Le Mans Prototype flywheel hybrid
Thursday, December 16th, 2010Valve seats, cool
Thursday, December 16th, 2010
This is a follow-up to my earlier articles on cylinder head loading. Earlier, I described what is known as one of the most critical failure modes, Thermo Mechanical Fatigue, or TMF. In those articles the three main load cases were mentioned - assembly loads, (peak) firing pressure load and thermal load. For thermal load, further insight was given into the design of the cylinder head cooling jacket. The conclusion was that the jacket is mainly derived from the rest of the structural design, for example cylinder head bolt locations, inlet and exhaust ports and valve guides and seats. Read more…
Nitromethane - rocket fuel or what?
Thursday, December 16th, 2010
A major factor in selecting any fuel for high-performance work is the ratio of the products of the reaction with the oxygen in the air to that of the reactants. In a liquid-fuelled space rocket, for instance, 1000 gallons of liquid oxygen will react with about 2000 of liquid hydrogen to create an exhaust gas many times the initial volume. This increase in volume escaping from beneath creates the thrust, which subsequently propels the projectile forward. Read more…
Composite fasteners, part 2
Thursday, December 16th, 2010
In the previous article on fasteners, we looked at a very clever design of threaded fastener that used a composite shank with the threaded portions of the component still produced in high-strength metallic materials. Not only do these fasteners use a polymer-matrix composite shank but, being made of multiple parts, they are, in the broader sense of the definition, a composite component.
A European company has developed a new form of composite fastener that is a pure polymer-matrix Read more…
Welding Inconel
Thursday, December 16th, 2010
As long as there is the pursuit for extra power there will always have to be a commitment to using more advanced and exotic materials. Exhaust design is no exception, and many exhaust systems - both classic and contemporary - provide us not only with engineering artwork but a technical challenge.
One criterion expected of performance exhausts is their need to work at sustained elevated working temperatures, which has necessitated the use of more Read more…
The gear change
Thursday, December 16th, 2010
Like millions of other followers of Formula One, I look forward each year to sitting in front of the TV and watching both practice and race of every single Grand Prix throughout the season. Also like many others, I have done this for probably the best part of 30 years, for as long as the sport has been covered by prime-time TV.
I always enjoy some of the on-board coverage looking over the driver’s shoulder. In particular, I marvel at the way that 750-plus bhp can be tamed by our heroes with Read more…
The heat is on
Thursday, December 16th, 2010
One of the most difficult tasks for an experienced dyno engineer is to measure the amount of heat rejected to the engine coolant. On the face of it, fitting thermocouples - one in the engine water going in and another as it comes out and then measuring the coolant flow rate, would seem a simple enough task. But when we analyse the accuracy of the instruments used, the level of uncertainty calls for a more considered approach. The problem, as you probably appreciate by now, is not the accuracy of any particular flow meter to be used but Read more…
Methods of fitting heavy metal to counterweights, part 2
Thursday, December 16th, 2010
In the previous article on the subject of adding tungsten counterweighting to crankshafts, we looked at one of the more widely adopted methods where cylinders of tungsten alloy are pressed or shrunk into specifically machined bores in the counterweights. The conclusion that many crankshaft manufacturers and design engineers have come to is that this is a reasonably effective method of adding tungsten while affording generous safety factors against failure. It is also simple from a practical point of view. Read more…
Location of con rod caps, part 2
Thursday, December 16th, 2010
In the previous article on the subject of maintaining the accurate locations of the two parts of a split con rod design, we looked at dowel pins and ring dowels, and the relative merits of the two methods.
The subject of joint shear stiffness was raised, and it was noted that the ring dowel, having a greater cross-sectional area, provides more stiffness to the joint. A stiffer joint is more stable and less likely to suffer from joint face fretting wear. While the con rod bolt may not Read more…
Silver plating of fasteners
Thursday, December 16th, 2010
The matter of selecting the correct material for fasteners is an important one. The design engineer or engine development specialist has to be sure that the material is strong enough to resist the applied loads and have the fatigue resistance to continue in its role between engine rebuilds. There are a huge number of materials offered by manufacturers of fasteners depending on the application, service loads, environment and so on.
The job of those working with internal combustion Read more…
