Piston engines

An important appHcation of MMCs in the automotive area is in diesel piston crowns (53). This appHcation involves incorporation of short fibers of alumina or alumina—siHca in the crown of the piston. The conventional diesel engine piston has an Al—Si casting alloy with a crown made of a nickel cast iron. The replacement of the nickel cast iron by aluminum matrix composite results in a lighter, more abrasion resistant, and cheaper product. Another appHcation in the automotive sector involves the use of carbon fiber and alumina particles in an aluminum matrix for use as cylinder liners in the Prelude model of Honda Motor Co. 

The largest application of polycyanurates is in circuit hoards. Their transparency to microwave and radar energy makes them useful for manufacturing the housing of radar antennas of military and reconnaissance planes. Their impact resistance makes them ideal for aircraft structures and engine pistons. ... 

Cross section of the Cl engine piston with a typical quiescent-bowl shape and a centrally located high-pressure fuel irtjector. 

Aqueous and organic liquids, powders, polymers, papers, and fabricated solids can all be analyzed directly by XRF. The method is nondestructive, so unless dilution is required, the original sample is returned to the submitter. Although the method can be applied to the analysis of materials ranging in size from milligram quantities to bulk parts such as engine pistons, a minimum of 5 grams of sample is usually required for accurate quantitative analysis. 

The compression of the gases is carried out in this machine by two pistons fixed at an angle of ninety degrees to one another and connected by a cam. The engine piston is put into motion by the expansion of a gas this then displaces the actual piston via the cam the latter has a path of 19.9 cm and the compression ratio reaches 9.8. The duration of the compression is adjusted to a value between 20 and 80 ms by changing the pressure of the driving gas. 

The principle of isotopic wear studies is to label the material to be worn and monitor the material loss by radiation measurement. A typical example is studying car engine piston rings labeled, e.g., by neutron activation and measuring the accumulation of radioactivity in the lubricant oil. The measured count rates can be converted to mass by the appropriate calibration. Another example from the vehicle industry is to study the wearing of car tyres. 

Small quantities of phosphides can act as crystallisation nuclei for components of alloys. High-strength materials for engine pistons are obtained by adding 0.01-0.03% P to certain Al/Si/Cu alloys. The AlP, which is formed, provides crystallisation nuclei for the growth of Si crystals of suitable size, which increase wear resistance. 

Particles and both short and continuous AI2O3 fibers have been used to reinforce tduminum alloys. A short type of AI2O3 fiber has been used to reinforce diesel-engine pistons [73]. 

At the root of the classical thermodynamics of engines is the fact that work is an important and measurable quantity. However, work, while measurable, is rarely predictable. The work performed by a gas expanding in an engine piston can depend on pressure, volume, temperature, speed of the piston motion, frictional forces, and other factors in complex ways that are not fully understood. 

Cavitation damage (sometimes referred to as cavitation corrosion or cavitation erosion) is a form of localized corrosion combined with mechanical damage that occurs in turbulent or rapidly moving liquids and takes the form of areas or patches of pitted or roughened surface. Cavitation has been defined as the deterioration of a surface caused by the sudden formation and collapse of bubbles in a liquid. It has been similarly defined as the localized attack that results from the collapse of voids or cavities due to turbulence in a liquid at a metal surface. Cavitation also occurs in areas of high vibration such as on engine pistons and piston liners (Fig. 6.43). 

Cavitation damage of a diesei engine piston iiner on the return stroke. (Courtesy of Defence R D Canada-Atiantic)... 

Figure 1 shows a typical gasoline engine piston/liner interface. The most simple and commonly used tool to simulate this lubrication system is by one-dimensional Reynolds equations. Although there are some 2D/3D tools available, they are generally either too complicated or lack the required accin-acy. 

Internal combustion engine pistons, blocks manifolds,... 

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