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Its combustion chamber was lined with a thin copper sheet supported by the corrugated steel wall of the chamber. Fuel flowed through the corrugations and absorbed heat very efficiently. This permitted more energetic fuels and higher chamber pressures, and is the basic plan used in all Russian engines since.
Common shapes for the combustion chamber are typically similar to one or more half-spheres (such as the hemi, pent-roof, wedge or kidney-shaped chambers). The older flathead engine design uses a "bathtub"-shaped combustion chamber, with an elongated shape that sits above both the piston and the valves (which are located beside the piston).
A countercurrent heat exchanger with forced cooling air does the job. The cylinder-walls should not heat up the air before compression, but also not cool down the gas at the combustion. A compromise is a wall temperature of 90 °C. The viscosity of the oil is optimized for just this temperature.
In the case of a CI engine, the fuel injector quickly injects fuel into the combustion chamber as a spray; the fuel ignites due to the high temperature. Power or working stroke: The pressure of the combustion gases pushes the piston downward, generating more kinetic energy than is required to compress the charge.
Since the heat of combustion of these elements is known, the heating value can be calculated using Dulong's Formula: HHV [kJ/g]= 33.87m C + 122.3(m H - m O ÷ 8) + 9.4m S where m C , m H , m O , m N , and m S are the contents of carbon, hydrogen, oxygen, nitrogen, and sulfur on any (wet, dry or ash free) basis, respectively.
Ceramic fibre is commonly used for the roof and wall of the furnace and is graded by its density and then its maximum temperature rating. For example, 8# 2,300 °F means 8 lb/ft 3 density with a maximum temperature rating of 2,300 °F. The actual service temperature rating for ceramic fiber is a bit lower than the maximum rated temperature.
The typical design is the "wet back", where the rear face of the combustion chamber is water-jacketed as a heating surface. The "dry back" variation has the rear of the combustion chamber as an open box, backed or surrounded by only a sheet-metal jacket. [4] [5] This simplifies construction, but also loses much efficiency. It is used for only ...
The Oldsmobile engine was very similar to the Buick engine, but not identical: it had larger wedge combustion chambers with flat-topped (rather than domed) pistons, six bolts rather than five per cylinder head, and slightly larger intake valves; the valves were actuated by shaft-mounted rocker arms like the Buick and Pontiac versions, but the ...