Search results
Results From The WOW.Com Content Network
The shape of the combustion chamber, intake ports and exhaust ports are key to achieving efficient combustion and maximising power output. Cylinder heads are often designed to achieve a certain "swirl" pattern (rotational component to the gas flow) and turbulence , which improves the mixing and increases the flow rate of gasses.
Turbulence in the combustion chamber due to this squish helps with air-fuel mixing, cylinder wall heat transfer, thermal efficiency, and overall engine performance. Heat transfer is aided when the combustion gasses swirl around and heat the cylinder wall, allowing the cooling system to work more efficiently. [3]
The swirler establishes a local low pressure zone that forces some of the combustion products to recirculate, creating the high turbulence. [11] However, the higher the turbulence, the higher the pressure loss will be for the combustor, so the dome and swirler must be carefully designed so as not to generate more turbulence than is needed to ...
Side valve engine with Ricardo's "Turbulent Head" In 1919 Ricardo was studying the phenomena affecting the combustion within the petrol engine and the diesel engine. He realised that turbulence within the combustion chamber increased flame speed, and that he could achieve this by offsetting the cylinder head. He also realised that making the ...
A Heron cylinder head, or simply Heron head, is a design for the combustion chambers of the cylinder head on an internal combustion piston engine, named for engine designer S. D. Heron. The head is machined flat, with recesses only for inlet and exhaust valves, spark plugs, injectors and so on.
A hemispherical head ("hemi-head") gives an efficient combustion chamber with minimal heat loss to the head, and allows for two large valves.However, a hemi-head usually allows no more than two valves per cylinder due to the difficulty in arranging the valve gear for four valves at diverging angles, and these large valves are necessarily heavier than those in a multi-valve engine of similar ...
Small quantities of compressor bleed air are also used to cool the shaft, turbine shrouds, etc. Some air is also used to keep the temperature of the combustion chamber walls below critical. This is done using primary and secondary airholes which allow a thin layer of air to cover the inner walls of the chamber preventing excessive heating.
In a real gas turbine, mechanical energy is changed irreversibly (due to internal friction and turbulence) into pressure and thermal energy when the gas is compressed (in either a centrifugal or axial compressor). Heat is added in the combustion chamber and the specific volume of the gas increases, accompanied by a slight loss in pressure ...