scholarly journals Innovative “Green” Tribological Solutions for Clean Small Engines

10.5772/55836 ◽  
2013 ◽  
Author(s):  
Xana Fernndez-Prez ◽  
Amaya Igartua ◽  
Roman Nevshupa ◽  
Patricio Zabala ◽  
Borja Zabala ◽  
...  
Keyword(s):  
Small Engines

Supercharged Aero Engines

1926 ◽  
Vol 30 (190) ◽  
pp. 615-618
Author(s):  
R. F. R. Pierce
Keyword(s):  
Sea Level ◽  
Good Design ◽  
Actual Increase ◽  
Standard Design ◽  
Automobile Engines ◽  
Aero Engines ◽  
Small Engines ◽  
Large Output ◽  
Horse Power

The main object of this paper is to show the importance of supercharging, the desirable results brought about by the process, and a consideration of the difficulties.Supercharging, as understood by aeronautic engineers, is the process whereby the output of an engine at sea level is maintained at altitudes. Forced induction, by means of a rotary blower, has however been tried on automobile engines. Only one maker, Mercedes, has so far incorporated this feature in the standard design. This practice has much to be said for it, as a small engine may be made to give a large output without running abnormally fast, or resorting to special fuel.It would be interesting to consider the application of superchargers to aero engines with this idea of obtaining large outputs from small engines. Given good design, an actual increase in horse-power for a given weight would result.

Fuel Atomization in Small Jet Engines

2002 ◽  
Author(s):  
Yeshayahou Levy ◽  
Semion Lipkin ◽  
Valery Nadvany ◽  
Valery Sherbaum
Keyword(s):  
Fuel Injection ◽  
High Energy ◽  
Operating Conditions ◽  
Fuel Vapor ◽  
Ignition Process ◽  
Jet Engines ◽  
Alternative Design ◽  
Fuel Supply ◽  
Small Engines ◽  
Supply Systems

Small and inexpensive jet engines are usually equipped with vaporizing fuel supply systems. This is in order to deliver low fuel flow-rates from relatively low-pressure fuel supply systems and the need for simple configuration. The difficulties associated with small engines are mainly during ignition or at high altitude re-lights, when the combustor is cold, air supply is poor, and fuel demand and pressure are low. Such conditions lead to poor atomization within the vaporizer resulting in very large droplets at its exit tip or even to a pool of liquid fuel within the combustor. Thus, there is no fuel vapor for ignition. Ignition is very difficult or even impossible under such conditions. Therefore, small engines are commonly equipped with dual fuel supply systems, either in the form of gaseous fuel for the ignition stage or with an additional higher-pressure supply line to the dedicated fuel nozzles for the purpose of ignition. Additional solutions involve the use of a large glow plug or high-energy pyrotechnic cartridges in the kilo-Joule range, to heat the combustor casing prior to ignition. The present work is concerned with the development of alternative and novel atomization systems, which would improve atomization at low pressures and consequently facilitate the ignition process, thus minimizing the need for supporting systems. The work refers to an alternative design for an existing vaporizer system of a small jet engine with 400 Nt of thrust. It focuses on an alternative design for the fuel injection within the vaporizer housing while maintaining all external dimensions and operating conditions unchanged. Three types of fuel nozzles were investigated: • a special impact atomizer, • a miniature pressure swirl atomizer, • a doublet atomizer involving two swirling nozzles (preliminary study only). Droplet size distribution under various nozzle pressure drops and air velocities were measured with Phase Doppler Particle Anemometry (PDPA) and global spray characteristics were obtained by photography. All modified atomization systems demonstrated improved performance and better atomization than the existing system. Initially, water was used as a liquid. At a later stage, the modified impact atomizer was tested and successful spark ignition was demonstrated.

Economic Decline in the English Industrial Revolution: The Gloucester Wool Trade, 1800–1840

1985 ◽  
Vol 45 (2) ◽  
pp. 427-433 ◽  
Author(s):  
Albion M. Urdank
Keyword(s):  
Industrial Revolution ◽  
Excess Capacity ◽  
Economic Decline ◽  
Steam Power ◽  
Small Engines ◽  
English Industrial Revolution

This study questions the concept of entrepreneurial failure, traditionally invoked to account for the demise of the Gloucestershire wool trade in the Industrial Revolution. Gloucester clothiers used steam power selectively because of the high cost of coal but on a more regular basis and at greater capacity than scholars have commonly admitted. Excess capacity due to overcapitalization accounted for the failure of mills with large engines; underutilization of steam accounted for the failure of mills with small engines. Both types of failure sprang from rational and entrepreneurial choices, and not from an unwillingness to innovate.

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