993 resultados para 165-999B
Resumo:
Growing concerns regarding fluctuating fuel costs and pollution targets for gas emissions, have led the aviation industry to seek alternative technologies to reduce its dependency on crude oil, and its net emissions. Recently blends of bio-fuel with kerosine, have become an alternative solution as they offer "greener" aircraft and reduce demand on crude oil. Interestingly, this technique is able to be implemented in current aircraft as it does not require any modification to the engine. Therefore, the present study investigates the effect of blends of bio-synthetic paraffinic kerosine with Jet-A in a civil aircraft engine, focusing on its performance and exhaust emissions. Two bio-fuels are considered: Jatropha Bio-synthetic Paraffinic Kerosine (JSPK) and Camelina Bio-synthetic Paraffinic Kerosine (CSPK); there are evaluated as pure fuels, and as 10% and 50% blend with Jet-A. Results obtained show improvement in thrust, fuel flow and SFC as composition of bio-fuel in the blend increases. At design point condition, results on engine emissions show reduction in NO x, and CO, but increases of CO is observed at fixed fuel condition, as the composition of bio-fuel in the mixture increases. Copyright © 2012 by ASME.
Resumo:
<正> 鲂属(Megalobrama)隶属于鲤科(Cyprinidae)的鲌亚科(Cultrinae),是一群较大型的经济鱼类,有的种已作为淡水养殖对象。关于鲂属的分类,虽经一些作者整理,但存在不少问题,因而长期未能使用正确的种名。易伯鲁和吴清江(1964)将鲂属鱼类归纳为3种,但个别种的种名厘订有误。Bǎnǎrescu(1970)将华鳊属(Sinibrama)划归为鲂属下的1个亚属,使鲂属共含5个种和亚种。华鳊属的鳔为2室,与鲂属有显著差别,