简介:文章对影响柴油机NOX排放的因素进行分析,以某小型船用柴油机为例,通过对燃烧室结构及参数进行优化来控制其NOX排放,使其达到现阶段MARPOL公约附则Ⅵ修订案中对NOX排放的要求,同时保持较好的烟度和油耗。针对原来的燃烧室和改进后的燃烧室,在台架上作四种工况下的柴油机排放试验和外特性试验,并对试验结果进行分析研究,为小型船用柴油机排放控制提供一些思路。
简介:Green-Naghdi(G-N)theoryisafullynonlineartheoryforwaterwaves.SomeresearcherscallitafullynonlinearBoussinesqmodel.DifferentdegreesofcomplexityofG-Ntheoryaredistinguishedby"levels"wherethehigherthelevel,themorecomplicatedandpresumablymoreaccuratethetheoryis.IntheresearchpresentedhereacomparisonwasmadebetweentwodifferentlevelsofG-Ntheory,specificallylevelIIandlevelIIIG-Nrestrictedtheories.AlinearanalyticalsolutionforlevelIIIG-Nrestrictedtheorywasgiven.WavesonaplanarbeachandshoalingwaveswerebothsimulatedwiththesetwoG-Ntheories.ItwasshownforthefirsttimethatlevelIIIG-Nrestrictedtheorycanalsobeusedtopredictfluidvelocityinshallowwater.AlevelIIIG-NrestrictedtheoryisrecommendedinsteadofalevelIIG-Nrestrictedtheorywhensimulatingfullynonlinearshallowwaterwaves.