Lighthill's eighth power law (original) (raw)
莱特希尔八次方律（英語：Lighthill's eighth power law）是气动声学中的一个定律，指由湍流产生的远场声功率与特征湍流速度的八次方成正比。这一定律由英国应用数学家詹姆斯·莱特希尔于1952年提出，可用于计算喷流噪声。 莱特希尔八次方律可表示为 其中 * 为远场声功率， * 为比例常数（或称为莱特希尔常数） * 为均匀流速度， * 为声速， * 为湍流的特征长度， * 为湍流的特征速度。 该定律适用于马赫数小于1的紧致湍流源。
| Property | Value |
|---|---|
| dbo:abstract | In aeroacoustics, Lighthill's eighth power law states that power of the sound created by a turbulent motion, far from the turbulence, is proportional to eighth power of the characteristic turbulent velocity, derived by Sir James Lighthill in 1952. This is used to calculate the total acoustic power of the jet noise. The law reads as where * is the acoustic power in the far-field, * is the proportionality constant (or Lighthill's constant), * is the uniform fluid density, * is the speed of sound, * is the characteristic length scale of the turbulent source and * is the characteristic velocity scale of the turbulent source. The eighth power is experimentally verified and found to be accurate for low speed flows, i.e., Mach number is small, . And also, the source has to be compact to apply this law. (en) 莱特希尔八次方律（英語：Lighthill's eighth power law）是气动声学中的一个定律，指由湍流产生的远场声功率与特征湍流速度的八次方成正比。这一定律由英国应用数学家詹姆斯·莱特希尔于1952年提出，可用于计算喷流噪声。 莱特希尔八次方律可表示为 其中 * 为远场声功率， * 为比例常数（或称为莱特希尔常数） * 为均匀流速度， * 为声速， * 为湍流的特征长度， * 为湍流的特征速度。 该定律适用于马赫数小于1的紧致湍流源。 (zh) |
| dbo:wikiPageID | 56466447 (xsd:integer) |
| dbo:wikiPageLength | 1431 (xsd:nonNegativeInteger) |
| dbo:wikiPageRevisionID | 991954596 (xsd:integer) |
| dbo:wikiPageWikiLink | dbr:Density dbr:Speed_of_sound dbr:Jet_noise dbc:Acoustics dbc:Fluid_dynamics dbr:Aeroacoustics dbr:Mach_number dbr:Sir_James_Lighthill |
| dbp:wikiPageUsesTemplate | dbt:Reflist |
| dcterms:subject | dbc:Acoustics dbc:Fluid_dynamics |
| rdfs:comment | 莱特希尔八次方律（英語：Lighthill's eighth power law）是气动声学中的一个定律，指由湍流产生的远场声功率与特征湍流速度的八次方成正比。这一定律由英国应用数学家詹姆斯·莱特希尔于1952年提出，可用于计算喷流噪声。 莱特希尔八次方律可表示为 其中 * 为远场声功率， * 为比例常数（或称为莱特希尔常数） * 为均匀流速度， * 为声速， * 为湍流的特征长度， * 为湍流的特征速度。 该定律适用于马赫数小于1的紧致湍流源。 (zh) In aeroacoustics, Lighthill's eighth power law states that power of the sound created by a turbulent motion, far from the turbulence, is proportional to eighth power of the characteristic turbulent velocity, derived by Sir James Lighthill in 1952. This is used to calculate the total acoustic power of the jet noise. The law reads as where The eighth power is experimentally verified and found to be accurate for low speed flows, i.e., Mach number is small, . And also, the source has to be compact to apply this law. (en) |
| rdfs:label | Lighthill's eighth power law (en) 莱特希尔八次方律 (zh) |
| owl:sameAs | wikidata:Lighthill's eighth power law dbpedia-zh:Lighthill's eighth power law https://global.dbpedia.org/id/4X7vu |
| prov:wasDerivedFrom | wikipedia-en:Lighthill's_eighth_power_law?oldid=991954596&ns=0 |
| foaf:isPrimaryTopicOf | wikipedia-en:Lighthill's_eighth_power_law |
| is dbo:knownFor of | dbr:James_Lighthill |
| is dbo:wikiPageWikiLink of | dbr:Jet_noise dbr:James_Lighthill dbr:Eighth_power |
| is dbp:knownFor of | dbr:James_Lighthill |
| is foaf:primaryTopic of | wikipedia-en:Lighthill's_eighth_power_law |