項(xiàng)目八：常規(guī)物理常數(shù)與性能分析任務(wù)七：黏度的測定黏度基本知識(shí)課程：工業(yè)分析中文Scenario8:PhysicalconstantsandperformancetestingTask7:DeterminationofviscosityBasicknowledgeofviscosityCourse:IndustrialAnalysisEglish1、粘度的概念粘度是液體的內(nèi)摩擦，是一層液體對(duì)另一層液體作相對(duì)運(yùn)動(dòng)時(shí)遇到的阻力。

粘度大表示內(nèi)摩擦力大，分子量越大，碳?xì)浣Y(jié)合越多，這種力量也越大。中文1、Theconceptofviscosity

Viscosityistheinternalfrictionofaliquid,whichistheresistanceencounteredwhenonelayerofliquidmovesrelativetoanother.Ahighviscosityindicatesahighinternalfrictionforce.Thelargerthemolecularweight,themorehydrocarbonscombine,andthisforceisalsogreater.Eglish

粘度與壓力、溫度的關(guān)系通常，壓力增加，油液的粘度增加；高壓時(shí)，壓力對(duì)粘度的影響較大，而中、低壓時(shí)壓力的影響不大。溫度對(duì)粘度的影響非常明顯，溫度上升、粘度下降。中文

Therelationshipbetweenviscosity,pressure,andtemperatureUsually,aspressureincreases,theviscosityoftheoilincreases;Athighpressure,pressurehasasignificantimpactonviscosity,whileatmediumandlowpressure,pressurehaslittleeffect.Theeffectoftemperatureonviscosityisverysignificant.Whenthetemperaturerises,theviscositywilldecrease.Eglish2、黏度的種類絕對(duì)黏度

運(yùn)動(dòng)黏度

條件黏度中文2、Typesofviscosityabsoluteviscosity

Kinematicviscosity

ConditionalviscosityEglish又稱為動(dòng)力粘度，以η

表示是指面積為1cm2的兩層液體，相互以1cm/s的速度相對(duì)移動(dòng)而應(yīng)克服的阻力。如阻力為10-5N，則該液體的絕對(duì)粘度為1，單位（SI）為Pa·s，中文為帕·秒。在溫度為t℃時(shí)液體的絕對(duì)粘度以ηt表示。（1）絕對(duì)粘度中文Absoluteviscosity,alsoknownasdynamicviscosity,isdeterminedbyηexpressItreferstotheresistancethattwolayersofliquidwithanareaof1cm2shouldovercomewhenmovingrelativetoeachotherataspeedof1cm/s.Iftheresistanceis10-5N,theabsoluteviscosityoftheliquidis1,andtheunit(SI)isPa·s.Theabsoluteviscosityoftheliquidatatemperatureoft℃representsasηT.（1）AbsoluteviscosityEglish（2）運(yùn)動(dòng)粘度中文（2）KinematicviscosityRepresentedbyvItistheratiooftheabsoluteviscosity

ηofaliquidtoitsdensityρ

atthesametemperature.Unit(SI)ism2/SAtatemperatureoft℃,thekinematicviscosityisexpressedinVt.Eglish包括恩氏粘度、賽氏粘度和雷氏粘度。恩氏粘度試樣在規(guī)定溫度下，從恩格勒粘度計(jì)中流出200mL所需的秒數(shù)，與同體積水在20℃溫度下流出所需的秒數(shù)的比值。單位為恩氏度，用符號(hào)ET表示。

（3）條件粘度恩氏黏度計(jì)中文ConditionalviscosityincludesEnglerviscosity,Sayboltviscosity,andRayleighviscosity.

Englerviscosity

Theratioofthenumberofsecondsrequiredforthesampletoflowoutof200mLfromtheEnglerviscometerataspecifiedtemperaturetothenumberofsecondsrequiredforthesamevolumeofwatertoflowoutatatemperatureof20℃.

TheunitisEngelsdegrees,representedbythesymbolET.

（3）ConditionalviscosityEnglerviscosimeterEglish賽氏粘度試樣在規(guī)定溫度下，從賽氏黏度計(jì)中流出60mL所需的時(shí)間，單位為s賽氏黏度計(jì)雷氏粘度試樣在規(guī)定溫度下，從雷氏黏度計(jì)中流出50mL所需的時(shí)間，單位為s中文

Sayboltviscosity

Thetimerequiredfor60mLofthesampletoflowoutoftheSayboltviscometeratthespecifiedtemperature,measuredinsecondsSayboltviscometerRayleighviscosity

Thetimerequiredfor50mLofthesampletoflowoutoftheRayleighviscometeratthespecifiedtemperature,measuredinsecondsEglish3、粘度測定的意義在一些種類的潤滑油標(biāo)準(zhǔn)中，是以運(yùn)動(dòng)粘度值來劃分牌號(hào)的。如冷凍機(jī)油、機(jī)械油等以50℃運(yùn)動(dòng)粘度的平均厘斯數(shù)劃分，內(nèi)燃機(jī)潤滑油、汽缸油、齒輪油等按100℃運(yùn)動(dòng)粘度的平均厘斯數(shù)劃分。粘度是潤滑油重要的質(zhì)量指標(biāo)，正確選擇一定粘度的潤滑油，可保證發(fā)動(dòng)機(jī)穩(wěn)定可靠的工作狀況。

中文3、ThesignificanceofviscositymeasurementInsometypesoflubricantstandards,gradesareclassifiedbasedontheirkinematicviscosityvalues.Forexample,refrigerationengineoil,mechanicaloil,etc.areclassifiedbasedontheaverageRiessof50℃kinematicviscosity,whileinternalcombustionenginelubricatingoil,cylinderoil,gearoil,etc.areclassifiedbasedontheaverageRiessof100℃kinematicviscosity.Visco