NVHEngineCoolingFanTestingSpecification&TargetItems(NVH发动机冷却风扇试验规范与项目目标)TestingSpecification–OnVehicle（试验规范——整车条件）Measurementenvironment（试验环境）Vehicleshouldbeinanapproximatelyfree-fieldenvironment(eithersemi-anechoicchamberoroutsidewithnomajorreflectingsurfacescloseby)（将车辆放置于一个近似于自由场的环境中或者半消声室中或附近没有较大反射物体的户外环境中）Measurementlocations（测试位置）3externalmicrophones,（三个置于车外的麦克风）Frontleft/rightatadistanceof1mandangleof45degfromthefrontbonnetcentre,1.6mhigh（前端左侧与右侧的麦克风置于离麦克风阀帽中心1米，左右分别45度离地高1.6米处）Frontmiddleatadistanceof1mfromthefancentre,1.6mhigh（前端中间的麦克风放置于在轴线方向距风扇中心1米，与地面距离1.6米处）Operatingconditions:（测试条件）Fanatnominalhighspeedoperatingcondition（风扇处于额定转速）Engineidling(warm)（发动机暖机后怠速）Dataacquisition（数据要求）Type:averaged(over30s)（模式：平均噪声）Samplerate:25600Hz（采样频率：25600赫兹）Frequencyresolution:1Hz（频率分辨率：1赫兹）Post-processingandplotting（数据处理与绘图）Thirdoctavespectrum（三分之一倍频程图）Narrowbandspectrum(0to1kHz)（狭带谱频率范围1至1千赫兹）TestingSpecification–ComponentinSemi-AnechoicChamber（测试规范——风扇单体在半消声室中）Measurementenvironment（试验环境）Semi-anechoicchamber（半消声室）Componentmounting（风扇单体带散热器及悬置）Aspersupplierstandardtest.Coolingfanattachedtoradiatormatrixandrigidlyattachedtoabase（与每个供应商的标准试验一样，冷却风扇连接散热器总成严格的连接到台架上）Measurementitems（测试条款）1microphoneatadistanceof1mfromthecentreofthefan,onthefanrotationalaxis（一个麦克风置于风扇轴线上，离风扇中心1米处）Fanoperatingspeed(ifpossible)（如果可能的话，操纵风扇转速）Operatingcondition（测试条件）Fanatnominalhighspeedoperatingcondition(operatingvoltagetobecheckedforinitialFordFocusmeasurementsandkeptconstantforallfurthermeasurements)（风扇处于额定转速下，加以和福克斯相同的额定电压并保持稳定以便下一步的测量）Dataacquisitionandpresentation（数据处理）Type:averaged(over30seconds)（模式：平均噪声）OveralllevelindB(A)（总声压级）Thirdoctavebands(atleast100Hzto20kHz)（三分之一倍频程图频率范围至少100赫兹至20000赫兹）Targetitemsummary（目标概述）Onvehicle:（整车中）Averageoveralllevelof3microphonemeasurements（三个麦克风的平均总声压级）Averagelevelofbladepassingfrequencypeak（叶片通过频率平均值）Component:（部件）OverallleveldB(A)（总声压级）Levelofthirdoctavebandcontainingbladepassin