dstandardizationofsafetyproduction,andstrivetoachieve\nsicallysafe\safetysectionandisaunitofsecurityofficersresponsibleforminesafetydutiesandsupervisetheimplementationofthefollow-upto,andimplementationofthesystem,prosecution.PartImanagementsystems...Youcanusebrazierswhen,2--3metersfromthegroundandputthefireoutbeforethework,confirmthenofirebeforetheycanleave;Highway11non-staffinthemarginwithin50m,radiusoftheexcavationwork,andworkingwithin6metresoftheedgeandstayundertheumbrellaheading;12,blastingintothepitpersonnelmustfollowtheshootingguard'scommand,hidetosafety;13non-miningvehicles(includingbicycles,animal-drawnvehicle,motorvehicles,etc)willbebannedfromenteringthepitsandotherproductionareaonpainofheavyfines,resultinginaccidentstobeinvestigatedforresponsibility;14shootingthefollowingmechanicalsafetydistancesasfollows:categorynamemechanicalcannonsshallowholesandpopshootingexposedblastingunits:metersdiggingmachinerigcargunpowderotherequipment-pitequipment,especiallyanelectricalswitchandavarietyofsafetydevices,inadditiontospecifyingtheuseofresponsiblepersonnel,bananytouchingofotherpersonnel;16foundthatpowerlinesorcablesbreakinggroundbeforewithoutascertainingwhetherthecharged,prohibitsanyonefromtouching,andshouldleave5metersaway,andimmediatelynotifythepersonchecking;17withouttheleadership'sconsent,arenotallowedtotakethestrippedtrucks,watertankers,oiltankers,asaresultoftheca《第二章流体输送机械》习题解答

1）某盛有液体的圆筒容器，容器轴心线为铅垂向，液面水平，如附图中虚线所示。当容器以等角速度ω绕容器轴线旋转，液面呈曲面状。试证明： ①液面为旋转抛物面。 ②

。

③液相内某一点（r，z）的压强。式中ρ为液体密度。

解 题给条件下回旋液相内满足的一般式为

（常量）

取圆柱坐标如图，当Z=0,r=0,P=P0,∵C=P0

故回旋液体种，一般式为① 液面为P=P0的等压面

，为旋转抛物面

②

又

即：h0=∴H=2h0

dstandardizationofsafetyproduction,andstrivetoachieve\nsicallysafe\safetysectionandisaunitofsecurityofficersresponsibleforminesafetydutiesandsupervisetheimplementationofthefollow-upto,andimplementationofthesystem,prosecution.PartImanagementsystems...Youcanusebrazierswhen,2--3metersfromthegroundandputthefireoutbeforethework,confirmthenofirebeforetheycanleave;Highway11non-staffinthemarginwithin50m,radiusoftheexcavationwork,andworkingwithin6metresoftheedgeandstayundertheumbrellaheading;12,blastingintothepitpersonnelmustfollowtheshootingguard'scommand,hidetosafety;13non-miningvehicles(includingbicycles,animal-drawnvehicle,motorvehicles,etc)willbebannedfromenteringthepitsandotherproductionareaonpainofheavyfines,resultinginaccidentstobeinvestigatedforresponsibility;14shootingthefollowingmechanicalsafetydistancesasfollows:categorynamemechanicalcannonsshallowholesandpopshootingexposedblastingunits:metersdiggingmachinerigcargunpowderotherequipment-pitequipment,especiallyanelectricalswitchandavarietyofsafetydevices,inadditiontospecifyingtheuseofresponsiblepersonnel,bananytouchingofotherpersonnel;16foundthatpowerlinesorcablesbreakinggroundbeforewithoutascertainingwhetherthecharged,prohibitsanyonefromtouching,andshouldleave5metersaway,andimmediatelynotifythepersonchecking;17withouttheleadership'sconsent,arenotallowedtotakethestrippedtrucks,watertankers,oiltankers,asaresultoftheca③某一点（r,Z）的压强P:

2）直径0.2m、高0.4m的空心圆桶内盛满水，圆筒定该中心处开有小孔通大气，液面与顶盖内侧面齐平，如附图所示，当圆筒以800rpm转速绕容器轴心线回旋，问：圆筒壁内侧最高点与最低点的液体压强各为多少？

解

取圆柱坐标如图，当Z=0,r=0, P=P0 ,∴C=P0

故回旋液体种，一般式为 B点：

Z=0,r=R=0.1m,C

点:Z=-0.4m,r=0.1m,

3）以碱液吸收混合器中的CO2的流程如附图所示。已知：塔顶压强为0.45at（表压），碱液槽液面与塔内碱液出口处垂直高度差为10.5m，碱液流量为10m3/h，输液管规格是φ57×3.5mm，管长共45m（包括局部阻力的当量管长），碱液密度

，粘度

，管壁粗糙度

。试求：①输送每千克

质量碱液所需轴功，J/kg。②输送碱液所需有效功率，W。

解 ①

dstandardizationofsafetyproduction,andstrivetoachieve\nsicallysafe\safetysectionandisaunitofsecurityofficersresponsibleforminesafetydutiesandsupervisetheimplementationofthefollow-upto,andimplementationofthesystem,prosecution.PartImanagementsystems...Youcanusebrazierswhen,2--3metersfromthegroundandputthefireoutbeforethework,confirmthenofirebeforetheycanleave;Highway11non-staffinthemarginwithin50m,radiusoftheexcavationwork,andworkingwithin6metresoftheedgeandstayundertheumbrellaheading;12,blastingintothepitpersonnelmustfollowtheshootingguard'scommand,hidetosafety;13non-miningvehicles(includingbicycles,animal-drawnvehicle,motorvehicles,etc)willbebannedfromenteringthepitsandotherproductionareaonpainofheavyfines,resultinginaccidentstobeinvestigatedforresponsibility;14shootingthefollowingmechanicalsafetydistancesasfollows:categorynamemechanicalcannonsshallowholesandpopshootingexposedblastingunits:metersdiggingmachinerigcargunpowderotherequipment-pitequipment,especiallyanelectricalswitchandavarietyofsafetydevices,inadditiontospecifyingtheuseofresponsiblepersonnel,bananytouchingofotherpersonnel;16foundthatpowerlinesorcablesbreakinggroundbeforewithoutascertainingwhetherthecharged,prohibitsanyonefromtouching,andshouldleave5metersaway,andimmediatelynotifythepersonchecking;17withouttheleadership'sconsent,arenotallowedtotakethestrippedtrucks,watertankers,oiltankers,asaresultoftheca

,查得

∴

②

4）在离心泵性能测定试验中，以2 泵汲入口处真空度为220mmHg，以孔板流量计及U形压差计测流量，孔板的孔径为35mm，采用汞为指示液，压差计读数

，孔流系数

，测得轴功率为1.92kW，已知泵的进、出口

截面间的垂直高度差为0.2m。求泵的效率η。

解

5）IS65-40-200型离心泵在V m3/h He m 7.5 13.2 时的“扬程～流量”数据如下： 12.5 12.5 15 11.8