华工流体力学复习提纲市公开课特等奖市赛课微课一等奖PPT课件.pptx

单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,Chapter 2,Fluid flow,流体流动,fluid statics and its application,Nature of fluids,Density,密度,Incompressible fluid,不可压缩流体,Compressible fluid,可压缩流体,Pressure,压强,(,压力,),Independent of direction,Unit,SI,制：,N/m,2,或,Pa,，,mmHg,，,mH,2,O,P,g,=P,abs,P,atm,P,v,=P,atm,-P,abs,第1页,Hydrostatic equilibrium,静力学方程,hydrostatic equation application,应用,U tube manometer,U,形压差计计算式,Limitation:,适用：静止、连续同种不可压缩性流体,；,Incompressible fluid,、,Continuous fluid,压力形式,能量形式,第2页,Solution:,图,(a)p=Rg(,m,-),；,图,(b)p=Rg(,m,-,空,)=Rg,m,；,图,(c)p=Rg(,m,-,E,),图,(d)p=Rg,m,-hg,。,第3页,Chapter3,Fluid-flow phenomena,流体流动现象,Ideal fluid,理想流体,Has zero viscosity,Potential flow has two characteristics:,Irrigational flow,There is no friction loss,第4页,Newtonian fluid,牛顿型流体,the proportionality constant,For gas,it increases with temperature,For liquid,it decreases with temperature,1PaS=10 P,（,泊）,=1000 cP,(,厘 泊,),一、,牛顿粘性定律,第5页,Laminar flow,层流,/,滞流,fluid flows in parallel straight lines,.,without lateral mixing,Laminar and turbulent flow,滞流和湍流,Turbulent flow,湍流,fluid moves erratically in form of crosscurrents and eddies,第6页,Reynolds number,雷诺准数,Re,2100,flow is laminar flow,滞流,Re,4000,flow is turbulence,湍流2100 Re4000,a transition,flow,过渡流,第7页,Flow in boundary layers,边界层定义,Laminar and turbulent flow in boundary layers,Boundary-layer formation in straight tubes,流体在管内边界层发展,Boundary-layer separation and wake formation,边界层分离,第8页,Chapter 4,basic equations of fluid flow,流体动力学,Mass balance,连续性方程,incompressible fluid,flow through the station a and b,第9页,Mechanical energy balance,柏努力方程,J/kg,m,pa,应用范围,For incompressible flow(,不可压缩流体,.),2.Without friction loss,3.For unit,第10页,Chap5,Incompressible flow in pipes and channels,流体流动阻力,=4,f,Shear stress and skin friction in pipes,直管阻力,直管阻力通式（范宁公式,Flow in noncircular channel,非圆形管内流动阻力,当量直径直径,d,e,代替非圆形管,d,第11页,Velocity distribution in a pipe,流体在圆管内速度分布,层流流动时，平均速度与最大速度关系：,u=0.5u,max,湍流流动时，平均速度与最大速度关系：,u=0.87u,max,第12页,Hagen-Poiseuille equation,哈根一泊谡叶公式,Turbulent flow in pipes,湍流流动,Laminar flow in pipes,层流流动,friction factor and friction coefficient chart,莫狄（,Moody,）摩擦因数图,第13页,Friction from changes in velocity or direction,局部阻力计算,Friction loss from sudden expansion of cross section,Friction loss from sudden contraction of cross section,Effect of fittings and valves,u,-,小管平均流速,第14页,Pipe Flow Systems,管路计算,Single Pipes,简单管路,Multiple,Pipes Systems,复杂管路,第15页,Chapter 6flow past immersed bodies,非均相物系分离,Terminal velocity,laminar,层流区,(,Stokes,区,),：,Re,p,1,Transition,(,过渡区,),：,Allen,law,turbulent,(,湍流区,),：,Newton,law,第16页,Separation equipments,Gravity settling processes,gravity settling chamber,Centrifugal settling processes,cyclone separator,Critical diameter,第17页,Filtration,discontinuous pressure filters,Principles of cake filtration,Constant-pressure filtration,【7-66】,第18页,Filtration equation of constant pressure,【7-70】,第19页,Continuous filtration,【7-74】,第20页,therefore,【7-75】,Washing filter cakes,第21页,Chapter8 transportation and metering of fluids,Developed head,Power requirement,power supplied to the pump drive from an external source,第22页,Suction lift and cavitation,no liquid can be drawn when,cavitation occurs,air bound,第23页,Suction lift,To avoid cavitation,the pressure in station 2,must,第24页,Centrifugal pump theory,Effects of speed and impeller size change,第25页,Characteristic curves;head-capacity relation,characteristic curve,第26页,Centrifugal-pump characteristics,characteristic curve,to decrease speed,to increase speed,第27页,System head curve,system curve,System curve,第28页,Operating point,system curve,Operating point,第29页,Operating point change,to decrease speed,to increase speed,Operational point,第30页,Operation in parallel and in series of centrifugal pump,in parallel,in series,第31页,Measurement of flowing fluids,Venturi meter,(8-34),第32页,Orifice meter,第33页,Area meters:Rot meters,Calibration,Installation,Direction of flow throughmodification,第34页,Picot tube,measure the local velocity,(8-48),第35页,Chapter 10,Heat Transfer,Conduction,(10-2),Direction of heat flow,conductivity,第36页,Convection,Newtons law of cooling,Coefficient depends on,the flow patterns,the thermal properties of the fluid,第37页,Radiation,The energy emitted is proportional to the fourth power of the absolute temperature.,第38页,Steady-state conduction,heat transfer through,flat slab,heat transfer through cylinder,第39页,Compound resistance in series,overall thermal resistance,total temperature drop,第40页,Chap11 Principles of heat flow in fluids,Countercurrent and parallel-current flows,第41页,parallel,第42页,Single-pass shell-and-tube condenser,t,1,t,2,Temperature,C,Length of tube,m,t,Temp of condensing vapor,T,Temp of cool fluid,第43页,Energy balances,q=m,h,C,ph,(,T,h,1,-T,h,2,)=,m,c,C,pc,(,t,c,2,-t,c,1,),(11-6),第44页,Overall heat-transfer coefficient,Special cases of the overall coefficient,第45页,Average temperature of fluid stream,Where,第46页,Chap12 Heat transfer to fluids without phase change,Heat transfer by forced convection in turbulent flow,(12-30),第47页,Chap13Heat transfer to fluids with phase change,Heat transfer from condensing vapors,Dropwise and film-type condensation,(13-14),vertical tubes,Horizontal tubes,noncondensing gas,第48页,Pool boiling of saturated liquid,natural convection,Nucleate boiling.,film boiling,第49页,Chap14,Radiation heat transfer,第50页,Chap.15,heat-exchange equipment,Shell-and-tube heat exchangers,multipass,Temperature difference,Enhance,Provision for thermal expansion,Operation in parallel and in series,第51页,