流体动力学连续介质力学介质流体质点无粘性流体连续介质假设流体
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流体动力学fluid dynamics连续介质力学mechanics of continuous media介质medium流体质点fluid particle无粘性流体nonviscous fluid, inviscid fluid连续介质假设continuous medium hypothesis流体运动学fluid kinematics水静力学hydrostatics液体静力学hydrostatics支配方程governing equation伯努利方程Bernoulli equation伯努利定理Bernonlli theorem毕奥-萨伐尔定律Biot-Savart law欧拉方程Euler equation亥姆霍兹定理Helmholtz theorem开尔文定理Kelvin theorem涡片vortex sheet库塔-茹可夫斯基条件Kutta-Zhoukowski condition 布拉休斯解Blasius solution达朗贝尔佯廖d''Alembert paradox雷诺数Reynolds number施特鲁哈尔数Strouhal number随体导数material derivative不可压缩流体incompressible fluid质量守恒conservation of mass动量守恒conservation of momentum能量守恒conservation of energy动量方程momentum equation能量方程energy equation控制体积control volume液体静压hydrostatic pressure涡量拟能enstrophy压差differential pressure流[动] flow流线stream line流面stream surface流管stream tube迹线path, path line流场flow field流态flow regime流动参量flow parameter流量flow rate, flow discharge涡旋vortex涡量vorticity涡丝vortex filament涡线vortex line涡面vortex surface涡层vortex layer涡环vortex ring涡对vortex pair涡管vortex tube涡街vortex street卡门涡街Karman vortex street马蹄涡horseshoe vortex对流涡胞convective cell卷筒涡胞roll cell涡eddy涡粘性eddy viscosity环流circulation环量circulation速度环量velocity circulation偶极子doublet, dipole驻点stagnation point总压[力] total pressure总压头total head静压头static head总焓total enthalpy能量输运energy transport速度剖面velocity profile库埃特流Couette flow单相流single phase flow单组份流single-component flow均匀流uniform flow非均匀流nonuniform flow二维流two-dimensional flow三维流three-dimensional flow准定常流quasi-steady flow非定常流unsteady flow, non-steady flow 暂态流transient flow周期流periodic flow振荡流oscillatory flow分层流stratified flow无旋流irrotational flow有旋流rotational flow轴对称流axisymmetric flow不可压缩性incompressibility不可压缩流[动] incompressible flow浮体floating body定倾中心metacenter阻力drag, resistance减阻drag reduction表面力surface force表面张力surface tension毛细[管]作用capillarity来流incoming flow自由流free stream自由流线free stream line外流external flow进口entrance, inlet出口exit, outlet扰动disturbance, perturbation分布distribution传播propagation色散dispersion弥散dispersion附加质量added mass ,associated mass收缩contraction镜象法image method无量纲参数dimensionless parameter几何相似geometric similarity运动相似kinematic similarity动力相似[性] dynamic similarity平面流plane flow势potential势流potential flow速度势velocity potential复势complex potential复速度complex velocity流函数stream function源source汇sink速度[水]头velocity head拐角流corner flow空泡流cavity flow超空泡supercavity超空泡流supercavity flow空气动力学aerodynamics低速空气动力学low-speed aerodynamics 高速空气动力学high-speed aerodynamics 气动热力学aerothermodynamics亚声速流[动] subsonic flow超声速流[动] supersonic flow锥形流conical flow楔流wedge flow叶栅流cascade flow非平衡流[动] non-equilibrium flow 细长体slender body细长度slenderness钝头体bluff body钝体blunt body翼型airfoil翼弦chord薄翼理论thin-airfoil theory构型configuration后缘trailing edge迎角angle of attack失速stall脱体激波detached shock wave波阻wave drag诱导阻力induced drag诱导速度induced velocity临界雷诺数critical Reynolds number 前缘涡leading edge vortex附着涡bound vortex约束涡confined vortex气动中心aerodynamic center气动力aerodynamic force气动噪声aerodynamic noise气动加热aerodynamic heating离解dissociation地面效应ground effect气体动力学gas dynamics稀疏波rarefaction wave热状态方程thermal equation of state 喷管Nozzle普朗特-迈耶流Prandtl-Meyer flow瑞利流Rayleigh flow可压缩流[动] compressible flow可压缩流体compressible fluid绝热流adiabatic flow非绝热流diabatic flow未扰动流undisturbed flow等熵流isentropic flow兰金-于戈尼奥条件Rankine-Hugoniot condition状态方程equation of state量热状态方程caloric equation of state完全气体perfect gas拉瓦尔喷管Laval nozzle马赫角Mach angle马赫锥Mach cone马赫线Mach line马赫数Mach number马赫波Mach wave当地马赫数local Mach number冲击波shock wave激波shock wave正激波normal shock wave斜激波oblique shock wave头波bow wave附体激波attached shock wave激波阵面shock front激波层shock layer压缩波compression wave反射reflection折射refraction散射scattering衍射diffraction绕射diffraction出口压力exit pressure超压[强] over pressure反压back pressure爆炸explosion爆轰detonation缓燃deflagration水动力学hydrodynamics液体动力学hydrodynamics泰勒不稳定性Taylor instability盖斯特纳波Gerstner wave斯托克斯波Stokes wave瑞利数Rayleigh number自由面free surface波速wave speed, wave velocity波高wave height波列wave train波群wave group波能wave energy表面波surface wave表面张力波capillary wave规则波regular wave不规则波irregular wave浅水波shallow water wave深水波deep water wave重力波gravity wave椭圆余弦波cnoidal wave潮波tidal wave涌波surge wave破碎波breaking wave船波ship wave非线性波nonlinear wave孤立子soliton水动[力]噪声hydrodynamic noise水击water hammer空化cavitation空化数cavitation number空蚀cavitation damage超空化流supercavitating flow水翼hydrofoil水力学hydraulics洪水波flood wave涟漪ripple消能energy dissipation海洋水动力学marine hydrodynamics 谢齐公式Chezy formula欧拉数Euler number弗劳德数Froude number水力半径hydraulic radius水力坡度hvdraulic slope高度水头elevating head水头损失head loss水位water level水跃hydraulic jump含水层aquifer排水drainage排放量discharge壅水曲线back water curve压[强水]头pressure head过水断面flow cross-section明槽流open channel flow孔流orifice flow无压流free surface flow有压流pressure flow缓流subcritical flow急流supercritical flow渐变流gradually varied flow急变流rapidly varied flow临界流critical flow异重流density current, gravity flow堰流weir flow掺气流aerated flow含沙流sediment-laden stream降水曲线dropdown curve沉积物sediment, deposit沉[降堆]积sedimentation, deposition沉降速度settling velocity流动稳定性flow stability不稳定性instability奥尔-索末菲方程Orr-Sommerfeld equation涡量方程vorticity equation泊肃叶流Poiseuille flow奥辛流Oseen flow剪切流shear flow粘性流[动] viscous flow层流laminar flow分离流separated flow二次流secondary flow近场流near field flow远场流far field flow滞止流stagnation flow尾流wake [flow]回流back flow反流reverse flow射流jet自由射流free jet管流pipe flow, tube flow内流internal flow拟序结构coherent structure猝发过程bursting process表观粘度apparent viscosity运动粘性kinematic viscosity动力粘性dynamic viscosity泊poise厘泊centipoise厘沱centistoke剪切层shear layer次层sublayer流动分离flow separation层流分离laminar separation湍流分离turbulent separation分离点separation point附着点attachment point再附reattachment再层流化relaminarization起动涡starting vortex驻涡standing vortex涡旋破碎vortex breakdown涡旋脱落vortex shedding压[力]降pressure drop压差阻力pressure drag压力能pressure energy型阻profile drag滑移速度slip velocity无滑移条件non-slip condition壁剪应力skin friction, frictional drag壁剪切速度friction velocity磨擦损失friction loss磨擦因子friction factor耗散dissipation滞后lag相似性解similar solution局域相似local similarity气体润滑gas lubrication液体动力润滑hydrodynamic lubrication浆体slurry泰勒数Taylor number纳维-斯托克斯方程Navier-Stokes equation牛顿流体Newtonian fluid边界层理论boundary later theory边界层方程boundary layer equation边界层boundary layer附面层boundary layer层流边界层laminar boundary layer湍流边界层turbulent boundary layer温度边界层thermal boundary layer边界层转捩boundary layer transition边界层分离boundary layer separation边界层厚度boundary layer thickness 位移厚度displacement thickness动量厚度momentum thickness能量厚度energy thickness焓厚度enthalpy thickness注入injection吸出suction泰勒涡Taylor vortex速度亏损律velocity defect law形状因子shape factor测速法anemometry粘度测定法visco[si] metry流动显示flow visualization油烟显示oil smoke visualization孔板流量计orifice meter频率响应frequency response油膜显示oil film visualization阴影法shadow method纹影法schlieren method烟丝法smoke wire method丝线法tuft method氢泡法nydrogen bubble method相似理论similarity theory相似律similarity law部分相似partial similarity定理pi theorem, Buckingham theorem 静[态]校准static calibration动态校准dynamic calibration风洞wind tunnel激波管shock tube激波管风洞shock tube wind tunnel 水洞water tunnel拖曳水池towing tank旋臂水池rotating arm basin扩散段diffuser测压孔pressure tap皮托管pitot tube普雷斯顿管preston tube斯坦顿管Stanton tube文丘里管Venturi tubeU形管U-tube压强计manometer微压计micromanometer多管压强计multiple manometer静压管static [pressure]tube流速计anemometer风速管Pitot- static tube激光多普勒测速计laser Doppler anemometer, laser Doppler velocimeter 热线流速计hot-wire anemometer热膜流速计hot- film anemometer流量计flow meter粘度计visco[si] meter涡量计vorticity meter传感器transducer, sensor压强传感器pressure transducer热敏电阻thermistor示踪物tracer时间线time line脉线streak line尺度效应scale effect壁效应wall effect堵塞blockage堵寒效应blockage effect动态响应dynamic response响应频率response frequency底压base pressure菲克定律Fick law巴塞特力Basset force埃克特数Eckert number格拉斯霍夫数Grashof number努塞特数Nusselt number普朗特数prandtl number雷诺比拟Reynolds analogy施密特数schmidt number斯坦顿数Stanton number对流convection自由对流natural convection, free convec-tion强迫对流forced convection热对流heat convection质量传递mass transfer传质系数mass transfer coefficient热量传递heat transfer传热系数heat transfer coefficient对流传热convective heat transfer辐射传热radiative heat transfer动量交换momentum transfer能量传递energy transfer传导conduction热传导conductive heat transfer热交换heat exchange临界热通量critical heat flux浓度concentration扩散diffusion扩散性diffusivity扩散率diffusivity扩散速度diffusion velocity分子扩散molecular diffusion沸腾boiling蒸发evaporation气化gasification凝结condensation成核nucleation计算流体力学computational fluid mechanics多重尺度问题multiple scale problem伯格斯方程Burgers equation对流扩散方程convection diffusion equationKDU方程KDV equation修正微分方程modified differential equation拉克斯等价定理Lax equivalence theorem数值模拟numerical simulation大涡模拟large eddy simulation数值粘性numerical viscosity非线性不稳定性nonlinear instability希尔特稳定性分析Hirt stability analysis相容条件consistency conditionCFL条件Courant- Friedrichs- Lewy condition ,CFL condition 狄里克雷边界条件Dirichlet boundary condition熵条件entropy condition远场边界条件far field boundary condition流入边界条件inflow boundary condition无反射边界条件nonreflecting boundary condition数值边界条件numerical boundary condition流出边界条件outflow boundary condition冯.诺伊曼条件von Neumann condition近似因子分解法approximate factorization method人工压缩artificial compression人工粘性artificial viscosity边界元法boundary element method配置方法collocation method能量法energy method有限体积法finite volume method流体网格法fluid in cell method, FLIC method通量校正传输法flux-corrected transport method通量矢量分解法flux vector splitting method伽辽金法Galerkin method积分方法integral method标记网格法marker and cell method, MAC method特征线法method of characteristics直线法method of lines矩量法moment method多重网格法multi- grid method板块法panel method质点网格法particle in cell method, PIC method质点法particle method预估校正法predictor-corrector method投影法projection method准谱法pseudo-spectral method随机选取法random choice method激波捕捉法shock-capturing method激波拟合法shock-fitting method谱方法spectral method稀疏矩阵分解法split coefficient matrix method不定常法time-dependent method时间分步法time splitting method变分法variational method涡方法vortex method隐格式implicit scheme显格式explicit scheme交替方向隐格式alternating direction implicit scheme, ADI scheme 反扩散差分格式anti-diffusion difference scheme紧差分格式compact difference scheme守恒差分格式conservation difference scheme克兰克-尼科尔森格式Crank-Nicolson scheme杜福特-弗兰克尔格式Dufort-Frankel scheme指数格式exponential scheme戈本诺夫格式Godunov scheme高分辨率格式high resolution scheme拉克斯-温德罗夫格式Lax-Wendroff scheme蛙跳格式leap-frog scheme单调差分格式monotone difference scheme保单调差分格式monotonicity preserving diffe-rence scheme穆曼-科尔格式Murman-Cole scheme半隐格式semi-implicit scheme斜迎风格式skew-upstream scheme全变差下降格式total variation decreasing scheme TVD scheme 迎风格式upstream scheme , upwind scheme计算区域computational domain物理区域physical domain影响域domain of influence依赖域domain of dependence区域分解domain decomposition维数分解dimensional split物理解physical solution弱解weak solution黎曼解算子Riemann solver守恒型conservation form弱守恒型weak conservation form强守恒型strong conservation form散度型divergence form贴体曲线坐标body- fitted curvilinear coordi-nates[自]适应网格[self-] adaptive mesh适应网格生成adaptive grid generation自动网格生成automatic grid generation数值网格生成numerical grid generation交错网格staggered mesh网格雷诺数cell Reynolds number数植扩散numerical diffusion数值耗散numerical dissipation数值色散numerical dispersion数值通量numerical flux放大因子amplification factor放大矩阵amplification matrix阻尼误差damping error离散涡discrete vortex熵通量entropy flux熵函数entropy function分步法fractional step method。
第一章绪论质量力:质量力是作用在流体的每个质点上的力。
流体质点:流体中宏观尺寸无穷小、而微观尺寸无穷大的任一物理实体。
表面力:是作用在所考虑流体表面上的力,其大小与被作用的表面积成正比。
是毗邻流体或其他物体作用在流体隔离体表面上的直接施加的接触力应力:单位面积上的作用力法向应力:单位面积上的法向力(正应力)—流体的压强切向应力:单位面积上的切向力—切应力τ惯性:是物体维持原有运动状态的能力的性质。
密度:单位体积流体所具有的质量容重:单位体积的流体受到的重力流体的黏滞性:流体内部质点间或流层间因相对运动而产生内摩擦力以反抗相对运动的性质,此内摩擦力称为流体的黏滞力.切应力:流层间单位面积上的内摩擦力速度梯度:速度沿垂直于速度方向y的变化率动力黏度μ的物理意义:单位速度梯度下的切应力运动黏度:流体的动力黏度与密度的比值牛顿流体:符合牛顿内摩擦定律的流体。
非牛顿流体:不符合牛顿内摩擦定律的流体。
流体的压缩性:流体受压,体积缩小,密度增大的性质流体的热胀性:流体受热,体积膨胀,密度减小的性质压缩系数:当温度保持不变时,单位压强增量引起流体密度的相对变化率流体的弹性模量:压缩系数的倒数热胀系数:表示当压强保持不变时,单位温度增量引起液体密度的相对变化率如果把两端开口的玻璃细管竖立在液体中,液体就会在细管中上升或下降一定高度,这种现象称为毛细管现象,对应的细管称为毛细管表面张力系数:单位长度上的表面张力值接触角概念: 当液体与固体壁面接触时形成曲面, 在曲面和管壁交接处,曲面的切线与管壁的夹角,称为接触角α可压缩流体:流体密度随压强变化不能忽略的流体。
理想流体:没有粘性的流体。
易流动性:静止时不能承受切向力,运动时抵抗剪切变形的能力。
三大模型:连续介质模型、不可压缩模型、理想流体模型。
连续介质假设是流体力学中第一个带根本性的假设连续介质模型:认为液体中充满一定体积时不留任何空隙,其中没有真空,也没有分子间隙,认为液体是连续介质,由此抽象出来的便是连续介质模型。
Chapter 1 Fluid statics 流体静力学1. 连续介质假定(Continuum assumption):The real fluid is considered as no -gap continuousmedia, called the basic assumption of continuity of fluid, or the continuum hypothesis of fluid. 流体是由连续分布的流体质点(fluid particle)所组成,彼此间无间隙。
它是流体力学中最基本的假定,1755年由欧拉提出。
在连续性假设之下,表征流体状态的宏观物理量在空间和时间上都是连续分布的,都可以作为空间和时间的函数。
2. 流体质点(Fluid particle ): A fluid element that is small enough with enough moles to makesure that the macroscopic mean density has definite value is defined as a Fluid Particle. 宏观上足够小,微观上足够大。
3. 流体的粘性(Viscosity ): is an internal property of a fluid that offers resistance to sheardeformation. It describes a fluid's internal resistance to flow and may be thought as a measure of fluid friction. 流体在运动状态下抵抗剪切变形的性质,称为黏性或粘滞性。
它表示流体的部流动阻力,也可当做一个流体摩擦力量。
The viscosity of a gas increases with temperature, the viscosity of a liquid decreases with temperature. 4. 牛顿摩擦定律(Newton’s law of viscosity ):5. The dynamic viscosity (动力黏度)is also called absolute viscosity (绝对黏度). The kinematicviscosity (运动黏度)is the ratio of dynamic viscosity to density.6. Compressibility (压缩性):As the temperature is constant, the magnitude ofcompressibility is expressed by coefficient of volume compressibility (体积压缩系数) к , a relative variation rate (相对变化率) of volume per unit pressure.The bulk modulus of elasticity (体积弹性模量) E is the reciprocal of coefficient of volumecompressibility к.7. 流体的膨胀性(expansibility; dilatability):The coefficient of cubical expansion (体积热膨胀系数) αt is the relative variation rate of volume per unit temperature change.8. 表面力Surface tension : A property resulting from the attractive forces between molecules.σ-----单位长度所受拉力9. 表面力 Surface force ——is the force exerted on the contact surface by the contacted fluidor other body. Its value is proportional to contact area. 作用在所研究流体外表面上与表du dzτμ=μνρ=面积大小成正比的力。
第一章连续介质假设:把流体当作是由密集质点构成的、内部无空隙的连续体来考虑。
表面力:作用在流体表面上的力;质量力:作用在所取流体体积内每个质点上的力;单位2/m s牛顿内摩擦定律:dudyτμ=μ动力粘度系数,υ运动粘度系数:μυρ=; 无粘性流体:指无粘性,0μ=的流体;不可压缩流体:指流体的每个质点在运动全过程中,密度不变化的流体。
常温常压下气体状态方程:pRT ρ=第二章静止流体的应力特征1.应力方向沿作用面的内法线方向;2.静压强的大小与作用面方位无关。
等压面:流体中压强相等的空间点构成的面(平面或曲面)称为等压面。
重力作用下流体静压强分布o p p gh ρ=+推论:静压强的大小与液体的体积无关两点的压强差等于两点之间单位面积垂直液柱的重量在平衡状态下,液体内任意一点压强的变化等值地传递到其他各点。
压强的度量:绝对压强:流体实有的全部压强相对压强:绝对压强与当地大气压的差值真空度:指绝对压强不足当地大气压的差值,即相对压强的负值v a abs p p p =-;p z c gρ+=,c 为测压管水头(总势能),其中z 为位置水头;pgρ压强水头; 作用在平面上的静水压力 图算法:p bs =(矩形板)b 为受压面宽度,s 为压强分布图的面积总压力的作用线通过压强分布图的形心 解析法:c p gh A ρ=(任意形状平面板)c h :受压面形心的淹没深度A :受压面面积作用在曲面上的静水压力x c x z p gh A p gvρρ==压力体:实压力体,虚压力体,混合压力体第三章描述流体运动的方法:拉格朗日法和欧拉法 拉格朗日法:以个别质点为观察对象,再将每个质点的运动情况汇总起来描述整个流体运动; 欧拉法:以流体运动的空间点作为观察对象,观察不同时刻各空间点上流体质点的运动,再将每个质点的运动情况汇总起来描述整个流体运动。
x x x x x x y z y y y y y x y z z z z zz x y z u u u ua u u u t x y z u u u u a u u u t x y z u u u u a u u u t x y z ∂∂∂∂=+++∂∂∂∂∂∂∂∂=+++∂∂∂∂∂∂∂∂=+++∂∂∂∂流动的分类恒定流和非恒定流:以时间为标准,若各空间点上的运动参数(速度,压强,密度等)都不随时间变化,这样的流动是恒定流,反之则为非恒定流。