[Chongqing Guangdong education] engineering fluid mechanics reference materials of southwestjiaotonguniversity

education
- Engineering fluid mechanics - Chapter materials, examination materials - Southwest Jiaotong University 【】
The first 1 Homework
The first 1 This is a test
1、【 Single topic selection 】 According to the concept of continuous medium , Liquid particle refers to ：（ ）
A、 Molecules of liquid ;
B、 Solid particles in liquid ;
C、 Geometric points ;
D、 The geometric dimension is extremely small compared with the flow space , And microelements containing a large number of molecules .
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2、【 Single topic selection 】 The mass forces acting on the fluid include ：（ ）
A、 pressure ;
B、 Frictional resistance ;
C、 gravity ;
D、 surface tension .
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3、【 Single topic selection 】 Compare the gravitational field （ The force of mass is only gravity ） in , Unit mass force on water and mercury Z Water and Z Size of mercury ：（ ）
A、Z water ﹤Z mercury ;
B、Z water =Z mercury ;
C、Z water ﹥Z mercury ;
D、 Indefinite .
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4、【 Single topic selection 】 The international unit of unit mass force is ：（ ）
A、N;
B、 Pa;
C、N/kg;
D、m/s2
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5、【 Single topic selection 】 The factors directly related to Newton's law of internal friction are ：（ ）
A、 Shear stress and pressure ;
B、 Shear stress and shear deformation rate ;
C、 Shear stress and shear deformation ;
D、 Shear stress and flow velocity .
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6、【 Single topic selection 】 The dynamic viscosity of water increases with temperature ：（ ）
A、 increase ;
B、 Reduce ;
C、 unchanged ;
D、 Indefinite .
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7、【 Single topic selection 】 Viscosity of fluid motion The SI unit of is ：（ ）
A、m2/s
B、N/m2
C、kg/m
D、s/m2
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8、【 Single topic selection 】 Ideal fluids are characterized by ：（ ）
A、 Viscosity is constant ;
B、 Incompressible ;
C、 Cohesionless ;
D、 accord with pV=RT.
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9、【 Single topic selection 】 In fluid mechanics , Unit mass force refers to the force acting on （ ）
A、 Mass force per unit area of liquid
B、 Mass force per unit volume of liquid
C、 Mass force per unit mass of liquid
D、 Mass force per unit weight of liquid
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10、【 Single topic selection 】 The following statement about fluid viscosity is incorrect （ ）
A、 Viscosity is an inherent property of fluid
B、 Viscosity is a measure of the ability of a fluid to resist shear deformation rates in motion
C、 The viscosity of fluid has the dual function of transmitting motion and blocking motion
D、 The viscosity of the fluid increases with the increase of temperature
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11、【 Single topic selection 】 The following correct discussion about liquid particles and liquid micelles is （ ）
A、 Liquid micelles are larger than liquid particles
B、 Liquid micelles contain many liquid particles
C、 Liquid particles have no size , No quality
D、 Liquid particles are also called liquid micelles
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12、【 Single topic selection 】 A closed container filled with water , When it falls freely from the air （ Regardless of air resistance ）, Its unit mass force is （ ）
A、0
B、-g
C、mg
D、–mg
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13、【 Single topic selection 】 A closed container filled with water , When the earth is stationary , Its unit mass force is （ ）
A、 0
B、-g
C、mg
D、–mg
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14、【 Single topic selection 】 The ideal liquid is （ ）
A、 Liquid without shear stress and deformation
B、 An imaginary liquid that has no shear stress but is deformable
C、 A liquid in which the shear stress is linearly related to the shear deformation rate
D、 A liquid that has shear stress but does not deform
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15、【 Single topic selection 】 The velocity distribution in the liquid is known u－y As shown in the figure , Its shear stress distribution is （ ）
A、τ＝０
B、τ＝ constant
C、τ＝ky (k Constant )
D、 Not sure
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16、【 Single topic selection 】 The main reason for the resistance of moving fluid is that the fluid has （ ）.
A、 compressibility
B、 Expansibility
C、 Viscosity
D、 Mobility
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17、【 Single topic selection 】 Among the following groups , What belongs to mass force is （ ）.
A、 gravity 、 Inertial force
B、 pressure 、 Viscous force
C、 pressure 、 Viscous force
D、 pull 、 Shear force
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18、【 Single topic selection 】 Unit mass force refers to the force acting on the unit （ ） The mass force on the fluid .
A、 area
B、 Volume
C、 quality
D、 weight
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19、【 Single topic selection 】 At rest , The ratio of unit mass force borne by mercury and water is （ ）.
A、13.6
B、12.6
C、9.8
D、1
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20、【 Multiple choice 】 The mass forces acting on the fluid include （ ）
A、 pressure
B、 The frictional force
C、 gravity
D、 Inertial force
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21、【 Multiple choice 】 In Hydraulic Research , To simplify analytical reasoning , The following three hydrodynamic models are usually used （ ）
A、 Newtonian liquid model
B、 Ideal liquid model
C、 Incompressible liquid model
D、 Non Newtonian liquid model
E、 Continuum model
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22、【 Multiple choice 】 Which of the following fluids are Newtonian fluids （ ）
A、 air
B、 clean water
C、 The plasma
D、 gasoline
E、 slurry
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23、【 Multiple choice 】 In the following discussion about the vaporization pressure of fluid , What's not right is （ ）
A、 As the temperature of the liquid increases, the vaporization pressure increases
B、 As the temperature of the liquid increases, the vaporization pressure decreases
C、 The vaporization pressure of liquid varies with altitude
D、20ºC The vaporization pressure of water is １atm
E、100ºC The vaporization pressure of water is １atm
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24、【 Multiple choice 】 Which of the following fluids are non Newtonian （ ）
A、 air
B、 clean water
C、 blood
D、 alcohol
E、 slurry
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25、【 Multiple choice 】 The following statement about fluid viscosity is correct （ ）
A、 Viscosity is an inherent property of fluid
B、 Viscosity is a measure of the ability of a fluid to resist shear deformation rates in motion
C、 The viscosity of fluid has the dual function of transmitting motion and blocking motion
D、 The viscosity of gas increases with the increase of temperature
E、 The viscosity of liquid decreases with the increase of temperature
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26、【 Multiple choice 】 In the following options , The right ones （ ）
A、 The viscosity of fluid has the duality of transmitting motion and hindering motion
B、 Constant flow refers to the flow of moving elements that do not change with time
C、 Hydraulic jump is a local hydraulic phenomenon caused by the transition of open channel flow from rapid flow to slow flow
D、 The mass force of the equilibrium fluid is constant and tangent to the isobaric surface
E、 Seepage refers to the flow of fluid in porous media
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27、【 Judgment questions 】 An ideal fluid is one that does not consider viscosity 、 It doesn't really exist , Idealized fluid .（ ）
A、 correct
B、 error
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28、【 Judgment questions 】 Under the assumption of continuous medium , The changes of various physical quantities in liquid are continuous .（ ）
A、 correct
B、 error
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29、【 Judgment questions 】 Viscosity is the fundamental cause of energy loss in fluid motion .（ ）
A、 correct
B、 error
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30、【 Judgment questions 】 Newton's law of internal friction applies to all fluids .（ ）
A、 correct
B、 error
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31、【 Judgment questions 】 Newton's law of internal friction is only applicable to laminar flow in pipes .（ ）
A、 correct
B、 error
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32、【 Judgment questions 】 When the temperature rises , The viscosity of air decreases .（ ）
A、 correct
B、 error
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33、【 Judgment questions 】 The velocity gradient is essentially the viscosity of the fluid .（ ）
A、 correct
B、 error
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34、【 Judgment questions 】 Fluid is a kind of fluid when subjected to any external force , Matter that can be continuously deformed .（ ）
A、 correct
B、 error
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35、【 Judgment questions 】 Forces acting on fluids are usually divided into shear forces and elastic forces . （ ）
A、 correct
B、 error
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36、【 Judgment questions 】 The surface force of fluid is not only related to the external force of the acting surface area , But also with the size of the action area 、 Volume is related to density .（ ）
A、 correct
B、 error
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37、【 Judgment questions 】 Newton's law of internal friction shows , The viscous force is proportional to the positive pressure between the flow layers .（ ）
A、 correct
B、 error
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38、【 Judgment questions 】 Newton's law of internal friction , Viscosity coefficient μ and ν Are related to pressure and temperature .（ ）
A、 correct
B、 error
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39、【 Judgment questions 】 Bulk modulus K The bigger the value is. , The easier the liquid compresses .（ ）
A、 correct
B、 error
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40、【 Judgment questions 】 The internal friction of the liquid is directly proportional to the speed of the liquid .（ ）
A、 correct
B、 error
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41、【 Judgment questions 】 The flow velocity at the side wall is zero , Therefore, the velocity gradient here is zero .（ ）
A、 correct
B、 error
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42、【 Completion 】A、B It is two adjacent liquid layers ,A The layer velocity is greater than B Layer velocity . be A Layer pair B Layer shear stress τ1 B Layer pair A Layer shear stress τ2 . among τ1 Direction and flow direction of ,τ2 Direction and flow direction of ____.
A、
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43、【 Completion 】 The dimension of unit mass force is __________________; The dimension of kinematic viscosity is ; The dimension of dynamic viscosity is .
A、
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44、【 Completion 】 It is known that the velocity distribution in the section of the binary open channel is a parabola , Such as graphic , Then its shear stress distribution τ~y by Distribution , The maximum shear stress is It's about .
A、
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45、【 Completion 】 The most basic in fluid mechanics 、 The assumption throughout is Assume .
A、
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46、【 Completion 】 The figure shows the distribution of flow velocity at the cross section of the pipeline , Take out the water body from its corresponding part A, Then the direction and direction of the shear stress on the top surface of the water body , Direction and flow direction of bottom shear stress .
A、
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47、【 Completion 】 The plate area is 40×1125mm2, Thickness is 25mm, quality m=5kg, Along the coating thickness =1.0mm The slope of the oil moves downward at a constant speed , Its speed u=1.0m/s, The movement speed of the driving oil layer is in a linear distribution , Then the viscosity of the oil μ=,ν =( Density of oil ρ＝950 kg/m3).
A、
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48、【 Completion 】 Substances that flow easily in nature are called .
A、
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49、【 Completion 】 Kinematic viscosity And dynamic viscosity The relationship is = .
A、
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50、【 Completion 】 The viscosity of decreases with the increase of temperature .
A、
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51、【 Completion 】 Internal friction of ideal fluid motion = .
A、
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52、【 Completion 】 Water depth in stilling pool 2m and 3m The ratio of unit mass force at is .
A、
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The first 2 Homework
The first 3 Homework
The first 4 Homework
The first 2 This is a test
1、【 Single topic selection 】 In still liquid :（ ）
A、 Compressive stress
B、 Compressive stress and tensile stress
C、 Compressive stress 、 Shear stress
D、 Liquid level atmospheric pressure
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2、【 Single topic selection 】 The starting point of the relative pressure is : （ ）
A、 Absolute pressure
B、1 atmospheres
C、 Local atmospheric pressure
D、 Liquid level atmospheric pressure
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3、【 Single topic selection 】 The reading value of the metal pressure gauge is ：（ ）
A、 Absolute pressure
B、 Relative pressure
C、 Absolute pressure plus local atmospheric pressure
D、 Relative pressure plus local atmospheric pressure
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4、【 Single topic selection 】 Absolute pressure pabs And relative pressure p、 Vacuum pv、 Local atmospheric pressure pa The relationship between ：（ ）
A、pabs=p+pv
B、 p= pabs + pa
C、pv =pa- pabs
D、p= pv + pa
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5、【 Single topic selection 】 Put U V-shaped mercury manometer , among 1、2、3 The points are on the same horizontal plane , The pressure relation is ：（ ）
A、p1=p2=p3
B、p1＞p2＞p3
C、p1＜p2＜p3
D、p2＜p1＜p3
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6、【 Single topic selection 】 use U V-shaped mercury differential pressure gauge measures water pipe A、B The pressure difference between two points , The mercury surface is high hp=250mm,pA-pB by ：（ ）<img src="//img.inotgo.com/imagesLocal/202202/07/202202071738100680_27.jpg> A、13.33kPa
B、12.35 kPa
C、9.8 kPa
D、6.4 kPa
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7、【 Single topic selection 】 Open pool , Water depth 5m The relative pressure at is ：（ ）
A、5kPa
B、49 kPa
C、147 kPa
D、205 kPa
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8、【 Single topic selection 】 A rectangular flat plate placed vertically blocks water , Water depth ３m, Total hydrostatic pressure Ｐ The distance from the action point of to the water surface yD by ：（ ）
A、1.25m
B、1.5m
C、 2m
D、2.5m
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9、【 Single topic selection 】 The vacuum at a point is 65000Pa, The local atmospheric pressure is 0.1MPa, The absolute pressure at this point is ：（ ）
A、65000Pa
B、55000Pa
C、35000 Pa
D、165000 Pa
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10、【 Single topic selection 】 The stress center is ：（ ）
A、 The center of the submerged area
B、 The center of the pressure body
C、 Action point of total pressure
D、 Centroid of compression surface
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11、【 Single topic selection 】 The isobaric surface in the equilibrium liquid must be ：（ ）
A、 level
B、 Oblique plane
C、 Rotating paraboloid
D、 The surface orthogonal to the mass force
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12、【 Single topic selection 】 There is an inclined plane gate , When the upstream and downstream water levels rise 1 m when 〔 Dotted line position 〕, Total hydrostatic pressure on the gate ：（ ）
A、 Bigger
B、 Bigger
C、 unchanged
D、 Undetermined
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13、【 Single topic selection 】 A rectangular plane completely submerged in water , When rotating around its centroid axis to what position , Its pressure center coincides with its centroid ？（ ）
A、45 Tilt
B、60 Tilt
C、 level
D、 Vertical
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14、【 Single topic selection 】 Select the following correct isobaric surface ：（ ）
A、A-A
B、B-B
C、C-C
D、D-D
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15、【 Single topic selection 】 The water depth in the four containers shown in the figure is H, Then the maximum hydrostatic pressure on the bottom of the container is ：（ ）
A、a
B、b
C、c
D、d
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16、【 Single topic selection 】 There are two kinds of static liquids with different weights in the container , As shown in the figure , Act on the container A B The hydrostatic pressure distribution on the wall shall be ：（ ）<img src="//img.inotgo.com/imagesLocal/202202/07/202202071738100680_13.jpg> A、a
B、b
C、c
D、d
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17、【 Single topic selection 】 The absolute pressure at a certain point of the liquid is 58 kPa , Then the relative pressure at this point is （ ）
A、159.3 kPa
B、43.3 kPa
C、-58 kPa
D、-43.3 kPa
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18、【 Single topic selection 】 Container shown a Moderate to severe r1 The liquid , Containers b The density is r1 and r2 Two liquids , Then the surface in the two containers AB On The pressure body and pressure should be （ ）
A、 The pressure body is the same , And the pressure is equal
B、 The pressure body is the same , But the pressure is not equal
C、 The pressure body is the same , But the pressure is not equal
D、 The pressure body is different , But the pressure is equal
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19、【 Single topic selection 】 There is a water pump device , The vacuum pressure at a certain point in the suction pipe is equal to 3 m Water column height , The local atmospheric pressure is an engineering atmospheric pressure , Its corresponding absolute pressure value is equal to （ ）<img src="//img.inotgo.com/imagesLocal/202202/07/202202071738100680_48.jpg> A、3 m Water column height
B、7 m Water column height
C、－3 m Water column height
D、 None of the above information is correct
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20、【 Single topic selection 】 The liquid follows the container x The direction is uniformly accelerated in a straight line , Its pressure at equilibrium p Distribution is （ ）
A、f (x, y)
B、f (y, z)
C、 f (x, z)
D、f (z)
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21、【 Single topic selection 】 The point pressure of a stationary fluid is the same as （ ） irrelevant .
A、 Location
B、 Direction
C、 Fluid type
D、 Acceleration of gravity
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22、【 Single topic selection 】 Pressure body （ ）
A、 It must be full of liquid
B、 There must be no liquid
C、 At least some of it is liquid
D、 At least some of it is liquid
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23、【 Single topic selection 】 Use a vertically placed flat plate to block water , Its water retaining area is A, The centroid is deep h, The horizontal inclination of the flat plate is θ, The hydrostatic pressure on the plate is （ ）
A、ρghAsinθ
B、ρghAcosθ
C、ρghAtanθ
D、ρghA
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24、【 Single topic selection 】 The isobaric equation of the equilibrium fluid is （ ）
A、
B、
C、
D、
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25、【 Single topic selection 】 The basic equation of hydrostatics is （ ）.
A、
B、
C、
D、
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26、【 Judgment questions 】 Equilibrium fluid cannot resist shear force .（ ）
A、 correct
B、 error
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27、【 Judgment questions 】 Stationary fluids do not show viscosity .（ ）
A、 correct
B、 error
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28、【 Judgment questions 】 Static fluid pressure can be transmitted in all directions without changing .（ ）
A、 correct
B、 error
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29、【 Judgment questions 】 Isobaric surface refers to the surface composed of points in the fluid with equal total mechanical energy .（ ）
A、 correct
B、 error
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30、【 Judgment questions 】 For equilibrium fluids , Its surface force is pressure .（ ）
A、 correct
B、 error
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31、【 Judgment questions 】 When the compression plane is placed horizontally , The pressure center coincides with the plane centroid .（ ）
A、 correct
B、 error
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32、【 Judgment questions 】 An engineering atmospheric pressure is equal to 98kPa, amount to 10m The pressure of the water column .（ ）
A、 correct
B、 error
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33、【 Judgment questions 】 The pressure on the free surface of a stationary liquid , It must be atmospheric pressure .（ ）
A、 correct
B、 error
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34、【 Judgment questions 】 The free surface of a stationary liquid is a horizontal plane , It is also an isobaric surface .（ ）
A、 correct
B、 error
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35、【 Judgment questions 】 When a stationary liquid is subjected to surface pressure , It will be transmitted to all points inside the liquid unchanged .（ ）
A、 correct
B、 error
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36、【 Judgment questions 】 When the relative pressure is zero , It is called absolute vacuum .（ ）
A、 correct
B、 error
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37、【 Judgment questions 】 When the absolute pressure at a certain point is less than an atmospheric pressure, that point is said to produce a vacuum .（ ）
A、 correct
B、 error
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38、【 Judgment questions 】 A still water surface with the same water depth must be an isobaric surface .（ ）
A、 correct
B、 error
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39、【 Judgment questions 】 Fluids in equilibrium cannot withstand tensile and shear forces , Can only withstand pressure , Its inner method The line direction acts on the action surface .（ ）
A、 correct
B、 error
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40、【 Judgment questions 】 In equilibrium fluid , The value of hydrostatic pressure at a certain point is independent of the orientation of the action surface in space .（ ）
A、 correct
B、 error
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41、【 Judgment questions 】 In equilibrium fluid , The value of hydrostatic pressure at a certain point is independent of the position of the action surface in space .（ ）
A、 correct
B、 error
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42、【 Judgment questions 】 The surface force on the equilibrium fluid includes normal pressure and tangential pressure .（ ）
A、 correct
B、 error
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43、【 Judgment questions 】 The action point of the total hydrostatic pressure of a vertical plate is the centroid of the plate .（ ）
A、 correct
B、 error
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44、【 Judgment questions 】 The hydrostatic pressure in all directions at the same point in the static liquid is equal .（ ）
A、 correct
B、 error
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45、【 Judgment questions 】 The mass force vector acting on any point in the equilibrium fluid is perpendicular to the isobaric surface passing through that point .（ ）
A、 correct
B、 error
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46、【 Judgment questions 】 The relative pressure must be positive .（ ）
A、 correct
B、 error
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47、【 Judgment questions 】 The picture shows a water container . When the bottle weight is not counted , The force acting on the ground is equal to the total pressure of water acting on the bottom of the bottle .（ ）<img src="//img.inotgo.com/imagesLocal/202202/07/202202071738100680_58.jpg> A、 correct
B、 error
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48、【 Judgment questions 】 The pressure center of the total hydrostatic pressure is the centroid of the area of the force bearing surface .（ ）
A、 correct
B、 error
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49、【 Judgment questions 】 The angle between an inclined plane of any shape and the water surface is a. Then the total hydrostatic pressure on the plane P=rgyDAsina.(yD It is the center of pressure D Coordinates of ,r Is the density of water ,A Is the slope area ) （ ）<img src="//img.inotgo.com/imagesLocal/202202/07/202202071738100680_33.jpg> A、 correct
B、 error
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50、【 Judgment questions 】 The pressure acting on the contact surface of two different liquids is mass force .（ ）
A、 correct
B、 error
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51、【 Judgment questions 】 Hydrostatic pressure is caused only by mass force .（ ）
A、 correct
B、 error
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52、【 Judgment questions 】 Two small holes are opened on the side wall of a water container A、B, And install a U V-shaped mercury differential pressure gauge , As shown in the figure . because A、B The hydrostatic pressure at two points is different , The mercury level must show Dh The difference between the .（ ）<img src="//img.inotgo.com/imagesLocal/202202/07/202202071738100680_65.jpg> A、 correct
B、 error
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53、【 Judgment questions 】 The buoyancy of an object in water is equal to the total hydrostatic pressure acting on the surface of the object .（ ）
A、 correct
B、 error
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54、【 Judgment questions 】 In a connector containing several different liquids , As long as the elevation of two points is the same , Then the pressure of these two points is the same .（ ）
A、 correct
B、 error
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55、【 Judgment questions 】 The liquid rotates with the container at an equal angular speed , The isobaric surface of a liquid is a rotating paraboloid .（ ）
A、 correct
B、 error
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56、【 Judgment questions 】 The liquid rotates with the container at an equal angular speed , The isobaric surface of a liquid is a rotating paraboloid .（ ）
A、 correct
B、 error
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57、【 Judgment questions 】 The water column height of the open glass piezometer is called the piezometer head .（ ）
A、 correct
B、 error
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58、【 Judgment questions 】 The relative pressure of the atmosphere is 760mmHg.（ ）
A、 correct
B、 error
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59、【 Completion 】 In liquid , Measuring pipe head (z + p/rg) The energy meaning of is .
A、
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60、【 Completion 】 In liquid , Position height z The energy meaning of is _______; Pressure height p/rg The energy meaning of is _______________.
A、
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61、【 Completion 】 The minimum value of vacuum pressure is _________; The maximum vacuum pressure is ____________.
A、
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62、【 Completion 】 The specific gravity is 0.81 The specific gravity of the object is 0.9 In the liquid , Then the ratio of exposed part volume to total volume is __________________.
A、
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63、【 Completion 】 Under the still water 3m The relative pressure at depth is ___________Pa.
A、
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64、【 Completion 】 The train accelerates uniformly a When leaving the station , The angle between the water surface and the horizontal plane measured in the water container in the carriage is θ, At this time, the acceleration of the train a=.
A、
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65、【 Completion 】 The area of the water retaining plate is 1m2, The submergence depth of the plate center is 2m, Then the total water pressure on the plate is __________N.
A、
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66、【 Completion 】 use U A-shaped mercury differential pressure gauge measures the pressure difference between the centers of two oil pipelines at the same elevation . The density of the oil is known ρ=800kg/m3, The density of mercury ρ’=13600kg/m3,U The height difference of the mercury surface on both sides of the tube is 25mm, Then the pressure difference between the centers of the two oil pipes is equal to ____________Pa.
A、
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67、【 Completion 】 The radius is R The sphere is immersed in a density of ρ In the liquid , The difference between the total water pressure on the lower half surface of the ball and the total water pressure on the lower half surface of the ball is ____.
A、
Reference material 【 】
The first 5 Homework
The first 6 Homework
The first 7 Homework
The first 3 This is a test
1、【 Single topic selection 】 Unsteady flow is （ ）
A、əu/ət=0
B、əu/ət≠0
C、əu/əS=0
D、əu/əS≠0
Reference material 【 】
2、【 Single topic selection 】 Constant flow is （ ）
A、 The flow changes regularly with time
B、 The moving elements at any spatial point in the flow field do not change with time
C、 The velocity distribution of each overflow section is the same
D、 The pressure of each overflow section is the same
Reference material 【 】
3、【 Single topic selection 】 One dimensional flow is （ ）
A、 Uniform flow
B、 The velocity distribution varies linearly
C、 The motion parameter is a function of spatial coordinates and time variables
D、 Constant flow
Reference material 【 】
4、【 Single topic selection 】 Uniform flow is （ ）
A、 The local acceleration is zero
B、 The migration acceleration is zero
C、 The centripetal acceleration is zero
D、 The resultant acceleration is zero
Reference material 【 】
5、【 Single topic selection 】 Variable diameter pipe , The diameter of d1=320mm,d2=160mm, Current Speed V1＝1.5m/s,V2 by ：（ ）
A、3m/s
B、4m/s
C、6m/s
D、9m/s
Reference material 【 】
6、【 Single topic selection 】 Equal diameter water pipe ,Ａ－Ａ It is the overflow section ,Ｂ－Ｂ Is the horizontal plane ,１、２、３、４ For each point on the surface （ Pictured ）, The physical quantity of motion of each point has the following relationship （ ）
A、p1=p2
B、p3=p4
C、
D、
Reference material 【 】
7、【 Single topic selection 】 In Bernoulli equation <img src="//img.inotgo.com/imagesLocal/202202/07/202202071738100680_57.jpg> A、 Mechanical energy per unit weight of liquid
B、 Mechanical energy per unit mass of liquid
C、 Mechanical energy per unit volume of liquid
D、 The total mechanical energy of the liquid passing through the flow section
Reference material 【 】
8、【 Single topic selection 】 Horizontally placed diffuser , If the head loss is ignored , The pressure at the centroid of the section has the following relationship （ ）<img src="//img.inotgo.com/imagesLocal/202202/07/202202071738100680_42.jpg> A、p1>p2
B、p1>p2
C、p1<p2
D、 Indefinite
Reference material 【 】
9、【 Single topic selection 】 The variation law of the total head line of viscous fluid is （ ）
A、 Descent along the way
B、 Rise along the way
C、 Keep level
D、 The first three situations are possible
Reference material 【 】
10、【 Single topic selection 】 The variation law of the head line of the piezometric pipe for viscous fluid is （ ）
A、 Descent along the way
B、 Rise along the way
C、 Keep level
D、 The first three situations are possible
Reference material 【 】
11、【 Single topic selection 】 The drawing shows the section of the suction pipe of the water pump A─A The hydrodynamic pressure varies with the installation height of the pump h And （ ）<img src="//img.inotgo.com/imagesLocal/202202/07/202202071738100680_36.jpg> A、 increase
B、 Reduce
C、 unchanged
D、 Indefinite
Reference material 【 】
12、【 Single topic selection 】 On the section where the open channel flows steadily and evenly 1、2 Install two pressure measuring tubes at two points , As shown in the figure , Then the height of the two pressure measuring tubes h1 And h2 The relationship is （ ）
A、h1 ＞ h2
B、 h1 ＜ h2
C、h1 = h2
D、 Undetermined
Reference material 【 】
13、【 Single topic selection 】 For pipes with pipe diameter changing along the way （ ）
A、 The head line of the piezometer can rise or fall
B、 The piezometer head line is always parallel to the total head line
C、 The head line of the piezometer will never rise along the way
D、 Piezometric tube The water head line cannot be lower than the pipe axis
Reference material 【 】
14、【 Single topic selection 】 As shown in the figure, the water flows out through the reducer , If the water level in the container remains unchanged , Then the water flow in the pipe belongs to （ ）
A、 Constant uniform flow
B、 Unsteady uniform flow
C、 Constant non-uniform flow
D、 Unsteady non-uniform flow
Reference material 【 】
15、【 Single topic selection 】 The relationship between the total head line of uniform flow and the head line of piezometric pipe is （ ）
A、 Parallel lines
B、 Parallel curves
C、 Non parallel straight lines
D、 Non parallel curves
Reference material 【 】
16、【 Single topic selection 】 Liquid motion always starts from （ ）
A、 Flow from high to low
B、 The large part of unit total mechanical energy flows to the small part of unit mechanical energy
C、 Flow from high pressure to low pressure
D、 Flow from high velocity to low velocity
Reference material 【 】
17、【 Single topic selection 】 As shown in the figure, the section suddenly shrinks, and the pipe passes through the viscous constant flow , The pipeline is equipped with U Tube mercury difference meter , Determine that the mercury level in the differential pressure gauge is （ ）
A、A higher than B
B、A lower than B
C、A、B Qi Ping
D、 Cannot determine the height
Reference material 【 】
18、【 Single topic selection 】 It is known that the velocity of a pipe flowing through the flow section is a rotating paraboloid distribution , Then the corresponding constant total flow momentum correction coefficient <img src="//img.inotgo.com/imagesLocal/202202/07/202202071738100680_31.jpg> A、1/3
B、2/3
C、1
D、4/3
Reference material 【 】
19、【 Single topic selection 】 It is known that the migration acceleration of a fluid flow is 1.5m/s2, Then the flow must be （ ）
A、 Constant flow
B、 Unsteady flow
C、 Uniform flow
D、 Nonuniform flow
Reference material 【 】
20、【 Single topic selection 】 The moving fluid is x The migration acceleration in the direction is （ ）
A、
B、
C、
D、
Reference material 【 】
21、【 Single topic selection 】 The overflow section refers to （ ） Cross section of .
A、 The overflow section refers to （ ） Cross section of .
B、 Streamline orthogonality
C、 Trace parallel
D、 The trace is orthogonal
Reference material 【 】
22、【 Multiple choice 】 Which of the following concepts belong to Euler （ ）
A、 Streamline
B、 Trace
C、 Liquid particle
D、 Liquid pellets
E、 Control body
Reference material 【 】
23、【 Multiple choice 】 Which of the following concepts belong to Lagrangian method （ ）
A、 Streamline
B、 Trace
C、 Liquid particle
D、 Liquid pellets
E、 Control body
Reference material 【 】
24、【 Multiple choice 】 When the streamline in the flow field is a straight line parallel to each other, the flow is （ ）
A、 Constant uniform flow
B、 Constant non-uniform flow
C、 Uniform flow
D、 Unsteady uniform flow
E、 Unsteady non-uniform flow
Reference material 【 】
25、【 Multiple choice 】 When the streamline in the flow field coincides with the trace ． This flow is （ ）
A、 Constant uniform flow
B、 Unsteady uniform flow
C、 Uniform flow
D、 Constant non-uniform flow
E、 Constant flow
Reference material 【 】
26、【 Multiple choice 】 When the liquid flow is constant and uniform , There must be （ ） Is equal to zero .
A、 Local acceleration
B、 Migration acceleration
C、 Hydraulic gradient J
D、 Piezometric pipe slope JP
E、J-JP
Reference material 【 】
27、【 Judgment questions 】 In fluid mechanics, the trajectory of each particle is studied by Euler method .（ ）
A、 correct
B、 error
Reference material 【 】
28、【 Judgment questions 】 The continuity equation represents the mass conservation of the control body .（ ）
A、 correct
B、 error
Reference material 【 】
29、【 Judgment questions 】 Constant flow must be uniform flow , Laminar flow must also be uniform .（ ）
A、 correct
B、 error
Reference material 【 】
30、【 Judgment questions 】 The trace and streamline are Lagrange and Euler Geometric description ; They are different versions of the same thing ; So the trace is the streamline , Streamline is trace .（ ）
A、 correct
B、 error
Reference material 【 】
31、【 Judgment questions 】 When liquid particles in the flow field pass through space points , A fluid in which all moving elements do not change with time is called a constant flow .（ ）
A、 correct
B、 error
Reference material 【 】
32、【 Judgment questions 】 At constant flow , The shape of the streamline does not change with time , The streamline does not necessarily coincide with the trace .（ ）
A、 correct
B、 error
Reference material 【 】
33、【 Judgment questions 】 The distribution law of dynamic water pressure on the section of gradually flowing water can be approximately regarded as the same as that of static water pressure .（ ）
A、 correct
B、 error
Reference material 【 】
34、【 Judgment questions 】 Streamline is a smooth curve , It can't be a broken line , Streamlines can intersect .（ ）
A、 correct
B、 error
Reference material 【 】
35、【 Judgment questions 】 A variable diameter pipe section ,A The section diameter is B Section diameter 2 times , be B The flow velocity in the section is A Section velocity 4 times .（ ）
A、 correct
B、 error
Reference material 【 】
36、【 Judgment questions 】 Incompressible liquid continuity differential equation Only for constant flow .（ ）
A、 correct
B、 error
Reference material 【 】
37、【 Judgment questions 】 The overflow section is perpendicular to the speed direction , therefore , It is a vertical plane perpendicular to the direction of velocity .（ ）
A、 correct
B、 error
Reference material 【 】
38、【 Judgment questions 】 If the density of the fluid does not change with space , Nor does it change with time , That is, the control volume remains unchanged , Then the fluid is incompressible .（ ）
A、 correct
B、 error
Reference material 【 】
39、【 Judgment questions 】 For ideal fluids , Fluid particles on the same streamline , Their energies are equal .（ ）
A、 correct
B、 error
Reference material 【 】
40、【 Judgment questions 】 When the mass force is negligible , When the overflow section is close to the plane , The static pressure on the flow section is distributed according to the law of static pressure in static liquid .（ ）
A、 correct
B、 error
Reference material 【 】
41、【 Judgment questions 】 The fluid pressure on the beam of free jet is atmospheric pressure everywhere .（ ）
A、 correct
B、 error
Reference material 【 】
42、【 Judgment questions 】 Both gradual flow and abrupt flow belong to non-uniform flow .（ ）
A、 correct
B、 error
Reference material 【 】
43、【 Judgment questions 】 The abrupt flow cannot be a constant flow . （ ）
A、 correct
B、 error
Reference material 【 】
44、【 Judgment questions 】 The total head line can rise along the flow direction , Can also fall . （ ）
A、 correct
B、 error
Reference material 【 】
45、【 Judgment questions 】 Hydraulic gradient is the head loss per unit length of flow .（ ）
A、 correct
B、 error
Reference material 【 】
46、【 Judgment questions 】 The flow in the diffusion pipe must be unsteady .（ ）
A、 correct
B、 error
Reference material 【 】
47、【 Judgment questions 】 Constant flow must be uniform flow , Unsteady flow must be non-uniform flow .（ ）
A、 correct
B、 error
Reference material 【 】
48、【 Judgment questions 】 The distribution law of pressure in uniform flow field is the same as that of hydrostatic pressure .（ ）
A、 correct
B、 error
Reference material 【 】
49、【 Judgment questions 】 The water head line of the measuring pipe can rise along the way 、 It can fall or remain unchanged .（ ）
A、 correct
B、 error
Reference material 【 】
50、【 Judgment questions 】 Total flow continuity equation v1A1 = v2A2 It is applicable to both constant flow and unsteady flow .（ ）
A、 correct
B、 error
Reference material 【 】
51、【 Judgment questions 】 There is a linear relationship between the dynamic water pressure and the depth of water on the gradual flow section .（ ）
A、 correct
B、 error
Reference material 【 】
52、【 Judgment questions 】 Water always flows from the section with large unit mechanical energy to the section with small unit mechanical energy .（ ）
A、 correct
B、 error
Reference material 【 】
53、【 Judgment questions 】 In constant flow, the total head line always drops along the flow , The head line of the piezometer can rise along the flow 、 Fall or level . （ ）
A、 correct
B、 error
Reference material 【 】
54、【 Judgment questions 】 The streamline and trace of liquid flow always coincide .（ ）
A、 correct
B、 error
Reference material 【 】
55、【 Judgment questions 】 The point velocity measured by pitot tube is the time average velocity .（ ）
A、 correct
B、 error
Reference material 【 】
56、【 Judgment questions 】 The head line of the piezometer can be higher than the total head line .（ ）
A、 correct
B、 error
Reference material 【 】
57、【 Judgment questions 】 Pressurized pipe flow in equal diameter pipes with increased pipe axis elevation along the flow direction , The pressure on the tube axis increases along the flow direction . （ ）
A、 correct
B、 error
Reference material 【 】
58、【 Judgment questions 】 Ideal liquid dynamic , The hydrodynamic pressure in all directions at any point is equal . （ ）
A、 correct
B、 error
Reference material 【 】
59、【 Completion 】 The constant total flow momentum equation is written as _______________________, The physical meaning of the equation is _____________________________________________________________________________.
A、
Reference material 【 】
60、【 Completion 】 In the constant total flow energy equation ,hw The energy meaning of is ____________________________________. Its dimension is ______________________________.
A、
Reference material 【 】
61、【 Completion 】 Open a small hole on the pipe wall of the pressurized pipe flow , If no liquid flows out of the hole , And inhale into the hole , This indicates the relative pressure of the liquid in the small hole _________ zero .( Fill in greater than 、 Equal to or less than ) For example, install a pressure measuring tube at the small hole , Then the liquid level in the pipe will ________.( Fill in higher than 、 Or below ) The position of the small hole .
A、
Reference material 【 】
62、【 Completion 】 In the constant total flow energy equation , v2／2g The energy meaning of is ______________________________________, Its dimension is .
A、
Reference material 【 】
63、【 Completion 】 Horizontally placed pipes , When the water flow in the pipe is constant and uniform , The average velocity along the section _, Hydrodynamic pressure along the way ______________.
A、
Reference material 【 】
64、【 Completion 】 The figure shows the bifurcation pipe , The section where the energy equation of a unit weight liquid can be written is _______________, The section where the energy equation of a liquid per unit weight cannot be written is _____________________.
A、
Reference material 【 】
65、【 Completion 】 The sectional area of a certain discharge A＝2m2, Through flow qv＝1m3／s, Kinetic energy correction factor α＝1.1, Then the average unit kinetic energy of the water passing section is _____________.
A、
Reference material 【 】
66、【 Completion 】 The figure shows a flat bottom tunnel with equal diameter , A control gate is set at the outlet . When the gate is closed ,A、B Two point pressure pA And pB The relationship is _____; When the gate is fully open ,A、B The two are located in the uniform flow section , The relationship is ___________________.<img src="//img.inotgo.com/imagesLocal/202202/07/202202071738100680_44.jpg> A、
Reference material 【 】
67、【 Completion 】 When applying the constant total flow energy equation , The two sections selected must be _________ section , However, there can be _______ flow .
A、
Reference material 【 】
68、【 Completion 】 There is a uniform pipe flow in a long straight pipe with equal diameter , Its pipe length 100 m, If the head loss is 0.8m, Then the hydraulic gradient is ___________.
A、
Reference material 【 】
69、【 Completion 】 The picture shows a large container connected to a vertical pipe , The water in the container flows into the atmosphere through a pipe . It is known that h1=1m,h2=3m. If head loss is not included , Then the flow rate at the outlet of the pipe is ________________.<img src="//img.inotgo.com/imagesLocal/202202/07/202202071738100680_23.jpg> A、
Reference material 【 】
70、【 Completion 】 Shown here 1、2 Two horizontally placed pipes of the same size . tube 1 Medium is the ideal liquid , tube 2 Medium is the actual liquid . When two pipes flow qv1 = qv2 when , Then the liquid level difference between the two pressure measuring tubes h1 And h2 The comparison is __________________.
A、
Reference material 【 】
71、【 Completion 】 Known velocity field ( among k Constant ), Then the streamline equation of the flow is .
A、
Reference material 【 】
72、【 Completion 】 The uniform flow of moving elements along the path that does not change with time is called .
A、
Reference material 【 】
73、【 Completion 】 Constant gradient flow through each point on the flow section The water heads are approximately equal .
A、
Reference material 【 】
74、【 Completion 】 Hydraulic gradient of constant uniform flow of actual fluid J With the corresponding piezometric pipe head line slope Jp The ratio of the J/ Jp = .
A、
Reference material 【 】
75、【 Completion 】 The gradient of the total head line of ideal fluid movement J= .
A、
Reference material 【 】
76、【 Completion 】 The mechanical energy upstream of the water flow must be Downstream mechanical energy .
A、
Reference material 【 】
77、【 Completion 】 Continuity equation of constant total flow 、 The velocity in Bernoulli equation and momentum equation is cross section .
A、
Reference material 【 】
78、【 Completion 】 The total head line of viscous total flow without energy input is always along the way Of .
A、
Reference material 【 】
The first 8 Homework
The first 9 Homework
The first 4 This is a test
1、【 Single topic selection 】 Speed v、 length l、 Acceleration of gravity g The dimensionless combination of is （ ）
A、
B、
C、
D、
Reference material 【 】
2、【 Single topic selection 】 Speed v、 density ρ、 Pressure p The dimensionless combination of is （ ）
A、
B、
C、
D、
Reference material 【 】
3、【 Single topic selection 】 Speed v、 length l、 Time t The dimensionless combination of is （ ）
A、
B、
C、
D、
Reference material 【 】
4、【 Single topic selection 】 Pressure difference Δp、 density ρ、 length l and Traffic Q The dimensionless combination of is （ ）
A、
B、
C、
D、
Reference material 【 】
5、【 Single topic selection 】 Carry out hydraulic model experiment , To achieve the dynamic similarity of pressurized pipe flow , The criterion to be chosen is （ ）
A、 Renault rule
B、 Froude rule
C、 Euler Criterion
D、 Bernoulli rule
Reference material 【 】
6、【 Single topic selection 】 density ρ, Dynamic viscosity coefficient µ, Current Speed v And length l The dimensionless combination of is （ ）
A、
B、
C、
D、
Reference material 【 】
7、【 Single topic selection 】 The physical meaning of Reynolds number indicates （ ）
A、 Ratio of viscous force to gravity
B、 The ratio of gravity to inertia
C、 Ratio of inertia force to viscous force
D、 Ratio of pressure to viscous force
Reference material 【 】
8、【 Single topic selection 】 Open channel flow model experiment , The length scale is ４． The model flow should be... Of the prototype flow （ ）
A、1/2
B、1/8
C、1/4
D、1/32
Reference material 【 】
9、【 Single topic selection 】 Model experiment of penstock , The length scale is ８, The flow of the model water pipe should be... Of the flow of the prototype water pipe （ ）
A、1/2
B、1/8
C、1/4
D、1/16
Reference material 【 】
10、【 Single topic selection 】 When the water flows in the turbulent rough area , The gravity and resistance of the model and prototype flow should be similar , As long as the relative roughness of the model and the prototype is equal , It can be used for model design （ ）
A、 Renault similarity criterion
B、 Froude's similarity criterion
C、 Euler similarity criterion
D、 Weber similarity criterion
Reference material 【 】
11、【 Single topic selection 】 Froude's similarity criterion considers that the dominant force is （ ）
A、 gravity
B、 surface tension
C、 Viscous resistance
D、 Turbulent resistance
Reference material 【 】
12、【 Single topic selection 】 Reynolds' similarity criterion considers that the main force is （ ）
A、 gravity
B、 pressure
C、 Viscous resistance
D、 Turbulent resistance
Reference material 【 】
13、【 Single topic selection 】 Carry out hydraulic model experiment , To achieve the dynamic similarity of open channel flow , The similar criterion to be chosen is ：（ ）
A、 Renault rule
B、 Froude rule
C、 Euler Criterion
D、 Other criteria
Reference material 【 】
14、【 Single topic selection 】 Loss coefficient along the way λ Dimension of （ Company ） by （ ）
A、m
B、m/s
C、m2/s
D、 Dimensionless
Reference material 【 】
15、【 Judgment questions 】 Similar conditions include boundary conditions 、 Continuous condition and smooth condition .（ ）
A、 correct
B、 error
Reference material 【 】
16、【 Judgment questions 】 The average flow velocity at the reduced section of the sluice hole is measured in the model vm=1.5m/s, Length scale used λl=25, Then the average flow velocity at the reduced section in the prototype vp=37.5m/s. （ ）
A、 correct
B、 error
Reference material 【 】
17、【 Judgment questions 】 Head loss coefficient along the way λ Dimension and Xie Cai coefficient c The dimensions of are the same .（ ）
A、 correct
B、 error
Reference material 【 】
18、【 Judgment questions 】 The physical meaning of Euler number is that it reflects the ratio of pressure to inertial force .
A、 correct
B、 error
Reference material 【 】
19、【 Judgment questions 】 For open channel model test , When using the same fluid , Then the flow scale can be pressed To calculate .
A、 correct
B、 error
Reference material 【 】
20、【 Judgment questions 】 In hydrodynamics , The acceleration scale is often written as
A、 correct
B、 error
Reference material 【 】
21、【 Completion 】 A model is designed according to the Renault similarity criterion , Model length scale λl =10, The selected model liquid is the same as the prototype . If the average velocity of a section of the model is measured vm=2500cm/s, Then the corresponding average velocity in the prototype vP=___________.
A、
Reference material 【 】
22、【 Completion 】 The model of a spillway is designed according to the gravity similarity criterion , Model length scale λl=50. Such as prototype traffic qvP=1500 m3/s, Then the model flow qm=_______.
A、
Reference material 【 】
23、【 Completion 】 The unit represents the size of physical quantity , And the dimension represents each physical quantity
A、
Reference material 【 】
24、【 Completion 】 When the viscous force is similar , Press Criterion calculation .
A、
Reference material 【 】
25、【 Completion 】 The basic dimension has Sex and uniqueness .
A、
Reference material 【 】
26、【 Completion 】 When using the quality dimension M、 Length dimension L、 Time dimension T When it is a basic dimension , Then the kinematic viscosity dimension dim =
A、
Reference material 【 】