Aerodynamics I

Июль 30, 2022

Содержание

2. Useful Info
3. Review The Principle of Dimensional Homogeneity (PDH)——a rule which is almost a self-evident axiom in physics
4. Review Basic Theorem
5. Review Flow similarity By definition, different flows are dynamically similar if: The streamline patterns are geometrically
6. Chapter 1: Introduction Schematic of the variable density tunnel (VDT) (From Baals, D. D. and Carliss,
7. Review Fluid static dynamics: Buoyance Consider the forces along y axis: Positive upward, then— Hydrostatic equation
8. Review Type of flow Continuum flow If the orders of magnitude of λ is smaller than
9. Review Inviscid flow versus Viscous flow Viscous flow: This transport on a molecular scale gives rise
10. Course Diagram
11. Chapter 1 Learning Targets
12. Chapter 1: Introduction 1.11 Viscous flow: Brief introduction on boundary layer At any point in flow
13. Chapter 1: Introduction In 1904, Prandtl put forward the concept of boundary layer: boundary layer—the region
14. Chapter 1: Introduction Question: Why are the gradients so large inside the layer? Inviscid, no friction,
15. Chapter 1: Introduction Note: the above two are reasonable for the layer attached on the surface
16. Chapter 1: Introduction Temperature profile through the layer: The curve of the temperature through the boundary
17. Chapter 1: Introduction μ variation with temperature: liquid (olive ; soybean- edible oil)—T increase, μ decrease;
18. Chapter 1: Introduction At standard sea level temperature: k=2.53×10-2J/(m)(s)(K) Proportional to the viscous coefficient essentially, i.e
19. Chapter 1: Introduction Re effect on boundary layer: Figure below: Development of boundary layer on plate
20. Chapter 1: Introduction The Reynolds number generally governs the nature of the viscous flow. The basic
21. Chapter 1: Introduction Fig.1.53: Comparison for the two velocity profiles—— Turbulent, relatively “plump”； Laminar, relatively “gradual”.
22. Chapter 1: Introduction By Eq.1.59: (τw)laminer The important fact: The shear stress of laminar flow is
23. Chapter 1: Introduction Homework: 1.11, 1.12 Questions for thinking: 1. After released, the hydrogen ball will
24. Chapter 1: Introduction 1.12 Applied aerodynamics: Aerodynamic coefficients—— Magnitudes and variations Applied aerodynamics: For the practical
25. Chapter 1: Introduction Lift, Drag and moment coefficient are the most frequently used technical terms in
26. Chapter 1: Introduction Fig.1.54, Typical drag coefficients of some bodies (fixed attitude) moving in a low
27. Chapter 1: Introduction Comparisons between Case b and d : One order of magnitude difference in
28. Chapter 1: Introduction Comparisons between Case c and d : Same dynamic pressures, drags are same
29. Chapter 1: Introduction Comparisons between Case b and e : Same diameter, but Ree=100·Reb, and CDe=2·CDb
30. Chapter 1: Introduction Note：Character parameter(per unit span)—the maximum windward cross-sectional area. The drag coefficients vary from
31. Chapter 1: Introduction Nature of drag: Axial force, Eq.1.8 becomes—— The aerodynamic drag on any body
32. Chapter 1: Introduction Fig.1.55, the comparison for the relative quantities of two types of drag of
33. Chapter 1: Introduction Thus, there are two types of typical aerodynamic shapes: Blunt body: Most part
34. Chapter 1: Introduction Variation of the plate drag at zero angle of attach with the Reynolds
35. Chapter 1: Introduction The figure listed above indicates that: Cf strongly depends on Re, of which
36. Chapter 1: Introduction NACA63-210 airfoil： With thickness, laminar airfoil—low angle—laminar flow—turbulent one at higher angle, the
37. Chapter 1: Introduction The drag on a low speed airplane : Seversky P-35, the typical fighter
38. Chapter 1: Introduction Question: As Mach number increases, how will the drag coefficient change ? Northrop
39. Chapter 1: Introduction Typical order of magnitude of lift coefficient: Fig.1.61-NACA63-210 airfoil ‘s lift curve—cl in
40. Chapter 1: Introduction Lift coefficient for full aircraft: Fig.1.62- CL-α curve for T38 : added the
41. Chapter 1: Introduction The order of magnitude of moment coefficient : Fig.1.63-cm.c/4 curve for NACA63-210 airfoil.
42. Chapter 1: Introduction Homework: p1.16、p1.18 Thinking work: Can all the drag come down to pressure drag
43. Chapter 1: Introduction The key points and difficult points in this chapter Key points: Fundamental aerodynamics
44. Chapter 1: Introduction Summation
45. Chapter 1: Introduction Summation
47. Скачать презентацию

Слайд 2

Useful Info

Слайд 3

Review
The Principle of Dimensional Homogeneity (PDH)——a rule which is almost a

self-evident axiom in physics

Dimensional Analysis

Dimensional analysis is based on the obvious fact that in an equation dealing with the real physical world, each term must have the same dimensions.

If an equation truly expresses a proper relationship between variables in a physical process, it will be dimensionally homogeneous; i.e. each of its additive terms will have the same dimensions.

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Review
Basic Theorem

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Review
Flow similarity
By definition, different flows are dynamically similar if:
The streamline patterns

are geometrically similar.
The distributions of V/V∞, p/p∞, T/T∞, etc., throughout the flow field are the same when plotted against common non-dimensional coordinates.
The force coefficients are the same.

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Chapter 1: Introduction
Schematic of the variable density tunnel (VDT) (From Baals,

D. D. and Carliss, W. R., Wind Tunnels of NASA, NASA SP-440, 1981).

Wind-tunnel test

Слайд 7

Review
Fluid static dynamics: Buoyance
Consider the forces along y axis: Positive upward,

then—

Hydrostatic equation — differential equation, which connects the pressure variation in fluid with the vertical height.

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Review
Type of flow
Continuum flow
If the orders of magnitude of λ

is smaller than the specific scale of body(such as D) relatively, and then the fluid behaves as a continuous medium. The fluid presents a macro-behaving property, why?
Free molecular flow
If λ is the same order of the specific scale of body，the fluid presents individual molecules’ behaving.
Intermediate state
The flow features are between the above two — “Low density flow”
Most practical aerodynamic applications involve continuum flow.

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Review
Inviscid flow versus Viscous flow
Viscous flow: This transport on a molecular

scale gives rise to the phenomena of mass diffusion, viscosity (friction), and thermal conduction. All real flows exhibit the effects of these transport phenomena, such flows are called viscous flows.

Inviscid flow: Really exists? Inviscid flows do not truly exist in nature.

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Course Diagram

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Chapter 1
Learning Targets

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Chapter 1: Introduction
1.11 Viscous flow: Brief introduction on boundary layer
At any

point in flow field, provided that the velocity gradient exists, the shear stress does also.
Only where the gradients are substantial, has the local stress as a meaningful effect on the flow.
The flow field can be divided into two regimes—

Inside a thin layer adjacent to the body surface, the velocity gradient is large, friction play a definitive/crucial role—Viscous flow (Boundary layer)
In the region outside the thin layer, the gradient is so relatively small that the friction plays nearly no role—Inviscid flow

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Chapter 1: Introduction
In 1904, Prandtl put forward the concept of boundary

layer: boundary layer—the region adjacent to the body surface. Two regions—viscous and inviscid, can be solved respectively.
Flow separation — Pressure distribution will be changed severely—thin, but important
Pressure drag

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Chapter 1: Introduction
Question: Why are the gradients so large inside the

layer?
Inviscid, no friction, the surface is streamline. In fact, adjacent to the surface, the molecules’ velocities are zero—no-slip condition, but the increasing gradient must be?
The boundary layer theory: shear stress τw and layer thickness δ.
Indicated by researches: The pressure is nearly constant along the normal direction to the surface in the layer.

Question: What does the above suggest?
The pressure at the outside edge obtained by inviscid theory has no any change across the layer (the change can be neglected);
The distribution is very close to the real one(very high accuracy);
The above conclusions have preconditions: thin layer and no separation.

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Chapter 1: Introduction
Note: the above two are reasonable for the layer

attached on the surface all the way, but not appropriate for the separated flow shown by Fig.1.43.

Velocity profile inside boundary layer: The curve (vector end curve) of the velocity inside the boundary layer as the function of the normal axis to the local body surface. Function of x.

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Chapter 1: Introduction
Temperature profile through the layer: The curve of the

temperature through the boundary layer as the function of the local normal axis. Dominated by (1) Thermal conduction——heat mixing by molecules random motion; (2) Frictional dissipation——frictional shear stress results in energy conversion(kinetic- internal).
The shear stress on the wall skin is determined by the slope rate of the velocity profile adjacent to the skin:
where, μ is the absolute viscous coefficient (M/LT).

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Chapter 1: Introduction
μ variation with temperature: liquid (olive ; soybean- edible

oil)—T increase, μ decrease; Gas, the contrary. Sea level, standard atmospheric air (right figure: μ= μ(T))
μ=1.7894×10-5kg/(m)(s)
The slope of the temperature profile on the wall indicates whether if the wall is aero-heated or cooled. Aero-heating rate is:
Where, k is the thermal conductivity of the gas. The negative sign ?

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Chapter 1: Introduction
At standard sea level temperature:
k=2.53×10-2J/(m)(s)(K)
Proportional to the viscous

coefficient essentially, i.e
k=(const) ×μ
“Convective heat transfer”: the air flow over a body surface heats or cools the surface(thermal conduction).
“Aerodynamic heating”: the heat transfer between boundary layer and body surface. Dominates the supersonic flow especially hypersonic one.

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Chapter 1: Introduction
Re effect on boundary layer:
Figure below: Development of boundary

layer on plate
Local Reynolds number at x away from the leading edge(characteristic length is x):
“∞” dictates the parameter of the far forward flow relative to plate.
The skin friction(shear stress) and the thickness of boundary layer at x on the plate are the function of Rex .

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Chapter 1: Introduction
The Reynolds number generally governs the nature of the

viscous flow.
The basic types of viscous flow:
Laminar flow: the streamlines are smooth and regular , and the fluid element moves smoothly along the streamline;
Turbulent flow: the streamlines break up and a fluid element moves in a random, irregular and tortuous fashion.

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Chapter 1: Introduction
Fig.1.53: Comparison for the two velocity profiles——
Turbulent, relatively “plump”；
Laminar,

relatively “gradual”.
Approaching to the wall, the gradients of the two flows are different.
The relation of the velocity gradient at the wall:

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Chapter 1: Introduction
By Eq.1.59: (τw)laminer<(τw)turbulent
The important fact: The shear stress

of laminar flow is smaller than turbulent flow !
The types of the wall boundary layer determine the character of the frictional force on the aircraft——the frictional drag produced by laminar flow is smaller relatively!
There is similar result for “aero-heating”: Turbulent flow is larger than laminar flow, even much huge. For hypersonic flow, even up to more than 10 times!

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Chapter 1: Introduction
Homework: 1.11, 1.12
Questions for thinking:
1. After released, the

hydrogen ball will continue to go up, what will happen in the end? Please analyze the reason;
2. Deduce the Pascal law by Hydrostatic equation.

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Chapter 1: Introduction
1.12 Applied aerodynamics: Aerodynamic coefficients——
Magnitudes and variations
Applied aerodynamics:

For the practical evaluation on the aerodynamic properties of aircrafts and design works.
(1) Configuration and performance; (2) Properties of flow field; (3) Components design; (4) Drag reducing design; (5) Type modified design;(6) New conceptual aircraft , etc.

In fact, aerodynamics evaluations run through the whole developing process of aircraft, and are gradually coupled with the analysis for every other subjects(such as structural dynamics or flight dynamics etc.) tightly, in order to solve conceptual design, components design, aero-elastic design, flight quality( maneuverability, stability), structural strength( fatigue lifetime), heath monitor, human factor and other problems.

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Chapter 1: Introduction
Lift, Drag and moment coefficient are the most frequently

used technical terms in outflow aerodynamics.
It is very important to master the magnitude concept of the actual typical values of aerodynamic coefficients.
Question: Is it meaningful for drag coefficient to take the value in [10-5,1000] ?
The order of magnitude of the aerodynamic coefficients for commonly used configurations are listed below.
Question: What are the typical drag coefficients of different aerodynamic configurations?

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Chapter 1: Introduction
Fig.1.54, Typical drag coefficients of some bodies (fixed attitude)

moving in a low speed.
By Sec. 1.7:
CD =f(Re, M∞) , then, CD =f(Re) .
Precondition for simplification ?
Re = ?

Comparisons between Case a, b and c:
Re all are 105, specific lengths d, and the specified areas are S=d·1. From a to c, the wake area shrinks and decreases, while the drag coefficient becomes smaller. CD=2——1.2——0.12.

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Chapter 1: Introduction
Comparisons between Case b and d :
One order

of magnitude difference in both Re and diameter, but CD same, all are 1.2. For cylinders, Re in the domain of 104-105, CD values are relatively not inflected by the Reynolds number.
Value of drag?

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Chapter 1: Introduction
Comparisons between Case c and d :
Same dynamic pressures,

drags are same too; c body a streamline one and height is 10 times of d‘s!
The drag reducing effect of streamline one is significant!

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Chapter 1: Introduction
Comparisons between Case b and e :
Same diameter, but

Ree=100·Reb, and CDe=2·CDb
——the wake is relatively small !(Part4)

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Chapter 1: Introduction
Note：Character parameter(per unit span)—the maximum windward cross-sectional area. The

drag coefficients vary from 2.0 to 0.12. Typical magnitude change.
The Reynolds numbers also change from tens of thousands to tens of millions. At standard sea level, for circle cylinder,
ρ∞= 1.23kg/m3; µ∞ =1.7894×10-5kg/(m)(s) ; V∞ =45m/s; D=1m
then
In practice, the orders of magnitude of usually used Reynolds number in aerospace are from millions to tens of millions .

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Chapter 1: Introduction
Nature of drag: Axial force, Eq.1.8 becomes——
The aerodynamic drag

on any body consists of pressure drag and friction drag .

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Chapter 1: Introduction
Fig.1.55, the comparison for the relative quantities of two

types of drag of the above bodies.
Note：
The drags of upright plate and cylinder are mainly dominated by pressure drag;
The most part of drag of the streamline body is skin friction drag;
ρ∞、μ∞ same, v∞ determined by Re, then v∞ in case e is much larger, and its drag is much larger than in case b.

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Chapter 1: Introduction
Thus, there are two types of typical aerodynamic shapes:
Blunt

body: Most part of drag of the body (the radius of its head is relatively large) are pressure drag;
Streamline body: Most part of drag of the body are skin friction drag;
The drag of blunt body is much larger because its flow separates in its most area.
Pressure drag: The pressure difference drag resulted by the separated flow, also called “shape drag”.

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Chapter 1: Introduction
Variation of the plate drag at zero angle of

attach with the Reynolds number : The drag is totally produced by shear stress, and no any pressure in drag direction.
Skin friction drag coefficient:
Where, the reference area is the plane area per unit span.

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Chapter 1: Introduction
The figure listed above indicates that:
Cf strongly depends on

Re, of which the character length l is the chord length c of the plate. As Re increases, Cf decreases;
Cf value is decided by the flow over the plate whether is laminar or turbulent. With the same Re, the turbulent is larger than the laminar;
Cf The typical magnitude range is from 0.001 to 0.01 in a large Re domain.
The difference relative to upright plate?

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Chapter 1: Introduction
NACA63-210 airfoil：
With thickness, laminar airfoil—low angle—laminar flow—turbulent one

at higher angle, the drag increases quickly. Minimum drag exists(0.0045)—“bottom of pot (barrel)”.
For typical airfoils — 0.004~0.006 (dominated by friction)
For the streamline body — flow separation—pressure drag—the drag coefficient increases with angle.

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Chapter 1: Introduction
The drag on a low speed airplane :

Seversky P-35, the typical fighter in 1930s. Fig.1.58 is the detail drag variation for the aircraft in its design process.
Note: condition 1 is clean aerodynamic configuration, CL=0.15, CD=0.0166. From 2 to 18, conventional and operational changes to equip the plane , all the additions make the drag coefficient increase up to more than 65%, as all are equipped, it reaches to 0.0275, this is the typical value for this type of aircraft.

Слайд 38

Chapter 1: Introduction
Question: As Mach number increases, how will the drag

coefficient change ?
Northrop T-38A jet trainer, see Fig.1.60.
Zero-lift drag coefficient CDL=0 : The corresponding drag coefficient when the lift is just zero for an aircraft at a small angle of attack.
Before the quick increase of the drag, CD≈0.015, lower than that of P35 due to its good aerodynamic shape.（0.86）

Слайд 39

Chapter 1: Introduction
Typical order of magnitude of lift coefficient:
Fig.1.61-NACA63-210 airfoil

‘s lift curve—cl in the range of [-1.0, 1.5], AOA — -12° to +14°.
Lift-to-drag ratio L'/D‘(cl / cd ):
Important index; the ratio —
cl / cd =0.6/0.0046=130（4 °）
To produce enough lift by overcoming drag as little as possible!

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Chapter 1: Introduction
Lift coefficient for full aircraft:
Fig.1.62- CL-α curve for

T38 :
added the influence of the flap deflection angle variation.
Lift to drag ratio for full aircraft:
About 10. More components and the 3D flow effect of wing tip—induced drag(extra pressure drag), thus, much smaller than airfoil. For B-52 boomer, it has its maximum value 21.6.

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Chapter 1: Introduction
The order of magnitude of moment coefficient :
Fig.1.63-cm.c/4

curve for NACA63-210 airfoil. Mainly negative value, magnitude — -0.035 or so, typical one.

Слайд 42

Chapter 1: Introduction
Homework: p1.16、p1.18
Thinking work:
Can all the drag

come down to pressure drag or friction drag from the view of body itself ?

Слайд 43

Chapter 1: Introduction
The key points and difficult points in this chapter
Key

points:
Fundamental aerodynamics variables;
Aerodynamic forces and moments
Pressure center
Similar concepts, theorems, criterion and derived methods
Flow type
Order of magnitudes of aerodynamic forces
Difficult points:
Concept of pressure center
Similar criterion and derived methods

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Chapter 1: Introduction
Summation

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Aerodynamics I

Содержание

Useful Info

ReviewThe Principle of Dimensional Homogeneity (PDH)——a rule which is almost a

ReviewBasic Theorem

ReviewFlow similarityBy definition, different flows are dynamically similar if:The streamline patterns

Chapter 1: IntroductionSchematic of the variable density tunnel (VDT) (From Baals,

ReviewFluid static dynamics: BuoyanceConsider the forces along y axis: Positive upward,

ReviewType of flowContinuum flow If the orders of magnitude of λ

ReviewInviscid flow versus Viscous flowViscous flow: This transport on a molecular

Course Diagram

Chapter 1Learning Targets

Chapter 1: Introduction1.11 Viscous flow: Brief introduction on boundary layerAt any

Chapter 1: IntroductionIn 1904, Prandtl put forward the concept of boundary

Chapter 1: IntroductionQuestion: Why are the gradients so large inside the

Chapter 1: IntroductionNote: the above two are reasonable for the layer

Chapter 1: IntroductionTemperature profile through the layer: The curve of the

Chapter 1: Introductionμ variation with temperature: liquid (olive ; soybean- edible

Chapter 1: IntroductionAt standard sea level temperature: k=2.53×10-2J/(m)(s)(K)Proportional to the viscous

Chapter 1: IntroductionRe effect on boundary layer:Figure below: Development of boundary

Chapter 1: IntroductionThe Reynolds number generally governs the nature of the

Chapter 1: IntroductionFig.1.53: Comparison for the two velocity profiles——Turbulent, relatively “plump”；Laminar,

Chapter 1: IntroductionBy Eq.1.59: (τw)laminer<(τw)turbulent The important fact: The shear stress

Chapter 1: IntroductionHomework: 1.11, 1.12Questions for thinking: 1. After released, the

Chapter 1: Introduction1.12 Applied aerodynamics: Aerodynamic coefficients—— Magnitudes and variationsApplied aerodynamics:

Chapter 1: IntroductionLift, Drag and moment coefficient are the most frequently

Chapter 1: IntroductionFig.1.54, Typical drag coefficients of some bodies (fixed attitude)

Chapter 1: IntroductionComparisons between Case b and d : One order

Chapter 1: IntroductionComparisons between Case c and d :Same dynamic pressures,

Chapter 1: IntroductionComparisons between Case b and e :Same diameter, but

Chapter 1: IntroductionNote：Character parameter(per unit span)—the maximum windward cross-sectional area. The

Chapter 1: IntroductionNature of drag: Axial force, Eq.1.8 becomes——The aerodynamic drag

Chapter 1: IntroductionFig.1.55, the comparison for the relative quantities of two

Chapter 1: IntroductionThus, there are two types of typical aerodynamic shapes:Blunt

Chapter 1: IntroductionVariation of the plate drag at zero angle of

Chapter 1: IntroductionThe figure listed above indicates that:Cf strongly depends on

Chapter 1: IntroductionNACA63-210 airfoil： With thickness, laminar airfoil—low angle—laminar flow—turbulent one

Chapter 1: IntroductionThe drag on a low speed airplane :

Chapter 1: IntroductionQuestion: As Mach number increases, how will the drag

Chapter 1: IntroductionTypical order of magnitude of lift coefficient: Fig.1.61-NACA63-210 airfoil

Chapter 1: IntroductionLift coefficient for full aircraft: Fig.1.62- CL-α curve for

Chapter 1: IntroductionThe order of magnitude of moment coefficient : Fig.1.63-cm.c/4

Chapter 1: IntroductionHomework: p1.16、p1.18 Thinking work: Can all the drag

Chapter 1: IntroductionThe key points and difficult points in this chapterKey

Chapter 1: IntroductionSummation

Chapter 1: IntroductionSummation

Похожие презентации

Review
The Principle of Dimensional Homogeneity (PDH)——a rule which is almost a

Review
Basic Theorem

Review
Flow similarity
By definition, different flows are dynamically similar if:
The streamline patterns

Chapter 1: Introduction
Schematic of the variable density tunnel (VDT) (From Baals,

Review
Fluid static dynamics: Buoyance
Consider the forces along y axis: Positive upward,

Review
Type of flow
Continuum flow
If the orders of magnitude of λ

Review
Inviscid flow versus Viscous flow
Viscous flow: This transport on a molecular

Chapter 1
Learning Targets

Chapter 1: Introduction
1.11 Viscous flow: Brief introduction on boundary layer
At any

Chapter 1: Introduction
In 1904, Prandtl put forward the concept of boundary

Chapter 1: Introduction
Question: Why are the gradients so large inside the

Chapter 1: Introduction
Note: the above two are reasonable for the layer

Chapter 1: Introduction
Temperature profile through the layer: The curve of the

Chapter 1: Introduction
μ variation with temperature: liquid (olive ; soybean- edible

Chapter 1: Introduction
At standard sea level temperature:
k=2.53×10-2J/(m)(s)(K)
Proportional to the viscous

Chapter 1: Introduction
Re effect on boundary layer:
Figure below: Development of boundary

Chapter 1: Introduction
The Reynolds number generally governs the nature of the

Chapter 1: Introduction
Fig.1.53: Comparison for the two velocity profiles——
Turbulent, relatively “plump”；
Laminar,

Chapter 1: Introduction
By Eq.1.59: (τw)laminer<(τw)turbulent
The important fact: The shear stress

Chapter 1: Introduction
Homework: 1.11, 1.12
Questions for thinking:
1. After released, the

Chapter 1: Introduction
1.12 Applied aerodynamics: Aerodynamic coefficients——
Magnitudes and variations
Applied aerodynamics:

Chapter 1: Introduction
Lift, Drag and moment coefficient are the most frequently

Chapter 1: Introduction
Fig.1.54, Typical drag coefficients of some bodies (fixed attitude)

Chapter 1: Introduction
Comparisons between Case b and d :
One order

Chapter 1: Introduction
Comparisons between Case c and d :
Same dynamic pressures,

Chapter 1: Introduction
Comparisons between Case b and e :
Same diameter, but

Chapter 1: Introduction
Note：Character parameter(per unit span)—the maximum windward cross-sectional area. The

Chapter 1: Introduction
Nature of drag: Axial force, Eq.1.8 becomes——
The aerodynamic drag

Chapter 1: Introduction
Fig.1.55, the comparison for the relative quantities of two

Chapter 1: Introduction
Thus, there are two types of typical aerodynamic shapes:
Blunt

Chapter 1: Introduction
Variation of the plate drag at zero angle of

Chapter 1: Introduction
The figure listed above indicates that:
Cf strongly depends on

Chapter 1: Introduction
NACA63-210 airfoil：
With thickness, laminar airfoil—low angle—laminar flow—turbulent one

Chapter 1: Introduction
The drag on a low speed airplane :

Chapter 1: Introduction
Question: As Mach number increases, how will the drag

Chapter 1: Introduction
Typical order of magnitude of lift coefficient:
Fig.1.61-NACA63-210 airfoil

Chapter 1: Introduction
Lift coefficient for full aircraft:
Fig.1.62- CL-α curve for

Chapter 1: Introduction
The order of magnitude of moment coefficient :
Fig.1.63-cm.c/4

Chapter 1: Introduction
Homework: p1.16、p1.18
Thinking work:
Can all the drag

Chapter 1: Introduction
The key points and difficult points in this chapter
Key

Chapter 1: Introduction
Summation

Chapter 1: Introduction
Summation