Aerodynamics of a Rocket

8/14/2019 Aerodynamics of a Rocket

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Aerodynamics of a RocketAerodynamics of a Rocket

Mentor: A/P Andrew WeeMentor: A/P Andrew Wee

Group Members:Group Members:

Darwin GosalDarwin Gosal

Martin LeeMartin Lee

Tan Hai SiongTan Hai Siong

Tan Kim SengTan Kim Seng


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OutlineOutline

s IntroductionIntroduction

sTheoretical BackgroundTheoretical Background

s Procedure / Set UpProcedure / Set Up

s Results and AnalysisResults and Analysis

s

ConclusionConclusions ImprovementsImprovements

s Further ExperimentFurther Experiment


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IntroductioIntroductio

nn

These fin shapes with angleThese fin shapes with angle varying from 45 tovarying from 45 to9090(in increasing steps of 5)(in increasing steps of 5) will be inserted onto thewill be inserted onto therocket body shaft during the experiment. A wind tunnelrocket body shaft during the experiment. A wind tunnel

will be used to channel moving air currents upwardwill be used to channel moving air currents upwardtowards the rocket body. An empirical relation betweentowards the rocket body. An empirical relation betweenthe resulting drag force and the anglethe resulting drag force and the angle would bewould beobtained from the experimental results. Theobtained from the experimental results. Theinterdependence between the wind speed with theseinterdependence between the wind speed with these

two variables was investigated.two variables was investigated.


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IntroductioIntroductio

nn

ROCKET BODY


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s Viscous DragViscous Drag :-:- drag due to skindrag due to skinfrictionfriction

s Form DragForm Drag :-:- drag due to thedrag due to the

separation of the flow from the bodyseparation of the flow from the bodywhich results in the alteration ofwhich results in the alteration of

pressure distribution.pressure distribution.

TheoreticalTheoretical

BackgroundBackground


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s The expressions for the coefficient ofThe expressions for the coefficient of

viscosityviscosity and the shearing stressand the shearing stress ininterms of the properties of the fluid & of theterms of the properties of the fluid & of theflow are:flow are:

s = 1/3= 1/3 c Lc Ls == u /u / yy




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sThe concept of a shearing stress is:The concept of a shearing stress is:

Rate of transfer of downstreamRate of transfer of downstream

momentum in a direction lateral tomomentum in a direction lateral tothe flow.the flow.

sThe shearing stress at the surface :The shearing stress at the surface :==

u /u /

yy

is the skinis the skin

friction (friction (Force per unit areaForce per unit area.).)

sThis is exerted by the fluid on theThis is exerted by the fluid on the

surface in the tangential direction.surface in the tangential direction.




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1. Eulers Equation may be written as:

2. After summing up the pressure and shear forces on an

element in a boundary layer : -

3. We thus obtain the boundary layer equation of motion:




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4. The continuity equation for incompressible flow :-

5. The boundary layer equation of

motion and the continuity equation are

the equations available for the solution ofour aerodynamic problem.




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Figure 3.3: - Boundary Layer on aflat plate

y

Ue

y= 1. For the steady flow of theincompressible viscous fluid

along a flat plate:

2. Upon solving these differential

equations, we obtained an expressionfor the drag force:

drag per unit area =

where ue

is the speed of wind of the wind tunnel

as measured by the anemometer.

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24

1

vx

uuA

e

e




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Procedure / SetProcedure / Set

UpUp

F2F3

Wind Tunnel

F1

Rocket Body with Fins

Balance Pan with Standard

Weights

Voltmeter

Force

Transducer

Lever

pivot

Pulley

Connecting

Wires

Anemometer


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Results &Results &

AnalysisAnalysis

F1 vs wind speed

0.0025

0.003

0.0035

0.004

0.0045

0.005

0.0055

0.006

0.0065

0.007

7 7.5 8 8.5 9 9.5 10 10.5 11

Wind speed (m/s)

F1

(

45

50

55

60

65

70

75

80

85

90


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Results &Results &

AnalysisAnalysis

Grap

hs

Velocity of

wind(m/s)

Total increase

(10-4N)

Gradient of Regression

line (10-5 N degree-1)

A 7 3.72780 1.390

B 8 5.54694 1.909

C 9 8.91686 2.736

D 10 10.1992 3.029

E 11 20.8160 4.718


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Results &Results &

AnalysisAnalysis

Graph A : V=7m/s

y = 0.0000139x + 0.0025471

0

0.0005

0.001

0.0015

0.002

0.0025

0.003

0.0035

0.004

0.0045

40 45 50 55 60 65 70 75 80 85 90 95

Angle

F1


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Results &Results &

AnalysisAnalysis

Graph B : V=8m/s

y = 0.00001909x + 0.00252356

0

0.0005

0.001

0.0015

0.002

0.0025

0.003

0.0035

0.004

0.0045

40 45 50 55 60 65 70 75 80 85 90 95

Angle

F1


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Results &Results &

AnalysisAnalysis

Graph C : V=9m/s

y = 0.0000273592x + 0.0023886791

0

0.001

0.002

0.003

0.004

0.005

0.006

40 45 50 55 60 65 70 75 80 85 90 95

Angle

F1


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Results &Results &

AnalysisAnalysis

Graph D : V=10m/s

y = 0.00003029x + 0.00267907

0

0.001

0.002

0.003

0.004

0.005

0.006

40 45 50 55 60 65 70 75 80 85 90 95

Angle

F1


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Results &Results &

AnalysisAnalysis

Graph E (V=11m/s)

y = 0.00004718x + 0.00221553

0

0.001

0.002

0.003

0.004

0.005

0.006

0.007

40 45 50 55 60 65 70 75 80 85 90 95

Angle

F1


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Results &Results &

AnalysisAnalysis

Graph Angle (degrees) Gradient of Regression Line (N m-1 s)

F 45 0.000326

G 50 0.000270

H 55 0.000500

I 60 0.000429

J 65 0.000310

K 70 0.000515

L 75 0.000577

M 80 0.000516

N 85 0.000584

O 90 0.000715


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ConclusionConclusion

..

s There is a clear, direct relationshipThere is a clear, direct relationship

between resistive force and thebetween resistive force and the

variables and furthermore more that itvariables and furthermore more that itis an increasing function of both ofis an increasing function of both of

them.them.

s It has also been observed that withIt has also been observed that with

higher wind speed, the resistive forcehigher wind speed, the resistive forceincreases more quickly with increasingincreases more quickly with increasing

angles.angles.


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Problems &Problems &

ImprovementsImprovements


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FurtherFurther

ExperimentExperiment

P

Rocket

Fishing linesconnected to

the 4 corners

of the frame.

Frame to be

secured to

retort stand.


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Wind

Tunnel

PART A

PulleyFishing

Line

Force

Transducer

Voltmeter

FurtherFurther



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Slack

String

Original

Position

Force F

acting

on string

To Force

transducer

Note that because of

4 taut strings holding

the rocket to the

frame, the rocket canonly turn in the frame

but cannot move up

or down in the frame.

FurtherFurther



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Upward forceacting on the

force

transducers rod.

Force transducer

FurtherFurther



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THE END


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Weight BalanceWeight Balance


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PulleyPulley


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AnemometerAnemometer


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Rocket BodyRocket Body


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Force TransducerForce Transducer


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Wind TunnelWind Tunnel


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PivotPivot


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Aerodynamics of a Rocket

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