boost glider design

7/27/2019 Boost Glider Design

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Illinois Aerospace InstituteUniversity of Illinois

SpaceSpaceGrantGrant

Boost Glider Design

Illinois Aerospace Institute

Department of Aeronautical and

Astronautical Engineering

University of Illinois


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Illinois Aerospace InstituteUniversity of Illinois

SpaceSpaceGrantGrant

Boost Glider Design

Introduction

What are we trying to do?

Maximize Endurance

Important Factors to Consider

Balance

Wing area

Glide Slope

Speed


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Illinois Aerospace InstituteUniversity of Illinois SpaceSpaceGrantGrant

Boost Glider Design

Forces

Lift always acts perpendicular to the direction of flight.

Drag always acts parallel to the direction of flight. Weight always acts towards the ground, regardless of

the the direction of flight


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Boost Glider Design

Stability

Stability is the Balancing of Forces

Which hopefully your plane will do naturally

Stability in the Boost phase

Center of Gravity (CG) must be above forward of the

wing Center of Pressure (CP).

Stability in the Glide phase

CG must be behind of the wing CP


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Boost Glider Design

Boost Phase

Thrust counter acts gravity and drag to make the

aircraft climb

Lift from the wing and tail counteract the momentfrom the rocket engine


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Boost Glider Design

Boost Phase


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Boost Glider Design

Wings

Reasons to have a small wing

Lower drag and weight

Will go higher and require as shallower glide angle

Better Boost performance (High Wing Loading)

Wing loading is the ratio of total weight to wing area

Higher Aspect Ratio (AR) for a given area

AR is the ratio of the wing span (b) squared to the total wing

area (S)S

bAR

2

=


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Boost Glider Design

Wings

Reasons to have a large wing

Slower glide speed

Will result in increased the glide time

For given span, higher strength for Boost phase

Will prevent wing shear, which in general is not a goodidea if you plan on gliding for longer than it takes to fall

out of the air


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Boost Glider Design

Glide Phase

A component of the weight is used to overcome

drag

Lift is used to balance the remaining weight


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Boost Glider Design

Stability

Roll Stability (Dihedral)

15~30 degrees

Yaw Stability

Vertical Stabilizer (tail)


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Boost Glider Design

Stability

Pitch Stability

PitchingMo

ment

Weight of glider

Neutral Point

Lift of

Stabilizer

Lift ofWing


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Boost Glider Design

Stability

Tail Heavy (CG to far aft)

Nose Heavy (CG to far forward)


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Boost Glider Design

The Generic Glider


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Boost Glider Design

What do all those letters mean?


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Boost Glider Design

What do all those letters mean?


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Boost Glider Design

So, how should I build this?

Fill out your sheets

Cut your pieces

Sand

Remember to check the

design constraints with

your results

No BLOOD!

Bevel the root chords ofyour wings for good

dihedral joint

Dont worry too muchabout the airfoil shape of

your wing

Building Steps Building Tips


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Boost Glider Design

So, how should I build this?

Assemble the fuselage

Balance glider with clay

Test flights

Dont glue you fingers

together (too many times)

Boost portion first

Tail next

Wings LAST (check your

CG locations)

The less the better

Dont break it

Building Steps Building Tips


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Boost Glider Design

Layout Wing on Balsa


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Boost Glider Design

Layout Tail on Balsa


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Boost Glider Design

Layout Pieces


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University of Illinois SpaceSpaceGrantGrant

Boost Glider Design

Assemble Nose


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Boost Glider Design

Assemble Tail


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Boost Glider Design

Assemble Fuselage


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Boost Glider Design

Assemble Wing

S/2*sin DA*2

boost glider design

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