Introduction to high power rocketry

Dr. Adam M Baker

Summary

1. How does HPR differ from model rocketry?2. Some design guidelines for HPR3. Something on payloads4. Examples of HPR

• Still images... Videos...HARDWARE!5. Amateur rocketry

www.ukra.org.uk

HPR v. Model rockets (1)

HPR v. Model rockets (2)• ESTES • Aerotech K550W

Total Impulse 1595 (Ns) Maximum Thrust 845 (N) Average Thrust 467 (N) Burn Time 3.42 (s) Loaded Mass 1.51 (kg) Propellant Mass 0.88 (kg)

Total Impulse 5 (Ns) Maximum Thrust 12 (N) Average Thrust 6 (N) Burn Time 0.85 (s) Loaded Mass 0.018 (kg) Propellant Mass 0.065 (kg)

HPR v. Model rockets (3)

HPR v. Model rockets (4)

• Models– Paper– Balsa– Plastic

• HPR– Metals e.g. Aluminium– CFRP– Phenolic tubing

HPR v. Model rockets (5)

• Mass, Size• Motors• Trajectory• Materials, components

SAFETY

Where can I get help?

• UK Rocketry Association• www.ukra.org.uk• Rules, regs , lots of

‘experts’• ESSENTIAL for launch

• Rockets ‘n’ Things– Malcolm Jennings

• Main supplier in Southern England for HPR parts

• www.rocketsandthings.com

Guidelines

For HPR design

Stability (1)

– Defined by Barrowman equations

– Cp v. Cg, or – ‘Static margin’

http://my.execpc.com/~culp/rockets/Barrowman.htmlhttp://www.apogeerockets.com/downloads/pdfs/barrowman_report.pdf

Stability (2)

• Barrowman– Slender body theory

1. (L/D) between 10 and 35

2. 15 < CN <303. Subsonic flight. 4. ‘Thin’ cross-section fins.

• Velocity– Min 20m/s for fins to act– Or 50m/s2 acceleration

(4m launch tower / rail)Þ6:1 T:W on launch

• Static stability margin- 1.5-2.5 calibres

CENTREOF

MASS

CENTREOF

PRESSURE

1.5D<STATIC MARGIN<2.5D

L

D

Launch ramp / tower / rail

Motor mountingTotal Impulse 1595 (Ns) Maximum Thrust 845 (N) Average Thrust 467 (N) Burn Time 3.42 (s) Loaded Mass 1.51 (kg) Propellant Mass 0.88 (kg)

NUT

FIREWALL

MOTOR CASE

FORWARD BULKHEAD

CLAMP1.2.

FIN

MOTOR THRUST RING

Structure2° MAX LONGITUDINALAXIS

TEST FORCE=2 x FIN MASS x MAX ACCELERATION

d

LAUNCH WEIGHT OF ROCKET

S

d < S x tan 10°

z

x

Z/X< 1%

CENTREOF MASS

Fin alignment

Fin Long. loading

Fin Lat. loading

Structure (2)

• Coupling sections of rocket

METAL

PLASTICSor

COMPOSITE

CONNECTING BODY TUBES

1/2 D

D

D

Recovery

Recovery (2)

• Redundancy

• Test Test Test!

• Tracking

HPR Payloads

Payloads (1)

• Accelerometer / altimeter– E.g.

• G-Wiz• P-Nut

• Flight computer– E.g. R-DAS

http://www.aedelectronics.nl/rdas/

Credit: Richard Osborne

Payloads (2)

• Altimeter / recovery • Cameras

Credit: Richard Osborne

‘GoPro.com’ video cameras

Payloads (3)Credit: Richard Osborne

Examples of HPR

AspireSpace, ASRV-1aThetford1997K-class motor , 1250Ns2.1m long, 100mm diam.5000ft apogee

BURTBristol Uni Rocket Team1999NRC runner-up

2000Teams from • Manchester (UMIST)• Kent• Kingston

M.A.R.S.

2000

USA

25,000ft, aUK record

‘Amateur’ rocketry

AspireSpace, Comer (Scotland) & Lincs2001, 2002

Garvey Aerospace www.garvspace.comMojave, USA, 2005

Flometrics / San Siego State Universitywww.flometrics.com Mojave, USA, 2005

Recap

1. How does HPR differ from model rocketry?2. Some design guidelines for HPR3. Something on payloads4. Examples of HPR

• Still images... Videos...HARDWARE!5. Amateur rocketry6. Who can help?

– www.ukra.org.uk

October 28th, 2021