Rockets and how they work By JanErik Rnningen

Rockets and how they work By Jan-Erik Rønningen Norwegian Rocket Technology [ contact@rocketconsult. no ] [ www. rocketconsult. no ] Version: 1. 30 2008

Contents o o o Rocket history Rocket Principle Fundamental Rocket Elements The Solid Propellant Rocket The Liquid Propellant Rocket The Hybrid Rocket Motor

Rocket History 1 o The Chinese is claimed by many to be the inventor of the black powder (about 200 B. C) and thus the rockets o Newer findings indicate that it is India that should be honored instead o However, old Chinese documents describe long tradition in making various black powder charges for use in firecrackers and rockets mostly for frighten bad spirits during religious happenings and during various festivals and celebrations. o The Chinese also developed rockets and flame torches to be used in combat against their main enemy, the Mongols.

Rocket History 2 o The Arabs learned the art of rocketry from the Mongols and the Europeans from the Arabs. o The Europeans developed the rocket technology further, i. e. between the 14 th and 16 th century: n n n A English munch named Roger Beacon improved the black powder prescription for use as rocket propellant, fire crackers and for use in canons. A French man improved the hit accuracy of his artillery rockets by launching them from tubes. An Italian (Fontana) experimented with rocket powered surface torpedoes which could ran into the cavalry or set ships on fire. One successfully did!!

Rocket History 3 o The interest of the rocket as a weapon went into a hibernation during the 17 th century, mainly because of the poor accuracy compare to the more accurate and destructive canon. Further improvements were necessary. o A new dawn of rocketry appeared during the 18 th century and especially some hundred years after Sir Isacc Newton had published his famous three laws. o During the 19 th and 20 th century many men were to become well know: Ziolkowsky, Hermann Oberth, Robert H. Goddard, Eugen Sänger, Werner von Braun, Korolev and many more

Rocket History 4 o After the WWII the race for space between USA and former Soviet escalated and accelerated the development of rocket technology to what we know and use today. Apollo 11 and Neil Armstrong – First man on the Moon 20. July 1969 Sputnik I – World first artificial satellite launched 4. October 1957 Vostok 1 and Yuri A, Gagarin – First man in space 12. April 1961

The Rocket Principle 1 Newtons 2. law: Newtons 3. law: force = opposite force

The Rocket Principle 2 o A chemical rocket is a reaction device that brings with itself the oxygen needed for combustion and thus for generating thrust for positive propulsion

Rocket Elements – Main Parts c Vc F c : chamber i : entrance t : throat e : exit V: velocity i t Vt e Convergent Divergent section Ve

Rocket Elements - Thrust Ambient Pressure Exit Pressure F Ambient Pressure

Rocket Elements - Nozzle Flow

Rocket Elements - Nozzle Flow Entrance Throat Exit Pe<Pa (over expansion) Pe=Pa (optimum expantion) M~0 P=Pk Subsonic M=1 Ph~0. 5 Pk Transonic M>3 Pe Pe>Pa Supersonic (under expansion)

Rocket Elements - Nozzle Flow

Rocket Elements - Total Impulse

Static Firing a Rocket Motor NSR 30 k. N Hybrid Rocket Motor, 20 s test

Rocket Elements - Specific Impulse

The Solid Propellant Rocket Construction: Motor Case Igniter Thermal Insulation Propellant Nozzle

Solid Propellant Rocket PARAMETER CHARACTERISTIC VALUE RANGE Specific Impulse [m/s] 2000 -2600 Burn rate [mm/s] 1 -15 Chamber Pressure [MPa] 7 -20 Combustion Efficiency [-] 0. 95 -0. 98 Thrust to Weight Ratio High Throttle? Difficult Stop and Restart? Not Practical Lifetime? Long (7 to 15 years)

The Solid Propellant Rocket Propellant Mixing: 300 gallon approx. 1200 kg of propellant

The Solid Propellant Rocket Propellant Grain Geometry:

Advanced Grain Burn Evolution

The Solid Propellant Rocket Ariane 5 Solid Rocket Booster: DATA for one SRB Propellant: HTPB Propellant Mass: 237 T (158 cars) Motor Mass: 273 T (182 cars) Thrust: 5400 k. N (about 550 T!!!!) Burn Time: 130 s (2. 16 min) Mass Consumption: 1. 82 T/s TVC: +/-6 deg vectorable nozzle

The Liquid Propellant Rocket Constructions:

The Liquid Propellant Rocket PARAMETER CHARACTERISTIC VALUE RANGE Specific Impulse [m/s] 2500 -3800 Burn Rate [mm/s] N. A Chamber Pressure [MPa] 2 -10 Combustion Efficiency [-] 0. 95 -0. 98 Thrust to Weight Ratio Low Throttle? Easy Stop and Restart? Easy Lifetime? Very Long (> 10 years)

The Liquid Propellant Rocket

The Hybrid Rocket Start/stop Valve and pressure Injector regulator Check Valve Flow Valve and Regulator with control electronics Solid Grain “Mixing” Zone Liquid Valve Electronics Pressurized Nitrogen or Helium Combustion Chamber Nozzle

The Hybrid Rocket PARAMETER CHARACTERISTIC VALUE RANGE Specific Impulse [m/s] 2100 -3200 Regression rate [mm/s] 0. 2 -5 Chamber Pressure [MPa] 2 -5 Combustion Efficiency [-] 0. 90 -0. 95 Thrust to Weight Ratio Medium Throttle? Easy Stop and Restart? Easy Lifetime? Very Long (>10 years)

The Hybrid Rocket Combustion Principle – The Candle Light Gas (H, C) Liquid Air Paraffin Wax

The Hybrid Rocket

How is it to work as an “rocket scientist”?