Rocket Propulsion

Types of Propulsion Systems Presentation Name Course Name Unit # – Lesson #.# – Lesson Name Types of Propulsion Systems All propulsion systems are driven by an engine Propeller Turbine (also called jet) Ramjet and Scramjet Rocket

Rocket Propulsion Produces thrust by ejecting stored matter Presentation Name Course Name Unit # – Lesson #.# – Lesson Name Rocket Propulsion Produces thrust by ejecting stored matter Rockets can be classified by propulsion Liquid Solid Electric Other classifications Expendable or reusable Number of stages Size of payload Manned or unmanned Rockets store their propellants onboard so they function in the vacuum of space where there is little air. Liquid and solid fuel rockets store fuel in the rocket then oxidize (burn) their fuel to produce high pressure gases which create rocket thrust when vented out the end of the rocket. Exhaust and heat are byproducts of the oxidization. Electric propulsion uses a power supply to expel ionized particles. More information is available from NASA website: http://www.nasa.gov/worldbook/rocket_worldbook.html

Liquid Fuel Rocket Fuel mixed with oxidizer and burned Presentation Name Course Name Unit # – Lesson #.# – Lesson Name Liquid Fuel Rocket Fuel mixed with oxidizer and burned Gases escape out nozzle to generate thrust The propellants shown could be liquid oxygen and kerosene. Both are combined and burned in a combustion chamber to produce rapidly expanding gases. These gases are vented through the throat and allowed to expand in the nozzle. This creates thrust to move the rocket forward. c

Solid Fuel Rocket Fuel burned to generate gases Presentation Name Course Name Unit # – Lesson #.# – Lesson Name Solid Fuel Rocket Fuel burned to generate gases Gases escape out nozzle to generate thrust Fuel stored in the rocket is oxidized, burned, to produce high pressure gases which create rocket thrust when vented out the end of the rocket. The solid propellant consists of grains. The propellant is initiated and burns smoothly expanding the combustion chamber until all the propellant is consumed. As the propellant is burned it releases gases that escape to the nozzle generating thrust to move the rocket forward. The thrust equation shown will be addressed later in this presentation.

Thrust Equation Derivation Presentation Name Course Name Unit # – Lesson #.# – Lesson Name Thrust Equation Derivation Force is generated by ejecting gases. More information about the thrust equation and its derivation can be found at the NASA website: http://www.grc.nasa.gov/WWW/K-12/airplane/topics.htm .

Impulse Equation Derivation Presentation Name Course Name Unit # – Lesson #.# – Lesson Name Impulse Equation Derivation More information about the thrust equation and its derivation can be found at the NASA website: http://www.grc.nasa.gov/WWW/K-12/airplane/topics.htm.

Model Rocket Flight Stages Presentation Name Course Name Unit # – Lesson #.# – Lesson Name Model Rocket Flight Stages Explain the various steps of the rocket flight. Play the two videos (L2_2_Rocket_Video_Ground and L2_2_Rocket_Video_Onboard) located in the support resources. These videos will show a model rocket launch from the ground view and onboard the rocket. Flying model rockets is a relatively safe and inexpensive way for students to learn the basics of forces and the response of vehicles to external forces. Like an airplane in flight, a model rocket is subjected to the forces of weight, thrust, and the aerodynamic forces, lift and drag. The relative magnitude and direction of the forces determines the flight trajectory of the rocket. On this slide we show the events in the flight of a single stage model rocket. Throughout the flight, the weight of a model rocket is fairly constant; only a small amount of solid propellant is burned relative to the weight of the rest of the rocket. This is very different from full scale rockets in which the propellant weight is a large portion of the vehicle weight. At launch , the thrust of the rocket engine is greater than the weight of the rocket and the net force accelerates the rocket away from the pad. Unlike full scale rockets, model rockets rely on aerodynamics for stability. During launch, the velocity is too small to provide sufficient stability, so a launch rail is used. Leaving the pad, the rocket begins a powered ascent. Thrust is still greater than weight, and the aerodynamic forces of lift and drag now act on the rocket. When the rocket runs out of fuel, it enters a coasting flight. The vehicle slows down under the action of the weight and drag since there is no longer any thrust present. The rocket eventually reaches some maximum altitude which you can measure using some simple length and angle measurements and trigonometry. The rocket then begins to fall back to earth under the power of gravity. While the rocket has been coasting, a delay "charge" has been slowly burning in the rocket engine. It produces no thrust, but may produce a small streamer of smoke which makes the rocket more easily visible from the ground. At the end of the delay charge, an ejection charge is ignited which pressurizes the body tube, blows the nose cap off, and deploys the parachute. The rocket then begins a slow descent under parachute to a recovery. The forces at work here are the weight of the vehicle and the drag of the parachute. After recovering the rocket, you can replace the engine and fly again. On the graphic, we show the flight path as a large arc through the sky. Ideally, the flight path would be straight up and down; this provides the highest maximum altitude. But model rockets often turn into the wind during powered flight because of an effect called weather cocking. The effect is the result of aerodynamic forces on the rocket and cause the maximum altitude to be slightly less than the optimum.

Model Rocket Engine Design Presentation Name Course Name Unit # – Lesson #.# – Lesson Name Model Rocket Engine Design Explain the engine components then show the engine ignition animation.

Model Rocket Engine Performance Presentation Name Course Name Unit # – Lesson #.# – Lesson Name Model Rocket Engine Performance B6-4 Performance data shown.

Model Rocket Engine Nomenclature Total impulse Code Delay Time (Seconds) B6-4 Average Thrust (Newtons)

References National Aeronautics and Space Administration (2010). Retrieved from http://www.grc.nasa.gov/WWW/K-12/airplane/topics.htm National Aeronautics and Space Administration (2010). Retrieved from http://www.nasa.gov/worldbook/rocket_worldbook.html Lockheed Martin (2010). Retrieved from http://www.flickr.com/photos/lockheedmartin Reproduction Masters for Model Rocketry, Estes (2010). Retrieved from http://www.estesrockets.com/index.php/site/estes-educator/

References Sutton, G, & Biblarz, O. (2001). Rocket propulsion elements: an introduction to the engineering of rockets. New York, NY: John Wiley & Sons, Inc.