electromagnetic propulsion system (launcher)

Abstract:

            Ever since John Munro published his fictional story, “A trip to Venus” in 1897 people started dreaming of propulsion without any engines. Thus, resulting concept of electromagnetic propulsion system. 

at 10th national technology compition 2013 (LOCUS)

Electromagnetic propulsion (EMP), is the principle of accelerating an object by the utilization flowing electrical current and magnetic fields. With the help of electromagnetic propulsion system, many modern days marvels such as maglev trains and different accelerators have been made. thus with the principle of electromagnetic accelerators we created a coil gun that can shoot paramagnetic or ferromagnetic substance. 

Recent advances in energy storage, switching and magnet technology make electromagnetic propulsion a viable alternative to chemical propulsion for certain tasks, and a mean to perform other tasks not previously feasible. Launchers of interest include the dc rail gun driven by energy stored initially in a homopolar generator and transferred through a switching inductor, and the opposite extreme, the synchronous mass driver energized by a high voltage alternator through an oscillating coil-capacitor circuit. A number of hybrid variants between these two extremes are also promising. A novel system described here is the momentum transformer which transfers momentum from a massive chemically driven armature to a much lighter, higher velocity projectile by magnetic flux compression. Potential applications include the acceleration of gram-size particles for hypervelocity research and for use as reaction engines in space transport; high velocity artillery; stretcher-size tactical supply and medical evacuation vehicles; the launching of space cargo or nuclear waste in one-ton packets using off-peak electric power.

The Launcher is a device which helps to launch the things in the air with varying range and velocity. It makes daily work easy. It is a mobile device which can hurl things in desired trajectory. The desired trajectory, launching velocity as well as time duration of the flight is controlled by a computer. The prototype version that we created and were successful is captured ABOVE in the pictures:

Background theory:

           The launcher is based on two main principles that ar:

 Electric gun theory

 Projectile motion

Materials required:

1. Copper coils.
2. A.C. voltage source and D.C. voltage source.
3. Step up and step down transformers.
4.  Jumping Wire
5. Solder
6. Nail or similar small, magnetic object.
7. Hot glue
8. Resistors, diode, transistors, relay, etc.
9. Avr atmega32 microcontroller.
10. Long projectile pipe.
11. Mechanical tools such a screw and drills.
12. Motor and wooden or metal framework.
13. Motor driver L293D or L298 

    

    schematics of launcher circuit.

    
    

    

    preciew of the circuit board before being etched

Tips

• If your wrapping your own coil, make sure you have about maximum turns for effective magnetic field.
• Try varying the distance of the loaded projectile to the coil
• Be precise while calculating the time intervals for coding in microcontroller.
• Don’t leave any naked wires which are accessible to any person.

Application of this device:

•  Small coilguns are recreationally made by hobbyists, typically up to several joules to tens of joules projectile energy (the latter comparable muzzle energy to a typical air gun and an order of magnitude less than a firearm) while ranging from under one percent to several percent efficiency.
•             Much higher efficiency and energy can be obtained with designs of greater expense and sophistication. In 1978, Bondaletov in the USSR achieved record acceleration with a single stage by sending a 2-gram ring to 5000 m/s in 1 cm of length, but the most efficient modern designs tend to involve many stages. Above 90% efficiency is estimated for some vastly larger superconducting concepts for space launch. An experimental 45-stage DARPA coilgun mortar design is 22% efficient, with 1.6 megajoules KE delivered to a round.
•             Though facing the challenge of competitiveness versus conventional guns (and sometimes railgun alternatives), coilguns are being researched for weaponry.
•               The DARPA Electromagnetic Mortar program is an example of potential benefits, if practical challenges like sufficiently low weight can be managed. The coilgun would be relatively silent with no smoke giving away its position, though a coilgun projectile would still create a sonic boom if supersonic. Adjustable yet smooth acceleration of the projectile throughout the barrel can allow somewhat higher velocity, with a predicted range increase of 30% for a 120mm EM mortar over the conventional version of similar length. With no separate propellant charges to load, the researchers envision the firing rate to approximately double.
•                In 2006, a 120mm prototype was under construction for evaluation, though time before reaching field deployment, if such occurs, was estimated then as 5 to 10+ years by Sandia National Laboratories. In 2011, development was proposed of an 81mm coilgun mortar to operate with a hybrid-electric version of the future Joint Light Tactical Vehicle.
•               Electromagnetic aircraft catapults are planned, including on board future U.S. Gerald R. Ford class aircraft carriers. An experimental induction coilgun version of an Electromagnetic Missile Launcher (EMML) has been tested for launching Tomahawk missiles. A coilgun-based active defense system for tanks is under development at HIT in China.
•            Coilgun potential has been perceived as extending beyond military applications. Challenging and corresponding to a magnitude of capital investment that few entities could readily fund, gigantic coilguns with projectile mass and velocity on the scale of gigajoules of kinetic energy (as opposed to megajoules or less) have not been developed so far, but such have been proposed as launchers from the Moon or from Earth:

• An ambitious lunar-base proposal considered within a 1975 NASA study would have involved a 4000 ton coilgun sending 10 million tons of lunar material to L5 in support of massive space colonization (cumulatively over years, utilizing a large 9900-ton power plant).
• A 1992 NASA study calculated that a 330-ton lunar superconducting quenchgun could launch annually 4400 projectiles, each 1.5 tons and mostly liquid oxygen payload, using a relatively small amount of power, 350 kW average.
• After NASA Ames estimated how to meet aerothermal requirements for heat shields with terrestrial surface launch, Sandia National Laboratories investigated electromagnetic launchers to orbit, in addition to researching other EML applications, both railguns and coilguns. In 1990, a kilometer-long coilgun was proposed for launch of small satellites.
•        Later investigations at Sandia included a 2005 study of the StarTram concept for an extremely long coilgun, one version conceived as launching passengers to orbit with survivable acceleration.