Event

Gear up, propel your imagination, and fire your thoughts... Register yourself in the extraordinary league of rocket scientists... Prakshepan is the annual rocketry event at Conscientia, where budding engineers can wet their hands on true rocket science. This year, build your own water rocket, a humble beginning to start with.

Format

Preliminary Round
The objective will be to launch a water-rocket without a payload, and make it go as far as possible from the launch point. The rocket has to achieve a minimum range of 30m. Multi-stage rockets are also allowed.

Final Round
The teams qualifying the preliminary round will be provided with a payload. They will be required to launch the rocket with the given payload and recover it safely. The provided payload has to be recovered without any damage using a suitable recovery system. The payload maybe a delicate thing (e.g. an egg) so participants are advised to keep this in mind while designing the recovery module. The maximum dimension of the payload will not be more than the size of an egg. Participants may use mechanical as well as electronic recovery modules.

Rules and Regulations

• A team may consist of a maximum of 3 members.
• The rocket must be built completely from scratch using materials which are not manufactured for model rocket parts.
• The pressure vessel must be made from commercially available non-metallic soda bottles that can withstand a pressure of 150-200 psi. Fins, if required, are to be constructed from lightweight non-metallic materials.
• All parts of the water rocket must be attached properly. If any part (fins, etc.) are broken apart during flight, it will compromise the safety of the spectators. Therefore, such water rockets may be disqualified at the discretion of the organisers.
• Each team is strongly advised to bring two rockets of the same design (the second acting as a backup). The organisers will not be responsible for damage inflicted to rockets during the competition.
• Teams may use different rockets for different rounds.
• The rocket must use tap water or soda as its primary reaction mass.
• Thrust must come from expelling reaction mass, not from air discharge.
• Water/soda Reaction Mass must fill a minimum of 20% of the volume of the Pressure Vessel.
• Reaction mass must contain minimum of 20% of water.
• Participants will be provided with tap water, but the have to get their own soda (if they wish to use it).
• The rocket must use compressed ambient atmospheric air as its energy source. A bicycle pump will be provided to compress the air. The size of the outlet of the pump will be compatible with that of the bottle mentioned in above. If your design has a different nozzle size, please be sure to bring your own connecting pipes.

Eligibility
Open to all college students with valid ID cards.

Judgement and Evaluation

Preliminary Round
The qualifying criteria in the qualifying round will be the maximum horizontal range. Each team will be allowed to fire the rocket twice and best of the two performances will be selected for evaluation.

Final Round
The recovery of the payload will be given utmost importance, after which the horizontal range will decide the winner.The participant will be disqualified if the payload is not recovered safely. The scoring will be done as follows:
Score = 4*(the horizontal range of rocket in meters)

Resources

Introduction
A water rocket is a type of model rocket using water as its reaction mass. The pressure vessel — the engine of the rocket — is usually a used plastic soft drink bottle. The water is forced out by a pressurized gas, typically compressed air. Water rocket engines are most commonly used to drive model rockets, but have also been used in model boats, cars, and rocket-assisted gliders.

Operation

• The bottle is mostly filled with water and sealed.
• The bottle is then pressurized with a gas, usually air compressed from a bicycle pump. Compressed air creates a bubble which floats up through the water and then pressurizes the air volume in the top of the bottle.
• The bottle is released from the pump.
• The water is pushed out of the nozzle by compressed air.
• The bottle moves away from the water because it follows Newton's Third Law.

Reaction Mass
Water and gas are used in combination, with the gas providing a means to store potential energy, as it is easily compressed, and the water increasing the mass fraction and providing greater momentum when ejected from the rocket's nozzle. Sometimes additives are combined with the water to enhance performance in different ways.

Recovery system
A water rocket may use various kinds of recovery systems. Download a tutorial on Recovery Systems by clicking here.

Further Reference

• Water Rocket | Wikipedia This page gives an introduction to water rocketry, besides providing many useful links
  
• Water Rocket | YouTube Videos A number of interesting videos on Water Rocketry
  
• Google

Launcher

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