Passive recovery systems help slow the descent without changing the profile of the rocket.īacksliders are the rockets that are modified so that at apogee, instead of flipping over and heading for the ground, they float back in a higher drag configuration than a nose-dive. You will want to be very careful when designing your wings as to prevent violation of the definition of a parachute or the change of shape rule. A great guide to backslider construction can be found in the links below. Backsliders are the rockets that are modified so that at apogee, in stead of flipping over and heading for the ground, they float back in a higher drag configuration than a nose-dive. A few of the systems you should experiment with are backsliders and gliders. The rules state that "Rockets must not change shape or deploy and type of recovery system." This bans parachutes and any other non-rigid recovery devices. Labels can be removed, but need to be presented to the judges to prove the size and other information about the bottle. it must not be spray painted or covered in opaque duct tape. The inside of the vessel must be able to be inspected, i.e. The rocket's pressure vessel in Bottle Rocket is an unmodified standard 1 liter plastic carbonated beverage bottle of any shape or color. The fins: used to add stability to the rocket, usually 3 or 4 of them Pressure Vessel Usually the top of a plastic egg works great. The nose cone: cone shape on top of bottle that is beneficial and necessary to achieve winning times. The bottle: a standard 1L carbonated bottle of any shape or color that is not modified in any way B. The following are the components of most bottle rocket designs:Ī. It can also be a good idea to bring a container or other form of covering for a rocket in the case of rain at a competition. While these factors cannot be completely mitigated or predicted, bottle rockets can be made to function in as many environments as possible through practice and testing. However, you should also remember that chance favors the prepared mind. Before reading any further, you must understand that chance does play a role in the event, as prevailing winds, humidity, temperature, and other weather conditions can all affect rocket performance. More information on backsliding may be found in the Recovery System section below.īottle Rocket has built up a bit of a reputation as an event that is affected significantly by chance. This is a form of passive recovery system that slows the fall of the rocket, thus increasing its total flight time and decreasing the velocity at which it strikes the ground, making the egg less likely to break. Under the current rules, backsliding is used as the primary recovery system for the rocket. Fins may also be added to the rocket, but their shape and size does not appear to have a large influence on height. One suggestion is adding a penny at a time until the rocket's height at apogee starts to lower, which should make it easier to find the rocket's optimal balance. Achieving stability often means adding weight to the end of the nose cone.Īgain, a good way of finding stability is by launching the rocket with different amounts of weight put in different places. The center of pressure is the point where the rocket would be balanced vertically if held in a strong wind. The center of gravity may be found by balancing the rocket on a finger the center of gravity of the bottle rocket will be directly above this point. Maximum stability occurs when the center of gravity is ahead of the center of pressure. This is not always true, as stability is required to achieve maximum height. The most common misconception is that the lighter a rocket is, the higher it will go. This will achieve some success, but a combination of both is required to have maximum success. One strategy is to go all out on one of these by either having a rocket that goes almost out of sight but has a weak backslide or having a rocket with great backslide that doesn't go that high. These in combination will get a high time of flight. There are two basic factors that work towards time: height and cone (backsliding). This page provides some of what has been learned over the past few years, but there is no substitute to experimenting with one's own designs! Major Factors It also helps to watch other team's rockets at competitions and see how they perform. To build a competitive rocket, experiment! The more rockets launched, the better idea one will get of what works and what doesn't. Before even thinking about time, make sure eggs do not break! Rockets with broken eggs are placed in lower tiers than ones with 2 surviving eggs. An egg survived if it leaves no wet spot on a paper towel. The objective of this event is to get your rocket to stay up as long as possible, while also avoiding breaking the egg.
0 Comments
Leave a Reply. |