Sunday, July 26, 2009

5. BASIC REQUIREMENTS FOR A HYPERPLANE(Seminar Hyperplane)

The hyperplanes have lot of differences in its design and working, therefore some basic requirements have to be met .They are,

JET ENGINES
Jet engines are required if horizontal take off is needed ( take off like other planes). Normal jet engines can be used for this purpose which will power the air craft to the height required for the working of ramjet engines and rocket engines. The main need for this arises since a scramjet engine cannot be started from zero velocity.

BOOSTER ROCKET ENGINE
rocket-based combined-cycle engines, which could be used in a space vehicle, rely on a rocket that is integrated within the scramjet combustor to provide thrust from takeoff through subsonic, low-supersonic and then ramjet speeds. Ramjet operation is then followed by scramjet propulsion to at least Mach 10 or 12, after which the rocket is utilized again to supplement the scramjet thrust. Above Mach 18, the rocket by itself propels the vehicle into orbit and enables it to maneuver in space. NASA is currently testing several variations of such a system. Hyper-X uses only the first stage of Orbital's Pegasus rocket . For a typical space launch, the Pegasus features three stages. The Pegasus stage has some alterations just for X-43 launches, but it is basically the same booster used to deliver small satellite payloads into Earth orbit.

SCRAMJET AIR BREATHING ENGINE
A scramjet (supersonic combustion ramjet) is a variation of a ramjet with the distinction being that some or all of the combustion process takes place supersonically. At higher speeds, it is necessary to combust supersonically to maximize the efficiency of the combustion process. Projections for the top speed of a scramjet engine (without additional oxidiser input) vary between Mach 12 and Mach 24 (orbital velocity). A scramjet is a type of jet engine designed to operate at the high speeds typically associated with rockets. Its main difference from a rocket is that it collects air from the atmosphere to burn its fuel, rather than carrying an oxidizing substance on board. More conventional jets (turbojets, turbofans and ramjets) share this characteristic but are unsuitable for the high speeds at which scramjets can operate.

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