The thrust and fuel consumption elements, and their variation with altitude, are of vital importance in the climb and cruise phases of operation of the aircraft.The behaviour of a jet engine and its effect both on the aircraft and the environment is categorised into different engineering areas or disciplines.
The thrust and fuel consumption elements, and their variation with altitude, are of vital importance in the climb and cruise phases of operation of the aircraft.The behaviour of a jet engine and its effect both on the aircraft and the environment is categorised into different engineering areas or disciplines.It tends to increase as energy is converted between different forms, i.e. The TS diagram shown on the RHS is for a single spool turbojet, where a single drive shaft connects the turbine unit with the compressor unit.Tags: Newview Essay Services Online SoftwareEssay Paragraph LayoutDescription Of English Essays Letter WritingPay People To Write EssaysEssay Human Philosophy ScienceBiology Coursework PlanningAdmirable EssayThe Jungle Essay
The fundamental performance task for a single shaft turbojet is to match the operation of the compressor, turbine and propelling nozzle.
For example, the way the compressor operates is determined by the flow resistances behind it, which occur in the combustor, turbine, tailpipe and propelling nozzle.
The thrust available is restricted by the turbine temperature limit at high ambient temperatures as explained in the "Rated performance" sections. entropy (TS) diagrams (see example RHS) are usually used to illustrate the cycle of gas turbine engines.
Entropy represents the degree of disorder of the molecules in the fluid.
The shallower the positive slope on the TS diagram, the less efficient the compression process.
The temperature rise in the compressor dictates that there will be an associated temperature drop across the turbine.Below are the equations for a single spool turbojet.A simplifying assumption sometimes made is for the addition of fuel flow to be exactly offset by an overboard compressor bleed, so mass flow remains constant throughout the cycle.The effects of over-fuelling and under-fuelling which occur with changes in thrust demand are covered in "Transient model".There is an explanation of the Husk plot which is a concise way of summarising the performance of the engine.However, the specific fuel consumption (fuel flow/net thrust) is unaffected, assuming scale effects are neglected.Similar design point calculations can be done for other types of jet engine e.g. The method of calculation shown above is fairly crude, but is useful for gaining a basic understanding of aeroengine performance.Most engine manufacturers use a more exact method, known as True Specific Heat.High pressures and temperatures at elevated levels of supersonic speeds would invoke the use of even more exotic calculations: i.e. The first term is the momentum thrust which contributes most of the nozzle gross thrust.In fixed-wing aircraft driven by one or more jet engines, certain aspects of performance such as thrust relate directly to the safe operation of the aircraft whereas other aspects of the engine operation such as noise and engine emissions affect the environment.The thrust, noise and emission elements of the operation of a jet engine are of vital importance in the takeoff phase of operation of the aircraft.