Short answer The geometry of the disc and the material of the disc both affect the stiffness of the disc. If you are looking for a trade-off between stiffness and weight then you can employ tricks like ribs or hollow pockets inside the disc. If I had to suggest a material and money was no problem, I would say graphene or some other nano-engineered material where you could design the stiffness properties at the molecular level.
In 10, the Wright Brothers flew, The Flyer, with a 1 horse power gas powered engine. But it was Frank Whittle, a British pilot, who designed the first turbo jet engine in The first Whittle engine successfully flew in April, This engine featured a multistage compressor, and a combustion chamber, a single stage turbine and a nozzle.
The first jet aeroplane to successfully use this type of engine was the German Heinkel He invented by Hans Von Ohain. It was the worlds first turbojet powered flight. Since this date, the engineers start to developed this kind of engine because they can offer more power to make the plane fly faster and Higher.
Improvements in the performance of gas turbine have been intimately linked to the development of materials technologies for high-temperature components. Engine performance and durability have been limited by the availability of suitable materials for the very high temperatures and high stresses endured by many of the components.
Furthermore, the environment is very harsh chemically and mechanical, with very large forces generated by the high rotational speeds and even the possibility of birds being sucked into the engine!
The maximum service temperature chart on the bottom is a useful way of identifying new possibilities for materials development.
But the figure below shows that the remarkable improvements in aero-engine performance have come about because the materials designer has been able to provide the engineer with materials can be used at hotter temperatures.
Higher engine temperatures are needed so that the engines can run more efficiently, while weight reductions require stiffer, stronger, and lighter materials. What will the future reserved to the engineers? At the present time titanium and nickel alloys are used for the low and high temperature parts, but some other solution have already been developed for allow highest temperature in aero-engine, and the future research are concerned with ceramics which appear to have the best high temperature properties.
It show also how we can use a combination of ceramics coatings and metal alloy to increase the operating temperature until the next development of ceramics.
Turbine composition and temperature The basic mechanical arrangement of a gas turbine is relatively simple. It consists of only four parts 1. The compressor which is used to increase the pressure and temperature of the inlet air.
One or a number of combustion chambers in which fuel is injected into the high-pressure air as a fine spray, and burned, thereby heating the air.
The pressure remains nearly constant during combustion, but as the temperature rises, each kilogram of hot air needs to occupy a larger volume than it did when cold and therefore expands through the turbine.
The turbine which converts some of this temperature rise to rotational energy. This energy is used to drive the compressor.
The exhaust nozzle which accelerates the air using the remainder of the energy added in the combustor, producing a high velocity jet exhaust.
The amount of fuel added to the air will depend upon the temperature rise required. Because by cooling the material during its operation, they can increase the operating temperature of the turbine.
Materials scientists have worked hard to increase the operating temperature of todays alloys, and for reaching this aims they have made the following modification and use the following tricks - turbine blades are grown as single crystals, because these are more resistant to creep gradual changes in dimensions under stress and temperature ; - current nickel superalloys contain expensive alloying elements such as Hafnium and Rhenium in order to increase their high temperature performance; - turbine blades have little networks of holes to air-cool the blade surface.
Metals alloys In Aero Engines the development of highly engineered super alloys has become necessary. Developments in advanced materials have contributed to the spectacular progress in thrust-to-weight ratio of the aero engine. And also this has enabled significant improvements in performance and reliability.
This has been achieved mainly through the substitution of titanium and nickel alloys for steel. Aluminium has virtually disappeared from the aero engine, and the future projection illustrates the potential for composites of various types.
The airframe is still mainly aluminium due to the lower requirements. Aeropropulsion turbines will eventually use more of the light advanced high-temperature materials such as intermetallics, carbon matrix composites, and metal matrix composites.
However, enhancements in coatings and cooling have extended the performance and value of nickel-based superalloys, so they are not yet out of the running. In aero-engines, the blade of the high pressure turbine was for a long time the highest of the high technology in the aero gas turbine, and despite the complexity of the modern fan blade, the challenge it provides does not reduce.
The ability to run at increasingly high gas temperatures has resulted from a combination of material improvements and the development of more sophisticated arrangements for internal and external cooling 1-Modern Alloys A modern turbine blade alloy is complex in that it contains up to ten significant alloying elements, but its microstructure is very simple.
Magnesium alloy developments have traditionally been driven by aerospace industry requirements for lightweight materials to operate under increasingly demanding conditions such as high temperature ranges. Magnesium alloys have always been attractive to designers due to their low density, only two thirds that of aluminium.
This has been a major factor in the widespread use of magnesium alloy castings and wrought products. A further requirement in recent years has been for superior corrosion performance and dramatic improvements have been demonstrated for new magnesium alloys.
Improvements in mechanical properties and corrosion resistance have led to greater interest in magnesium alloys for aerospace and speciality applications.
The high strength and low density of titanium and its alloys have from the first ensured a positive role for the metal in aero-engine applications. It is difficult to imagine how current levels of performance, engine power to weight ratios, strength, aircraft speed and range and other critical factors could be achieved without titanium.
This would allow most compressors to be designed completely in titanium.Jun 08, · Titanium alloys capable of operating at temperatures from sub zero to ¢XC are used in engines for discs, blades, shafts and casings from the front fan to the last stage of the high pressure compressor, and at the rear end of the engine for lightly loaded fabrications such as .
Automobile: Automobile, a usually four-wheeled vehicle designed primarily for passenger transportation and commonly propelled by an internal-combustion engine using a volatile fuel. The modern automobile is a complex technical system employing subsystems .
The blade clearance depends on the radial growth of the compressor discs, which in turn depends Read more. Increasing pressures in gas-turbine compressors, particularly in aeroengines where the pressure ratios can be above , require smaller compressor blades and .
size of LP TURBINE BLADES is generally greater than that of HP TURBINE BLADES. At the first T1, T2, T3 & T4 kinds of blades were used, these were 2nd generation blades.
Stiffening of Tesla turbine rotors. The geometry of the disc and the material of the disc both affect the stiffness of the disc. Smaller radius = stiffer. Thicker disc = stiffer. Why do thicker turbine blades delay flow separation?
1. Does the turbine outlet affect the power generated by the turbine? 1.