Introduction
In this lab report, the item that is selected to analyze, is a turbine blade, specifically in the aviation purposes such as a jet engine/gas turbine. This part was picked because it is a crucial part in the field of aviation, and there are many different aspects and techniques that go into producing them. Turbine blades have to deal with extreme conditions such as high temperature and high pressure gas, high vibration, and high stress, which is why they are usually the limiting factor in a jet engine.
Background
The turbine is a part of a jet or gas engine. A jet engine consists of 4 main parts: the air intake, the compression, the combustion, and the exhaust. The intake is responsible for collection as much air as possible into the engine. Throughout the compression phase, air is compressed causing to to move at higher velocity. It is then mixed with fuel in the combustion chamber to create even more pressure. The turbine then propels this extremely hot and high pressured air out through the exhaust. The exhaust is in a funnel shape which increases the gas velocity even more [1]. The turbine is definitely the component of a jet engine that undergoes the toughest conditions which is why it is so crucial. Material Scientists are inventing new materials and techniques to create better properties to improve the quality of the turbine blade.
History
Since the invention of jet engines, there has always been a steady increase in their power and efficiency. As a comparison, the air temperature inside the turbine has risen from about 600 degrees Celsius to over 1500 degrees Celsius. This change has caused a 60% increase in power and a 20% decrease in fuel usage. These drastic changes have also caused a change in the materia...
... middle of paper ...
... Ceramics and Their Applications. Weinheim: Wiley-VCH, 2008. Web. 1 Dec. 2013. .
[11]
Ceramic Matrix Composite. Digital image. N.p., n.d. Web.
[12]
"Materials Engineering." Fabrication of Ceramic Matrix Composites by Chemical Vapor Infiltration (CVI) [SubsTech]. N.p., n.d. Web. 03 Dec. 2013.
[13]
"Ceramic Matrix Composite Disc Brakes." - Appropedia: The Sustainability Wiki. N.p., n.d. Web. 09 Dec. 2013.
[14]
Wikipedia contributors. "Ceramic matrix composite." Wikipedia, The Free Encyclopedia. Wikipedia, The Free Encyclopedia, 14 Nov. 2013. Web. 10 Dec. 2013.
Side note: We are aware it’s wikipedia, but it cites 30 reliable sources which are all academic journals. Most of the sites required payment so we were unable to cite those sources which is why we had to resort citing wikipedia for the general information.
Encyclopedia Britannica Online. Encyclopedia Britannica, n.d., pp. 113-117. Web. The Web.
Some ceramics are used in orthopaedic applications such as bone repair, bone augmentation and joint replacement but their use in this field is not as extensive or widespread as metals and polymers because ceramics have poor fracture toughness. This severely limits the use of ceramics in load bearing applications (Davis, 2003).
A wind turbine is a device that converts kinetic energy from the wind into electrical power. Small wind turbines we discussed for domestic use have fewer requirements to properties, but more considerations of cost compared to large wind turbine.
The aim is to achieve a very dense matrix using extremely low water/binder (w/b) ratio (0.13-0.24) and by optimizing the granular packing of the dry fine powders. The resulting compactness gives RPC ultra-high strength and durability6. Table 1 shows the various components of RPC and their selection parameters.
The jet engine is a great mechanical piece of engineering. It has been used in almost all aircraft since its invention. This one improvement in aircraft allowed aircraft to fly higher, faster, and more efficient. The turbocharged engine invented by GE was the main building block for other engines. Since its invention, the jet engine has been the workhorse for all jet powered aircraft.
Turbofan engine gives rise to greater complexity due to additional ducting e.g. addition of multiple shafts, heavy blades.
Now when it comes to windshield wipers, they are mostly built of flexible metal along with some sort of rubber lining on top of it to prevent it from being damaged early. Now, these windshield wipers use different types of blades that are used to clean the windshield.
In everyday life, there are things that one needs to survive. And sustainability problems arise every day. One such problem is energy loss. The world is using up a lot of energy and new ideas need to be formed to help the rest of the world and the future of the generations that are to follow, to survive. With that the problem is that people use up energy and they do not use it efficiently. Therefore scientists are needed to find ways to deal with the sustainability problem that is arising. That is where wind turbines are used to generate this energy but the actual wind-turbines are very large, loud and they kill birds, thus new designs need to be found in order to help energy usage and to bring the size and structure of the wind turbines to a smaller scale to prevent injuries to nature and the species around it.
A steam turbine's two main parts are the cylinder and the rotor. As the steam passes through the fixed blades or nozzles it expands and its velocity increases. The high-velocity jet of steam strikes the first set of moving blades. The kinetic energy of the steam changes into mechanical energy, causing the shaft to rotate. The steam then enters the next set of fixed blades and strikes the next row of moving blades. As the steam flows through the turbine, its pressure and temperature decreases, while its volume increases. The decrease in pressure and temperature occurs as the steam transmits energy to the shaft and performs work. After passing through the last turbine stage, the steam exhausts into the condenser or process steam system. The kinetic energy of the steam changes into mechanical erringly through the impact (impulse) or reaction of the steam against the blades.
A wind turbine is a device that converts kinetic energy from the wind into mechanical energy. If the mechanical energy is used to produce electricity, the device may be called a wind generator, wind charger or wind turbine. If the mechanical energy is used to drive machinery, such as for grinding grain or pumping water, the device is called a windmill or wind pump (Niki 2007). Today modern wind turbines typically have three blades. The blades are usually colored light gray to blend in with the clouds and range in length from 20 to 40 meters or more. The tubular steel towers range from 60 to 90 meters tall. The blades rotate at 10-22 revolutions per minute. At 22 rotations per minute the tip speed exceeds 91 meters per second (Rosenbloom, 2006). The modern horizontal-axis, three-bladed wind turbine can be divided into three main components. First, the rotor component, which includes the blades for converting wind energy to low speed rotational energy. Second is the generator component, which includes the electric generator, the control electronics, and most likely a gearbox component for converting the low speed incoming rotation to high speed rotation suitable for generating electricity. The control system engages protective features to avoid damage at high wind speeds. Finally, the structural support component includes the tower and rotor yaw mechanism that turns the turbine towards the wind. (Office of Energy Efficiency and Renewable Energy, 2006)
The wind passes over the blades creating lift (like an aircraft wing) which causes the rotor to turn. The blades turn a low-speed shaft inside the nacelle: gears connect the low speed shaft of the rotor with a high speed shaft that drives a generator. Here, the slow rotation speed of the blades is increased to the high speed of generator revolution. Some wind turbines do not contain a gearbox and instead use a direct drive mechanism to produce power from the generator.
The systems of the modern wind turbine consist of three components, a tower, a rotor, and a nacelle. The tower is where the wind turbine is mounted. The rotor is the component turned by the wind itself. The nacelle is the place that houses all of the equipment including, the generator, which converts the mechanical energy in the active rotor into electricity. All of these parts must be kept in top shape and be made of extremely strong materials.
Composites are similar to essays; they are both an arrangement of parts coming together. Composites, however, have two essential phases: matrix and dispersed phase. The matrix’s responsibility is to be covering the materials being used to form a new type of supply. Composites are also known as two or more type of materials being combine to create a new material that could be used in different real world applications. Commonly, composites are formed because it could be reusable, cheaper and sometimes a stronger material. Three of the most common use materials to form composites are metals, polymers and ceramics [1]. The combination of these materials provides suppliers more opportunities to create composites that will be used often in the market. But to construct composites, suppliers must understand how composites work. They are divided into three different composites: particle-reinforced composites, fiber-reinforced composites, and structural composites [1].
The Wind Turbine is a device that converts the kinetic energy of the wind into kinetic energy of turbines. The turbines turn to generate electricity but they work only when there is wind. The efficiency is 30-40%. The environmental impacts are needs many large turbines to generate electricity which can be noisy and unsightly. Turbines may endanger birds and bats.