2A6X1 Vol. 2 Ure's (Mfe)

The section of a jet engine that introduces and burns fuel is the combustion section. This is where the fuel is mixed with air and ignited, creating a high-temperature and high-pressure gas that expands and provides the necessary thrust to propel the aircraft forward. The combustion section is crucial in converting the potential energy of the fuel into kinetic energy, which powers the engine and allows the aircraft to fly.

A barometer is used to measure barometric pressure. Barometric pressure refers to the pressure exerted by the atmosphere at a particular location. A barometer typically consists of a glass tube filled with mercury or aneroid cells that expand or contract based on atmospheric pressure. By measuring the changes in the height of the mercury column or the movement of the aneroid cells, the barometer can provide an accurate reading of the atmospheric pressure. This information is important for weather forecasting, as changes in barometric pressure often indicate upcoming weather patterns.

The turbine section of a jet engine keeps the compressor rotating. The turbine is connected to the compressor by a shaft, and as the hot gases from the combustion process pass through the turbine, they cause the turbine blades to rotate. This rotational energy is then transferred to the compressor, which keeps it spinning and allows it to continue compressing air for the combustion process. The turbine plays a crucial role in maintaining the continuous flow of air and fuel through the engine, making it an essential component for the engine's operation.

According to Bernoulli's principle, as the speed of a fluid (such as air) increases, its pressure decreases. In the case of an airfoil, the curved shape of the upper surface causes the air to travel faster, resulting in lower pressure above the airfoil. At the same time, the flat bottom surface of the airfoil causes the air to travel slower, resulting in higher pressure below the airfoil. This pressure difference creates an upward force, known as lift, which allows the airfoil to generate upward motion. Therefore, Bernoulli's principle best describes the combination of decreased pressure above an airfoil and increased pressure below the airfoil producing lift.

After a failed start, the fuel that accumulates is drained overboard by a drain system. This is done to prevent the fuel from causing any damage or malfunction in the fuel control system. By draining the fuel overboard, any potential hazards or risks are eliminated, ensuring the safety and proper functioning of the system.

Inertia is the correct answer because it refers to the tendency of an object to resist changes in its state of motion. An object at rest will remain at rest, and an object in motion will continue moving in a straight line at a constant speed unless acted upon by an external force. This property of inertia is a fundamental concept in physics and helps explain various phenomena in the physical world.

The turbine stator directs the gases onto the first-stage turbine wheel blades in a jet engine. The turbine stator is a stationary component that is located between the combustion chamber and the turbine wheel blades. Its primary function is to guide and direct the flow of gases onto the turbine blades, ensuring efficient energy transfer and power generation.

The turbine stator (nozzle diaphragm) is placed directly in front of each turbine wheel when two or more turbine wheels are used in a jet engine. The turbine stator is responsible for directing the flow of gases onto the turbine blades, ensuring efficient energy transfer and power generation. It helps to control the speed and pressure of the gases, optimizing the performance of the turbine wheels.

The stationary vanes positioned between rotor discs in a compressor are used to direct air and increase pressure. These vanes serve to guide the airflow and redirect it in a specific direction, ensuring that the air is efficiently compressed and the pressure is increased. By controlling the airflow, the vanes help optimize the compressor's performance and enhance its overall efficiency.

The radial drive shaft on an F108 engine connects the core engine to the accessory drive assembly. This means that it is responsible for transmitting power from the engine to various accessories, such as generators, pumps, and other components that require mechanical power. The accessory drive assembly is an essential part of the engine's overall functionality and ensures that all necessary accessories are properly powered and operational.

The turbine is the correct answer because it is one of the three major sections of all jet engines, along with the compressor and combustion sections. The turbine is responsible for extracting energy from the high-velocity gas flow produced by the combustion section and converting it into mechanical energy to drive the compressor and other engine components. It is located after the combustion section and before the exhaust section in the engine's flow path.

The excess airflow that is not burned in the combustion section is used to cool the burner surfaces. This is necessary because the combustion process generates high temperatures, and if the burner surfaces are not cooled, they can become damaged or even melt. By using the excess airflow for cooling, the burner surfaces can maintain a safe temperature and continue to function properly.

The most common type of fuel nozzle system is the pressure-atomizing system. This system uses high pressure to atomize the fuel into fine particles, allowing for efficient combustion. It is widely used in various applications, including gas turbines, industrial burners, and oil-fired boilers. The pressure-atomizing system ensures proper fuel distribution and combustion control, making it a popular choice in many industries.

The fuel control is responsible for metering fuel for combustion in an engine. It regulates the flow of fuel to ensure the correct fuel-to-air ratio for efficient combustion. This component plays a crucial role in controlling the engine's performance and optimizing fuel efficiency. The P&D valve, fuel pump, and fuel nozzles are also important components in the fuel system, but they do not specifically meter fuel for combustion like the fuel control does.

Before inspecting new jet engine bearings, it is necessary to remove the preservative coating. This is because the preservative coating is applied to protect the bearings during storage and transportation. However, it can interfere with the inspection process and potentially mask any defects or damage that may be present. Therefore, removing the preservative coating allows for a thorough and accurate inspection of the bearings to ensure their quality and functionality.

Arbor presses and bearing pullers are commonly used bearing removal tools. Arbor presses are used to apply pressure to remove bearings from a shaft or housing, while bearing pullers are used to grip and pull the bearing out. These tools are effective in safely and efficiently removing bearings without causing damage to the surrounding components. Drift pipes and hammers may be used in some cases, but they are not as commonly used as arbor presses and bearing pullers.

The total gear reduction ratio of the RGB is 13.54:1. This means that for every 13.54 revolutions of the input gear, the output gear will complete 1 revolution. This indicates a significant reduction in speed and an increase in torque, making it suitable for applications that require high torque output.

The correct answer is reaction-impulse. In jet engines, turbine and vane assemblies are used to convert the energy from the hot gases into mechanical energy to drive the compressor and other components. Impulse turbines work by the force of the gas jets impacting the turbine blades, while reaction turbines work by the pressure difference between the gas jets entering and leaving the turbine. However, there are also turbines that combine both impulse and reaction principles, known as reaction-impulse turbines. These turbines utilize both the impact force and the pressure difference to generate mechanical energy efficiently.

Heating the inner races of bearings before installation is necessary to expand the metal and make it easier to fit onto the shaft. A hot-oil bath is a recommended method because it provides a uniform and controlled heating process. The bearings are immersed in hot oil, which evenly distributes heat and ensures that the entire inner race reaches the desired temperature. This method is effective and minimizes the risk of overheating or damaging the bearings. Portable heaters, bearing furnaces, and hydraulic baths may not provide the same level of control and uniformity as a hot-oil bath.

The reduction geartrain is responsible for reducing the engine rotor speed to the rpm required for accessories. This component is designed to decrease the rotational speed and increase torque, allowing the engine to efficiently power various accessories such as alternators, power steering pumps, and air conditioning compressors. By using a series of gears with different sizes, the reduction geartrain is able to achieve the desired rpm for the accessories while maintaining the engine's optimal operating speed.

A divergent duct is designed to gradually increase in size, causing the gas to expand and slow down as it passes through. This expansion leads to a decrease in velocity and an increase in pressure.

The sea-level atmospheric pressure at "standard day" conditions is 14.7 psi. Atmospheric pressure is the force exerted by the weight of the air above a given point. At sea level, the average atmospheric pressure is about 14.7 pounds per square inch (psi). This value is considered the standard atmospheric pressure and is used as a reference point for measuring pressure at different altitudes.

After air is drawn into the guide vanes of a centrifugal compressor, it experiences two forces: rotational and centrifugal. The rotational force is caused by the spinning motion of the compressor impeller, which imparts a swirling motion to the air. The centrifugal force is a result of the air being pushed outward due to the high-speed rotation of the impeller. These two forces work together to compress the air and increase its pressure before it is discharged from the compressor.

The correct answer is "combustion chamber cross over tubes". The combustion chamber cross over tubes are responsible for directing the flow of hot gases from one combustion chamber to another. They play a crucial role in maintaining the proper flow and distribution of fuel and air mixture within the combustion section. Therefore, they need to be removed in a specific order to ensure that the combustion process is not disrupted and the engine operates efficiently.

The purpose of the exhaust duct is to straighten the exhaust gas-flow. This means that the duct is designed in a way that allows the exhaust gas to flow in a straight and smooth manner, reducing turbulence and improving the efficiency of the exhaust system. By straightening the gas-flow, the exhaust duct helps to minimize resistance and pressure drop, allowing for better performance and optimal functioning of the exhaust system.

The major sections of a turboprop engine include the power unit, torquemeter assembly, and RGB assembly. The power unit is responsible for generating the power needed to drive the propeller. The torquemeter assembly measures the torque produced by the engine. The RGB assembly, which stands for Reduction Gearbox, is an important component that reduces the high-speed output of the turbine to a suitable speed for driving the propeller. It is responsible for transmitting power from the engine to the propeller efficiently. The compressor assembly and combustion assembly are also important sections of a turboprop engine, but they are not mentioned in the question.

The overall reduction ratio of the RGB's main reduction gear train on the T56 turboprop engine is 13.54 to 1.

The correct answer is "is a forged single unit." This means that the impeller of the centrifugal compressor is made as a single piece through the process of forging. This constructional feature ensures that the impeller is strong and durable, as it eliminates any weak points or joints that could potentially fail under high-speed rotation. By being a single unit, the impeller can efficiently convert the kinetic energy of the rotating blades into pressure energy, resulting in an effective compression process.

Swirl-type fuel nozzles are designed to provide a high flame speed. The swirling motion of the fuel and air mixture enhances the mixing and combustion process, resulting in a faster and more efficient flame propagation. This high flame speed is beneficial in applications where quick and complete combustion is desired, such as in gas turbines or industrial burners.

The purpose of an augmentor (afterburner) in a jet engine is to increase the basic engine thrust. By injecting additional fuel into the exhaust stream and igniting it, the afterburner generates extra thrust, significantly enhancing the engine's power output. This allows the aircraft to achieve higher speeds and perform maneuvers that require greater thrust, such as takeoff, supersonic flight, or combat situations. The augmentor is a crucial component in maximizing the performance capabilities of a jet engine.

When handling jet engine bearings, it is necessary to change cotton gloves frequently because they get soaked with sweat. Sweat can make the gloves wet and damp, reducing their effectiveness in providing a good grip and protection. Additionally, wet gloves can also lead to discomfort and potential skin irritation. Therefore, changing the gloves frequently ensures that they remain dry and maintain their functionality during the handling process.

The LPT shaft assembly connects the fan shaft with the LPT rotor. The LPT rotor, also known as the Low-Pressure Turbine rotor, is responsible for extracting energy from the hot gases exiting the combustion chamber and converting it into rotational energy to drive the fan and compressor stages. Therefore, it makes sense that the LPT shaft assembly would connect the fan shaft with the LPT rotor to transfer this rotational energy efficiently.

Kerosene has a heat content of 18,500 BTU's per pound. This means that when one pound of kerosene is burned, it releases 18,500 BTU's of heat energy.

The divergent design of a diffuser increases air pressure. A diffuser is a device that gradually expands the flow area of a fluid, in this case, air. As the air flows through the divergent section of the diffuser, the cross-sectional area increases, causing the air to slow down. According to Bernoulli's principle, when the velocity of a fluid decreases, its pressure increases. Therefore, the divergent design of a diffuser increases air pressure.

Vane-type fuel pumps used in jet engines are similar to sliding-vane air compressors. Both types of pumps use a set of vanes that slide in and out of slots in a rotor to create a seal and move fluid or air. This design allows for efficient and reliable pumping, as the vanes create a positive displacement action. The sliding-vane air compressor is a suitable comparison as it operates on the same principle, using vanes to compress air instead of pumping fuel. The other options, piston pump air compressors, roots air compressors, and turbo-superchargers, do not share the same design or operation as vane-type fuel pumps.

The stationary (stator) vane blades on the T56 compressor are used to increase pressure. These blades are strategically placed in the compressor to redirect the airflow and create a higher pressure zone. As the air passes through the stator vane blades, its velocity decreases and its pressure increases. This is crucial for efficient compression and improved performance of the compressor. By increasing the pressure, the stator vane blades contribute to the overall effectiveness and functionality of the T56 compressor.

Primary airflow in the F108 engine is through the booster, core engine, and low-pressure turbine components. The accessory gearbox, on the other hand, is not a component through which primary airflow occurs. Therefore, it is the correct answer.

A turboprop engine uses the method of accelerating a large mass of air by a small amount to produce thrust. This is achieved by using a gas turbine engine to drive a propeller, which in turn accelerates a large quantity of air behind it. By accelerating a large mass of air by a small amount, the engine is able to generate the necessary thrust to propel the aircraft forward efficiently.

Directing air around the plug helps prevent igniter plug fouling. By directing air around the plug, any deposits or contaminants that may accumulate on the plug are blown away, reducing the chances of fouling. This ensures that the plug remains clean and functional, allowing for efficient ignition of the engine. Gold plating on the plug, split electrode on the plug, and ceramic coating on the plug may have other benefits in engine design, but they do not specifically address the prevention of igniter plug fouling.

Nicks are a type of defect that appear on bearings as a result of bearing parts striking together. When the bearing parts collide or experience impact, small chips or dents can be formed on the surface, which are known as nicks. These nicks can lead to increased friction, reduced performance, and potential failure of the bearing over time.

Grooves appear on bearings as a result of small particles of foreign material becoming lodged between the rollers. These particles can cause wear and tear on the surface of the bearing, creating grooves or indentations. This can lead to reduced performance and increased friction in the bearing, potentially causing it to fail prematurely.

Excessive bearing wear can usually be detected by the roughness of metal. When a bearing wears excessively, the smooth surface of the metal becomes rough due to friction and wear. This roughness can be felt or observed by touching or visually inspecting the bearing. It indicates that the bearing is no longer functioning properly and may need to be replaced or repaired.

The T700 engine AGB routes oil and fuel through internal passages. This means that the oil and fuel flow through channels or pathways that are located within the engine itself. These internal passages ensure that the oil and fuel are properly distributed and delivered to the necessary components of the engine, allowing it to function efficiently.

The secondary airflow on the F108 engine produces 80% of the total engine thrust. This means that a significant portion of the engine's power is generated by the secondary airflow, indicating its importance in the overall functioning of the engine.

The pinion input gear rotates at the same speed as the power unit rotors in the T56 engine.

The "fir tree" method of attaching turbine blades to the turbine rotor disc is preferred because there is a significant temperature differential between the turbine rotor disc and the blades. This method allows for better thermal expansion and contraction of the blades, reducing the risk of damage or failure due to the temperature difference. By securely attaching the blades using the "fir tree" method, it ensures that they can withstand the stress caused by the temperature differential without any horizontal or axial movement, thus maintaining the efficiency and reliability of the turbine.

The correct answer is 14 stage axial-flow. This means that the compressor rotor assembly on the AE2100D3 engine consists of 14 stages of axial-flow compression. Axial-flow compressors use a series of rotating and stationary blades to compress the air in a parallel flow direction, resulting in efficient compression. The number of stages refers to the number of sets of rotating and stationary blades, with each stage contributing to the overall compression of the air. In this case, the compressor rotor assembly has 14 stages of axial-flow compression.

The given statement describes Newton's second law of motion. According to this law, an unbalanced force acting on an object will cause the object to accelerate in the direction of the force. The acceleration is directly proportional to the force applied and inversely proportional to the mass of the object. This law is commonly expressed as F = ma, where F is the force, m is the mass, and a is the acceleration.

Brake horsepower is the type of horsepower that is delivered to the propeller for useful work. Brake horsepower refers to the actual power output of an engine or motor, measured at the output shaft. It represents the power available to do useful work, such as turning the propeller in this case, after accounting for any losses due to friction or other inefficiencies.

The turbine nozzle vane assembly is placed in front of the rotating blades in an engine turbine section. This assembly consists of multiple nozzle vanes that direct the flow of hot gases onto the turbine blades, allowing for efficient energy transfer and power generation. The nozzle vanes help to control the flow of gases and ensure that they are directed onto the blades at the correct angle and velocity, maximizing the turbine's performance.