2A651 Edition 2 Vol.2 Ure

The recommended method of expanding a bearing race before installation is to use a hot-oil bath. This method involves heating the bearing race in a bath of hot oil, which causes the metal to expand. This allows for easier installation of the bearing race onto the shaft or housing. The hot oil provides a uniform and controlled heat source, ensuring that the bearing race expands evenly and avoids any damage or distortion.

Carbon monoxide gas is poisonous and odorless, and it has no color. This means that it cannot be detected by our senses, making it extremely dangerous. The lack of color allows it to go unnoticed, increasing the risk of inhalation and poisoning. It is important to have proper detection systems in place to ensure the safety of individuals in environments where carbon monoxide may be present.

The ability to do work is often defined as energy. Energy is the capacity or ability to perform work, whether it is in the form of mechanical, thermal, electrical, or any other type of energy. In this context, inertia, friction, and velocity are not definitions of the ability to do work, making energy the correct answer.

Fuel for an engine represents potential energy. Potential energy is stored energy that can be converted into other forms, such as kinetic energy, to perform work. In the case of an engine, fuel is burned to release energy, which is then used to power the engine and produce thrust or horsepower. Therefore, the fuel in an engine represents the potential energy that can be harnessed to perform work and power the engine.

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. Removing the coating allows for a thorough inspection of the bearings to ensure they are in proper working condition and free from any defects or damage.

The correct answer is kerosene and gasoline. Jet fuel is typically composed of a mixture of kerosene and gasoline. Kerosene provides the necessary energy and stability for the engine, while gasoline helps to improve the fuel's performance and cold weather capabilities. This combination of fuels ensures that the jet engine operates efficiently and reliably.

The stationary vanes positioned between rotor discs in a compressor are used to direct air and increase pressure. These vanes serve as a guide for the air as it flows through the compressor, ensuring that it is directed in the desired direction and increasing its pressure in the process. This is an important function in the compressor's operation, as it allows for the efficient compression of air or gas.

Arbor presses and bearing pullers are the most commonly used tools for removing bearings. Arbor presses are used to apply pressure and force to remove the bearing from its housing, while bearing pullers are designed specifically to grip and pull out the bearing. These tools are effective and widely used in various industries for bearing removal purposes.

Penetration is not a method of heat transfer. The other three options, radiation, convection, and conduction, are all recognized methods of heat transfer. Radiation refers to the transfer of heat through electromagnetic waves, convection involves the transfer of heat through the movement of fluids or gases, and conduction is the transfer of heat through direct contact between two objects. Penetration, on the other hand, does not describe a recognized method of heat transfer.

The highest point of temperature in an engine is reached in the combustion section. This is where the fuel and air mixture is ignited, resulting in the combustion process that generates the power needed to drive the engine. The combustion section is designed to withstand high temperatures and pressures, making it the location where the highest temperature is reached.

The leading edge vanes on an F100-PW-220 engine are hollow so that anti-icing air can flow through them. This is important because during flight, ice can accumulate on the leading edge of the engine, which can disrupt the airflow and affect the engine's performance. By allowing anti-icing air to flow through the hollow vanes, the ice can be prevented or removed, ensuring the engine operates efficiently and safely.

The purpose of the exhaust duct is to straighten exhaust gas-flow. This is important because exhaust gases often exit the engine in a turbulent and chaotic manner. By straightening the flow, the exhaust duct helps to improve the efficiency of the system and reduce turbulence, allowing for a smoother and more controlled release of exhaust gases.

Swirl-type fuel nozzles are typically used to provide a high flame speed. The swirling motion created by these nozzles helps to enhance the mixing of fuel and air, resulting in a more efficient and faster combustion process. This increased flame speed can be beneficial in applications where a rapid and intense combustion is desired, such as in certain types of burners or engines.

A turboprop engine uses the method of accelerating a large mass of air through a small velocity change to produce thrust. This means that the engine takes in a large amount of air, compresses it, and then accelerates it through the propeller at a relatively low velocity. This creates a high amount of thrust, allowing the aircraft to move forward efficiently.

Before installing separable bearings, it is important to ensure that the bearings are a matched set. This means that the bearings are specifically designed to work together and have the same specifications. Using mismatched bearings can result in improper functioning and potential damage to the equipment. Therefore, it is crucial to check that the bearings are a matched set before installation.

Vane-type fuel pumps used in jet engines are similar to sliding-vane air compressors. Both of these devices use a set of vanes or blades that slide in and out of slots in a rotor to create a pumping action. This design allows for efficient and reliable fuel or air flow, making it suitable for high-performance applications like jet engines. The other options, piston pump air compressors, roots air compressors, and turbo-superchargers, do not have the same sliding-vane mechanism and therefore are not as similar to vane-type fuel pumps.

After a failed start, the fuel that accumulates is drained overboard by a drain system. This is done to remove the excess fuel and prevent any potential hazards or damage. Draining the fuel overboard ensures that it does not remain in the system and allows for a fresh start in the next attempt.

The most common type of fuel nozzle system is pressure-atomizing. This system uses pressure to atomize the fuel into small particles, allowing for efficient combustion. This type of system is widely used in various applications, including automotive engines and industrial burners. It is preferred due to its ability to provide a fine spray of fuel, which promotes better fuel-air mixing and combustion efficiency.

To cause an accessory in a jet engine to operate at its most optimum speed, design engineers must change the gear ratio. This means altering the ratio between the input and output gears in the system, which will result in a change in the speed of the accessory. By adjusting the gear ratio, the engineers can ensure that the accessory operates at the most efficient speed for optimal performance. This is important for maintaining the overall efficiency and functionality of the jet engine.

The percentage of combustion efficiency of a gas turbine refers to the amount of fuel that is effectively converted into useful energy. A higher percentage indicates a more efficient combustion process. The given correct answer states that the combustion efficiency of a gas turbine is usually between 95 and 100 percent. This means that the majority of the fuel is being effectively converted into energy, resulting in a highly efficient combustion process.

The most probable cause of a flameout of a jet engine flying at 40,000 feet with a constant engine rpm of 50 percent is that the rpm is too low. When the engine rpm is too low, it can lead to insufficient fuel combustion and result in a flameout, causing the engine to shut down.

The parts on a can-annular combustion section must be removed in a specific order because the combustion chamber crossover tubes are interconnected with other components and removing them first allows for easier access to the remaining parts.

After the engine is shut down, any fuel that has accumulated in the T56 engine combustion section is released or expelled through drain valves, which allow the fuel to be vented overboard. This is done to prevent the fuel from causing any damage or potential hazards during the next start attempt.

The section of a jet engine that introduces and burns fuel is called the combustion section. In this section, fuel is mixed with compressed air and ignited, creating a high-temperature and high-pressure gas. This gas then expands and passes through the turbine, where it drives the compressor and provides thrust to the engine. The combustion section is a crucial part of the jet engine as it converts the chemical energy in the fuel into mechanical energy, which powers the aircraft.

The energy that is absorbed by the turbine wheel is returned to the compressor. This means that the energy is recycled and used again in the system, rather than being wasted. This is an efficient way to utilize the energy and maximize its usage within the turbine system.

The turbine stator directs the gases onto the first-stage turbine wheel blades in a jet engine. The stator is a stationary component that is located between the combustion chamber and the turbine wheel. Its purpose is to guide and direct the flow of gases, ensuring that they pass through the turbine blades at the correct angle and velocity to maximize efficiency and power output.

The correct answer is interlocking stainless-steel bands. This means that the inner and outer surfaces of the annular-type combustion chamber are made up of stainless-steel bands that interlock with each other. This design allows for a secure and efficient combustion process within the chamber.

The correct answer is "Brake." Brake horsepower refers to the amount of power that is delivered to the propeller for useful work. It represents the actual power output of the engine and takes into account any losses due to friction or other factors.

When bearing parts strike together, it can cause small chips or nicks on the surface of the bearing. These nicks can be caused by various factors such as misalignment, excessive load, or improper lubrication. Nicks can lead to increased friction, reduced bearing performance, and ultimately, premature failure of the bearing. Therefore, nicks are a type of defect that can appear on bearings as a result of bearing parts striking together.

A jet engine uses a gas-driven turbine wheel to drive its compressor. This means that the turbine wheel is powered by the flow of gas, which in turn drives the compressor. This design allows the engine to generate the necessary power and compression for the combustion process, which ultimately propels the aircraft forward. The other options mentioned in the question, such as turbo-superchargers and jet nozzles, are not directly related to the mechanism of driving the compressor in a jet engine.

The reduction geartrain is responsible for reducing the engine rotor speed to the required revolutions per minute (rpm) for accessories. It is a system of gears that work together to decrease the speed and increase the torque of the engine, allowing it to power various accessories efficiently.

Newton's third law of motion states that for every action, there is an equal and opposite reaction. This means that whenever an object exerts a force on another object, the second object exerts an equal and opposite force back on the first object. This law explains the relationship between the forces acting on two interacting objects, emphasizing that the forces are always equal in magnitude and opposite in direction.

Pressure pulsations reduce the efficiency of a centrifugal compressor. When there are fluctuations in pressure, it can cause uneven loading on the impeller blades, leading to vibration and reduced performance. This can result in decreased efficiency and potentially damage the compressor components. Therefore, pressure pulsations are a condition that negatively affects the efficiency of a centrifugal compressor.

The correct answer is internal passages. Internal passages are the channels within the T700 engine accessory gearbox (AGB) that allow oil and fuel to flow through the engine. These passages are located inside the gearbox and are designed to ensure the proper lubrication and fuel supply to the engine components.

A divergent duct is designed to gradually increase the cross-sectional area as the gas flows through it. This causes the velocity of the gas to decrease while the pressure increases. This type of duct is commonly used in applications where it is necessary to slow down the flow of a gas and increase its pressure, such as in certain types of exhaust systems or fluid handling systems.

There are three different types of loads that can be imposed on a jet engine bearing.

The F119-PW-100 engine has 24 fuel nozzles mounted on the diffuser case.

The secondary airflow on the F108 engine produces 80% of the total engine thrust.

In a jet engine, the temperature of compressed air needs to be raised in order to increase its energy. This is because the increased temperature allows for better combustion of fuel, resulting in a more powerful and efficient engine. By increasing the energy of the compressed air, the jet engine can produce more thrust and propel the aircraft forward.

The "fir tree" method of attaching turbine blades to the turbine rotor disc is preferred because it can accommodate the temperature differential between the rotor disc and the blades. This method allows for expansion and contraction of the blades due to temperature changes, ensuring a secure and stable attachment.

The fuel control component is responsible for metering the fuel for combustion in an engine. It regulates the amount of fuel that is injected into the combustion chamber based on factors such as engine speed and load. This ensures that the engine receives the correct amount of fuel for efficient and effective combustion.

The T700 engine's modular concept enables the replacement of specific subsystems rather than the entire engine. This means that if a particular subsystem is damaged or needs maintenance, it can be easily replaced without having to replace the entire engine. This modular approach allows for more efficient and cost-effective maintenance, as well as reducing downtime for the engine.

The F108 accessory gearbox (AGB) is a component of an aircraft engine that houses various accessories. The integrated drive generator, hydraulic pump, and fuel pump are all accessories that can be found on the AGB. However, the augmentor pump is not typically found on the AGB.

The most frequently used method of attaching turbine blades to the turbine rotor disc is by using a series of grooves or notches broached in the rim of the disc. This method provides a secure and reliable connection between the blades and the disc, ensuring that they do not detach during operation. The grooves or notches allow for easy installation and removal of the blades when necessary. This method is widely used in turbine systems due to its effectiveness and practicality.

The correct answer is Diffuser. In a T56 turboprop engine, the diffuser is responsible for dispersing the compressed air from the compressor section and directing it to the combustion chambers. The diffuser helps to slow down and diffuse the high-speed, high-pressure air coming from the compressor, preparing it for combustion in the combustion chambers. This ensures efficient and controlled combustion within the engine.

The most chemically correct ratio for burning fuel in a combustion chamber is 15:1. This means that for every 15 parts of air, there is 1 part of fuel. This ratio ensures that there is enough oxygen present in the combustion chamber to completely burn the fuel, resulting in efficient and clean combustion. A ratio of 10:1 or 10:4 would result in an excess of fuel, leading to incomplete combustion and the production of pollutants.

The correct answer is inside the fan inlet guide vane case at the 5:30 position. This is where the total temperature sensor (Tt2) is located on a F119-PW-100 engine.

The correct answer is "mainframes." In F108, structural rigidity is achieved by having only two main structures called mainframes. These mainframes are responsible for providing the necessary strength and stability to the structure. Having a short length also contributes to the overall rigidity of the structure.

The air temperature of a jet engine gradually rises across the compressor to the diffuser outlet as a result of compression. As the air passes through the compressor, it is compressed and its pressure and temperature increase. This is because the compressor squeezes the air, reducing its volume and increasing its density. This compression process causes the air temperature to rise. Therefore, the correct answer is compression.

The low-pressure turbine (LPT) shaft assembly connects the fan shaft with the LPT rotor. This means that the LPT rotor is the component that is connected to the fan shaft through the LPT shaft assembly.