What is a hydromechanical fuel control?

What is a hydromechanical fuel control?

Types of fuel control units Hydromechanical: A combination of a flyweight governor and several sensors including compressor discharge pressure, burner can pressure, and exhaust pipe pressure. In some cases the engine’s fuel pump is integrated in to the fuel control.

What is hydromechanical unit?

The hydromechanical Unit (HMU) supplies the injectors with fuel at a pressure which is regulated by such factors as compressor output pressure(P3), compressor temperature(T2), the position of the engine power and condition levers on the flight deck and gas-generator speed(Ng).

What is the type fuel control unit used on the gas turbine engine?

A fuel control system for a gas turbine engine has a main metering valve which is positioned by a servo pressure signal controlled by a pilot valve. The pilot valve is responsive to compressor pressures within the engine and also to the operating position of the main metering valve.

What is the primary purpose of fuel control?

The main task of the engine and fuel control system is the metering of the fuel flow to the combustion chamber under the operating conditions of steady state, acceleration and deceleration. The system must achieve this with the aim to keep the engine on the thrust level demanded by the pilot.

What are the two modes of combustion?

The Combustion Modes The combustion process occurs in two modes: Flaming. Non-flaming, smouldering or glowing embers.

How the electronic control system works in the engine?

Fundamentally, the engine ECU controls the injection of the fuel and, in petrol engines, the timing of the spark to ignite it. It determines the position of the engine’s internals using a Crankshaft Position Sensor so that the injectors and ignition system are activated at precisely the correct time.

What are the 4 components of fire?

Oxygen, heat, and fuel are frequently referred to as the “fire triangle.” Add in the fourth element, the chemical reaction, and you actually have a fire “tetrahedron.” The important thing to remember is: take any of these four things away, and you will not have a fire or the fire will be extinguished.

What are the 4 products of combustion?

Products of Combustion

• Carbon Dioxide.
• Carbon Monoxide.
• Sulfur Dioxide.
• Nitrogen Oxides.
• Lead.
• Particulate Matter.

What is the function of electronic control unit?

An electronic control unit (ECU) is a small device inside a vehicle that controls one or several electrical systems in that vehicle. It tells electrical systems what to do and how to operate. ECU’s core is a microcontroller and it is controlled by embedded software.

What is the purpose of electronic engine management system?

How an ECU Works? Based on this data input, the ECU precisely calculates and delivers the ideal air-fuel mixture. It also regulates the idle speed of the engine and limits the top speed of a vehicle. This system is also widely referred to as an ‘Electronic Engine Management System’ or the EMS.

How does the hydromechanical fuel control system work?

Hydromechanical Fuel Control System. The basic principle of turbine engine fuel metering is to vary the flow of fuel to the discharge nozzle by maintaining a constant pressure drop across a metering orifice whose area is varied by Pilot’s throttle position and by engine operating condition.

Which is better electronic or hydromechanical fuel system?

Electronic controls can receive more inputs with greater accuracy than hydromechanical controls. Early electronic controls used a hydromechanical control with an electronic system added on the system to fine tune the metering of the fuel. This arrangement also used the hydromechanical system as a backup if the electronic system failed.

How are hydromechanical controls used in turbine engines?

Early electronic controls used a hydromechanical control with an electronic system added on the system to fine tune the metering of the fuel. This arrangement also used the hydromechanical system as a backup if the electronic system failed. [Figure 2-49] Figure 2-49.

What are the functions of the fuel control unit?

During normal engine operation, a remotely mounted electronic fuel control unit (EFCU) (same as an EEC) performs the functions of thrust setting, speed governing and acceleration, and deceleration limiting through EFCU outputs to the fuel control assembly in response to power lever inputs.