ห้องเผาไหม้ (None: Combustion Chamber)

What Is a Combustion Chamber?

The combustion chamber — also called the combustor or burner — is the component of a gas turbine engine where high-pressure air from the compressor stages mixes with atomized jet fuel and undergoes sustained combustion. The resulting high-temperature, high-pressure gas stream, reaching 1,600–2,000°C (2,910–3,630°F), is directed into the turbine section to extract work. The combustion chamber must sustain stable combustion across an enormous range of fuel flows while minimizing emissions, pressure loss, and exit temperature distortion.

How It Works

Modern commercial engines use an annular combustor — a single continuous ring-shaped chamber surrounding the engine axis, replacing older can-annular designs. Compressed air enters through the diffuser, where velocity decreases and static pressure rises slightly. Approximately 20–30% of this air enters the primary combustion zone through swirler nozzles surrounding each fuel injector, creating a recirculating vortex that stabilizes the flame. The remainder enters downstream as dilution air, cooling the combustion products to a turbine-safe temperature.

Fuel is atomized by high-pressure fuel injectors (typically 16–24 per engine) into fine droplets, ensuring rapid evaporation and mixing. Igniters — high-energy spark plugs — initiate combustion during start; the flame is self-sustaining thereafter. Two igniters are retained active or armed for relight capability.

Performance Specifications

• Combustor inlet temperature: 600–700°C (1,110–1,290°F)
• Combustor inlet pressure: 3,500–6,000 kPa (510–870 psi) in modern high-pressure-ratio engines
• Gas temperature at combustor exit (TET): 1,600–1,900°C (2,910–3,450°F)
• Combustion efficiency: above 99.9%
• Pressure drop across combustor: 3–5%
• NOx emissions: ICAO CAEP/8 certified engines achieve 45–60% below CAEP/6 limits using lean-burn or TAPS technology

Aircraft Examples

• GE Twin Annular Premixing Swirler (TAPS III) combustor in GE9X on Boeing 777X — NOx 50% below CAEP/6
• CFM LEAP Talon II combustor on Airbus A320neo
• Rolls-Royce Trent XWB lean-burn demonstrator — target 75% below CAEP/6 for UHBR variants

The combustion chamber is subject to the highest sustained temperatures in any engineering system, operating above the melting point of the surrounding nickel superalloy liner (protected by thermal barrier coatings and film cooling). Advances in ceramic matrix composite liner materials and sustainable aviation fuel compatibility are the primary combustor development priorities for the late 2020s.