ขั้นตอนคอมเพรสเซอร์ (None: Compressor Stage)

What Is a Compressor Stage?

A compressor stage is one compression unit within a jet engine's axial compressor, consisting of a rotating row of airfoils (rotor blades) followed immediately by a stationary row (stator vanes). Each stage incrementally raises air pressure and temperature; modern high-pressure compressors (HPC) stack 8–14 stages to achieve overall pressure ratios of 40:1 or higher before the air enters the combustion chamber.

How It Works

Incoming air from the previous stage (or the engine inlet) enters the rotor row. The rotating blades — shaped like asymmetric airfoils — accelerate the air and add kinetic energy. The downstream stator vanes then convert this kinetic energy into static pressure rise through diffusion, slowing and straightening the airflow to prepare it for the next rotor row.

Each stage achieves a pressure ratio of approximately 1.2:1 to 1.4:1. The cumulative effect through many stages is dramatic: air entering a modern high-pressure compressor at roughly 200 kPa (29 psi) exits at perhaps 4,000–5,500 kPa (580–800 psi) in the most advanced engines. Variable stator vanes on early HPC stages allow the compressor to operate efficiently across a wide range of throttle settings without surge.

Performance Specifications

• Stage pressure ratio: 1.2:1 to 1.4:1 per stage (typical axial)
• Overall HPC pressure ratio: 22:1 (CFM56) to 27:1 (LEAP-1) to 60:1 (GE9X, combined LPC+HPC)
• Stage count: modern LEAP-1B uses 3-stage LPC + 10-stage HPC; GE9X uses 3+10 stages
• Blade tip speed: 300–500 m/s (980–1,640 ft/s)
• Exit air temperature: 600–700°C (1,110–1,290°F) at high-power conditions

Aircraft Examples

• CFM LEAP-1B on the Boeing 737 MAX 8 — 3-stage LPC, 10-stage HPC
• GE9X-105B1A on the Boeing 777X — 3-stage LPC, 10-stage HPC, overall pressure ratio approximately 60:1
• Rolls-Royce Trent 1000 on Boeing 787-9 — 8-stage IP compressor, 6-stage HPC

Compressor efficiency is central to overall engine thermal efficiency; a 1% improvement in compressor polytropic efficiency translates to roughly 0.3–0.5% reduction in specific fuel consumption. Advanced computational fluid dynamics and additive manufacturing have allowed blade profiles of increasing aerodynamic complexity in modern designs.