Micro gas turbine design for turbojet, turboshaft, and APU applications with CNC/3D printing guidance
Engine Configuration
✓ RPM within limit (max 150,000)
✓ TIT within material limits
Compressor Design
Tip Speed: 314 m/s (M0.92)
Stress SF: 2.1 | Temp Margin: 204°C
Turbine Design
Tip Speed: 288 m/s
Stress SF: 1.8 | Temp Margin: 180°C
Manufacturing Analysis
CNC Machining
366 hrs
$403147
3D Printing
340 hrs
$290257
Recommendations:
• Compressor: CNC preferred
• Turbine: DMLS/SLM 3D printing
• Combustor: Sheet metal forming or 3D printed with cooling channels
Temperature & Pressure Through Engine
Compressor Performance Map
📋 Engine Specification
TURBOJET ENGINE SPECIFICATION
Type: Single-stage micro turbojet for RC/UAV
Design RPM: 100,000 RPM
TIT: 800°C
COMPRESSOR:
Diameter: 60mm, 12 blades
Material: Aluminum 7075-T6 (Compressor only)
Pressure Ratio: 1.43:1
TURBINE:
Diameter: 55mm, 17 blades
NGVs: 11
Material: Inconel 718 (Nickel Superalloy)
PERFORMANCE:
Thrust: 264.6 N
Mass Flow: 228.5 g/s
Fuel Flow: 17387 g/h
Efficiency: 12.6%
MANUFACTURING:
Method: CNC
Est. Time: 366 hrs
Est. Cost: $403147
🛠️ Manufacturing Guidelines
CNC Machining:- 5-axis required for impeller blades
- EDM for thin turbine blade profiles
- Surface finish Ra < 1.6μm for aero surfaces
- Balancing to G2.5 or better
Metal 3D Printing (DMLS/SLM):- Layer thickness: 20-50μm
- HIP treatment recommended for Inconel
- Support removal from internal passages
- Post-machining critical surfaces
Critical Tolerances:- Shaft bore: H7 (±0.01mm)
- Blade tip clearance: 0.2-0.5mm
- Bearing seats: h6 (±0.008mm)
- Balance: <0.5 g-mm per plane