RESEARCH GOAL: MICRO TURBINE GENERATOR FOR UAVs• Hybrid energy supply system: battery buffer charged by micro gas turbine• Energy density of up to 1200 kWh/kg due to high kerosene energy density• Flight time increased 4-6 times compared to Lithium Polymer batteries

Development of a 3D Printed

300W Micro Gas Turbine

Turbomachinery and Heat Transfer LaboratoryPhD Student Lukas Badum, Asst. Prof. Beni Cukurel

CHALLENGES AND PROPOSED INNOVATIONSThe main obstacles to successful UMGT development were manufacturingconstraints, heat transfer management and air bearing instability. These willbe overcome by the following innovations:• Additive Manufactured High-Speed Rotors

-> geometrical flexibility, high TIT• Hollow rotor

-> reducing material agglomeration, heat transfer to compressor, turbine surface temperature

• High-speed hybrid ceramic bearings instead of air bearings-> reliability, no whirl instability, high stiffness, off-the-shelf components

Micro Gas Turbine

Electronics Battery Buffer

Fuel Tank

System weight: 200-300g

𝑷𝒆𝒍 = 𝟑𝟎𝟎𝑾

ROTOR ADDITIVE MANUFACTURINGHigh-speed rotors have been manufactured using different materials and

manufacturing technologies:1. Inconel 718: High temperature capable nickel alloy2. Silicon Nitride: Excellent ceramic for temperatures above 1000°C3. Alumina: Easy-to-manufacture ceramic for high temperature applications

REDUCED ORDER ENGINE MODEL

INTERDISCIPLINARYENGINE OPTIMIZATION

Balancingmarks

UMGT Concept

Turbo-machinery

Turbo-machinery

Thermo-dynamic Analysis

Thermo-dynamic Analysis

Stress Analysis

Stress Analysis

Rotor Dynamics

Rotor Dynamics

Heat

Transfer

Heat

Transfer

Generator Design

Generator Design

Porous Combustor

Porous Combustor

SiNi Rotor

Inconel Rotor

Rotor 3D Scan Balanced Rotor

Roller Bearing

Generator Coil

Permanent Magnet + Sleeve

Radial Compressor

Radial Turbine

Fuel Inlet

Porous Media Combustor

Glow Plug

AirAxial Inlet

Hollow Rotor,Internal cooling

6 cmUMGT Concept

Generator: 2D Magnetostatic Model• Solving Laplace’s equation for magnetic

vector potential in polar coordinates:

𝝏𝟐𝑨

𝝏𝒓𝟐+𝟏

𝒓

𝝏𝑨

𝝏𝒓+𝟏

𝒓𝟐𝝏𝟐𝑨

𝝏𝜽𝟐= 𝟎

• Loss modelling• Stator Iron Losses• Copper Losses• Air friction Losses

Rotordynamic Model• Axisymmetric modelling• Bearing stiffness according to manufacturer data

𝑼𝟔

𝑪𝟔

𝑾𝟔

𝜶𝟔

𝜷𝟔𝒎

Compressor and Turbine Models• Meanline design based on non-dimensional parameters• Automatic 3D geometry generation• Loss modelling for efficiency estimation

𝑼𝟒

𝑪𝟒𝑾𝟒

𝜶𝟒

𝜷𝟒,𝒐𝒑𝒕~ − 𝟐𝟎°

𝜷𝟒𝒊𝟒

HIGH SPEED TESTING AND MODEL VALIDATION• Successful testing up to design speed of 500,000 rpm (cold gas)• Validation of component efficiency, heat transfer models

RotorBearing Casing Turbine ScrollMCR

Radial Turbine Velocity Triangles

Resulting Magnetic Field

NEXT STEPS• Finalize engine model• Hot gas testing• Prototype design and testing