The LR-100C Power Plant Gas Turbine Engine
Introduction
I’ve always been fascinated and loved jet engines for some reason, even since I was little. To me, they always had a more of a cool-factor compared to reciprocating-piston engines.
However, this cool-factor is not without reason. Turbine engines can be very powerful and efficient. Plus, they have a really awesome spooling sound when they start! In 2018 I decided to try designing my own because I felt I was equipped with enough knowledge on their inner mechanical workings. My first designs were primitive centrifugal turbines similar to those RC planes.
Over time, I got more acclimated to using CAD software and strengthened my manufacturing/DFM knowledge and I also learned more about these combustion engines, so in 2019 I decided to venture into the world of reverse-flow axial gas turbines.
Project Feature List
Axial flow ✓
12 can combustors ✓
4 fuel inlets per combustor ✓
Multiple air taps ✓
2 stage power turbine ✓
7 stage compressor ✘
Inlet guide vanes ✘
Sensor ports ✘
Generator control unit mounting ✘
Simulate engine flow, compression, and combustion ✘
Actually fabricating it? ✘
“The engines don't move the ship at all; the ship stays where it is and the engines move the universe around it“
Engine Insights
The Combustion Chamber
The LR-100C is a can type combustion chamber engine. It features 12 independent combustion chambers, each with its own igniter, fuel inlets, air taps, and two crossfire tubes linking it to the 2 adjacent combustors. The primary materials will be various stainless steels.
Turbine Stages
The LR-100C will feature a 2 stage turbine with active air-cooling via internal cooling channels in the shaft assembly. It requires active cooling because the turbine will often run the hot section components above, at or near their melting point. Without proper cooling, this extremely high temperature can cause rotor damage or complete system failure. At high RPMs, a structural failure in the kinetic geometry can result in divergence of the rotor material. In other words, molten shrapnel will fly at hundreds of kilometres per hour in every direction!
Turbine Lower Shaft Assembly
The lower shaft assembly is contained in the hot section of the engine. It features internal cooling air passages and ducting in order to redirect colder compressor discharge air to the turbine and stator blades. It also has dual axial bearings for smooth movement and honeycomb-labyrinth seals to prevent significant air leakage from the gaps between the rotor-stator complex into the upper engine and bearings.
FAQ
Why am I designing and constructing a turbine engine?
To be honest, doing this is actually fun for me and it is a great metric of my own abilities. Plus, it’s kinda cool to be able to say you have designed you own gas turbine…
How much will this cost?
No idea. I’m expecting to drop at least $100k on this. Whether or not I will ever afford to finish this is a completely different question :D
What materials will be used in the assembly?
So far, here is what is going to likely be used:
High temperature stainless steels for upper compressor, blade hubs, housings, and the shaft
Inconel 600/625 or high-temp stainless steel for all high velocity hot-section components
Aluminum for some external geometries and low-temperature parts
How much will the design change over time?
This turbine’s geometry will constantly change. I may decide to add, change or delete features from the engine. Additionally, simulation results will definitely impact the final design as well as factory/machinist feedback.
11/25/2023: My Inventor License expired several months ago, so now the engine files are imported in SolidWorks.
The issue is however, that I need to remodel everything!
My disappointment is immeasurable, and my dayyear is ruined…
Image credit to my friend Liam
