Liquid oxygen and liquid methane
We want to know whether a liquid methane spray can keep a rotating detonation going. Methane is also what a lot of newer upper stages burn.
Resonance Gen 1
Our first engine: a water-cooled rotating detonation combustor for liquid oxygen and liquid methane, in the 2 kN class. The first firing has to show the wave holding for five seconds after the igniter is off.
Design targets
Performance
- Thrust
- 2 kN class1.55 to 1.82 kN expected
- Chamber pressure
- About 271 psiaDesign target
- Mixture ratio (O/F)
- 3.00Nominal design point
- Detonation hold
- 5 sAfter the igniter is off, within a firing of about 7 s
Geometry
- Channel outer diameter
- 85 mmOuter bore diameter
- Channel gap
- 5.0 mmRadial gap
- Combustor length
- 51 mmInjector face to throat
- Nozzle
- Annular throatCenterbody plug
Systems
- Propellants
- LOX and LCH₄Pressure-fed
- Total propellant flow
- 0.874 kg/s0.655 LOX, 0.218 LCH₄
- Cooling
- Deionised waterOuter wall and centerbody
- Ignition
- Gas torchHydrogen and oxygen, bench-tested first
Layout
The engine design is in review as we talk to manufacturing partners and prepare for testing.
Conceptual section. Proportions and passages are simplified.
- Preliminary
Feeds liquid oxygen and liquid methane into the channel.
A stiff injector: about two-thirds of chamber pressure or more across the plate, at about 271 psia. The finished injector is flow-tested to set its operating pressures.
- Preliminary
The ring the detonation runs around, between the outer wall and the centerbody.
85 mm outer diameter, 5 mm gap.
- Preliminary
Deionised water will cool both walls, from a supply we are building ourselves, for the whole firing of about seven seconds.
Printed copper-alloy bodies with internal cooling passages.
- Preliminary
An annular throat and centerbody plug guide the exhaust out of the engine.
The geometry is under design review.
- Set
Starts combustion so we can study whether the wave keeps going on its own.
A hydrogen and oxygen torch through the chamber wall, to be proved on a bench first.
- Preliminary
Build the electronics for pressure transducers and data acquisition, and help capture high-speed footage of the engine.
High-speed imaging, with thrust and operating-pressure measurements.
Design choices
These are the choices for the first engine.
Pressure-fed
The combustor is the experiment, so the tanks and lines should stay simple.
2 kN class thrust
A compact engine sized for development and testing on a university test stand.
Water-cooled copper walls
Internal cooling channels carry heat away from both walls during firing.
Ignition testing
We will test the igniter on a bench before integrating it with the engine.
Goals for the first firing
Success is the first two. Performance is recorded on every firing but is not a pass mark.
| Result | What it means | How we check |
|---|---|---|
| Show the wave | The detonation keeps going around the channel for at least five seconds after the igniter is off. | High-speed imaging of visible wave behavior. |
| Fire again | The hardware comes out of the whole firing, about seven seconds from start to shutdown, ready to fire again. | Water cooling on both walls, and an inspection of the hardware after every run. |
| Record performance | Thrust, propellant flow and chamber pressure are recorded on every firing. They are data, not a pass mark. | Calibrated thrust stand, propellant flow metering and chamber pressure. |
Steps to the first firing
Each step checks one thing before we start the next.
- 1
Design and review
Finish the first design and get someone else to review the numbers before we build anything.
In progress - 2
Build and inspect
Machine or print the copper hot section and CT-scan the cooling channels.
Next - 3
Cold flow and checkout
Run water and stand-in fluids, then check the valves, sensors, and abort.
Planned - 4
Hot fire
Fire the engine, write down the measurements, and inspect the hardware afterward.
Planned
Work with us
We are looking for students who want to own a part of the engine, and for partners who can help us build and measure it. If you want to join or have any questions, just email us.