Static test of the Snark VTVL Engine

On 8th June 2016 we carried out another vertical static test of the Snark rocket engine on the “Gryoc” VTVL (Vertical Take-off, Vertical Landing) technology demonstrator vehicle. The propellants are nitrous oxide (N2O) and isopropyl alcohol (IPA). A number of different throttle settings were used, peak thrust being around 300N. The purpose of this test was to obtain high-fidelity data about engine performance and hydraulic characteristics of the injector and throttle valves. This data will allow the throttle feedback loop to be tuned properly. In this test, the gimbal actuators have been temporarily removed and the engine mounted on its own load cell to get better thrust data. Video of the test is available on our YouTube channel here

Airborne Engineering begins testing advanced rocket engine for Reaction Engines

STOIC Engine Test Rig

Airborne Engineering has begun testing an innovative new rocket engine on behalf of customer Reaction Engines Limited. The engine, code-named “STOIC”, has been developed by Reaction Engines as part of their Advanced Nozzle Programme in order to test important technologies for the SABRE engines that will propel the Skylon spaceplane. Skylon’s SABRE engines need to operate in both air-breathing and rocket modes. STOIC is capable of demonstrating these two modes and the smooth transition from one to the other. The STOIC test programme will also allow Reaction Engines to refine their computer models of the internal aerodynamics of the SABRE engine.

Dr Helen Webber, Reaction Engines’ Project Lead for the Advanced Nozzle Programme, commented: “This experimental engine is an important step into a new era of propulsion and space access. We are using it to test the aerodynamics and performance of the advanced nozzles that the SABRE engine will use, in addition to new manufacturing technologies such as our 3D-printed injection system. The testing of new propulsion technology has required close work with our partners at Airborne Engineering, in order to make a test rig that can simulate the unique and demanding range of conditions required to put this engine through its paces. Despite being much smaller than SABRE, this engine is still the largest bi-propellant engine to be tested at Westcott for over thirty years, and it is exciting to see the resurgence of Westcott as the centre for UK rocket propulsion research and development. The next few months will see us running the engine for much longer periods in order to explore the transition between the air-breathing and rocket modes of the SABRE’s flight – an important and challenging part of powering Skylon into space.”

STOIC engine represents a big advance in engine technology compared to previous test programmes conducted by Airborne Engineering and Reaction Engines. STOIC features a 3D-printed injector, water cooling and automated throttle control of propellants. In order to test STOIC, Airborne Engineering has had to build a completely new test rig at its J2 facility at Westcott. The new test rig features innovative flow-control valves developed in-house by Airborne, capable of accurately reproducing almost any desired profile of propellant mass-flow despite constantly changing inlet pressures and temperatures. A new modular data acquisition system, also developed in-house by Airborne Engineering, logs over one hundred channels of data on the STOIC test rig. The data acquisition system also features automatic generation of post-firing data reports so that Reaction Engines can examine the performance of the engine within minutes of a test.

The Reaction Engines press release for STOIC is available here: 2015-06-11_STOIC_Firing_Release_PUBLIC (PDF.)

Snark engine vertical test

Vertical static test of Snark engine

On the 29th June 2012, Airborne Engineering carried out the first vertical static test of it Snark rocket engine. The Snark bi-propellant rocket engine burns nitrous oxide and isolpropyl alcohol and is part of an internal R&D programme to showcase the capabilities that the company can offer, as well as generating spin-off technologies.

A video of a subsequent test is available here.

Snark Throttle Test

Static test of the “Snark” Variable-Thrust Bi-Propellant Liquid Rocket Engine by Airborne Engineering Limited.

This montage shows the engine operating at three different thrust levels (lowest at top of picture, highest at bottom). Notice how the mach-diamonds move apart as the thrust is increased.

The black wire hanging down near the flame is from the ignition system, the end of which is spat out from the nozzle at start-up. The bracket it is wrapped around is one of the mounts for the linear actuators which are used to steer the engine when it is attached to a rocket.

The spark trails visible near the flame are caused by the ablative combustion chamber liner.

The propellants are nitrous oxide and isopropyl alcohol. The maximum thrust level is 300N. Throttle ratios of up to 5:1 have been demonstrated without the engine showing any signs of instability. In this test, the throttle valves were digitally controlled using an Arduino microcontroller.

The Snark engine is of a modular design which can be configured for different thrust ranges. The example shown here is at the low end of the thrust spectrum. Thrust levels up to 2KN are possible in this form-factor (3 inch diameter chamber) by using a larger nozzle and injector.