Rocket engine cryogenic valve.

A high pressure valve for future high performance rocket engines.

Introduction The Astrium space propulsion centre in Ottobrunn, Germany, has commenced development on a new generation of electric motor driven cryogenic valve. This high pressure valve is designed for use with future high performance cryogenic rocket engines such as the Vinci rocket engine.

HP Cryogenic propellant valve

Vinci engine

Vinci is an expander cycle engine designed for the future cryogenic upper stage of Ariane 5. For the Vinci application, the valve will be used as a shut-of valve for LOX and LH2 propellants. More information on the Vinci engine can be found in a PDF file.

The high pressure cryogenic valve has undergone a number of tests at the Lampoldshausen Test centre, including verification, life and operational testing. During the course of these tests, the valve's features and performance was found to be ideally suited for cryogenic fluid handling and test facility applications.

Features
The high pressure cryogenic valve includes the following features:
Coaxial flow poppet valve.
Actuation forces virtually independent of line pressure.
Spring loaded seal force to eliminated thermal stresses.
Seat of soft PTFE material.
Easy maintenance.
Cone shaped inlet poppet adaptable to any regulation behaviour.
Electric servo motor for any predefined stroke.
Electric drive will hold the valve position in the event of power loss.

16 pre-set positions defined with the variable parameters of:
Stroke.
Piston force.
Acceleration and deceleration.
Piston speed.

Valve Design and Heritage
The valve design and heritage is based on existing flight proven cryogenic valves designed, developed and produced at the Ottobrunn facility. These valves are used on the Ariane 5 core stage for propellant and pressurant control, as well as main valves for cryogenic rocket engines, such as the HM-7 rocket engine.

The HM-7 engine was developed 30 years ago and has reliably served Ariane's 1 through 4 since 1979. Such is the reliability of the HM-7 engine, that it will continue to be used during the future evolution of Ariane 5.

Design Description Main Parameters: Medium: Max. Pressure: Temperature: Flow Path Diameter: Flow Coefficient: Leakage: Seat: Drainage: External: Min. Response Time: LOX, LH2, LN2, GHe 250 bar - dp across valve seat 20 - 300 K 50 mm 5.3 * 10 EXP 5 1/m4 < 100 scc/s < 100 scc/s < 10-3 scc/s

Section through valve enlarge

Performance
The valve performance is precisely matched to the requirements for the VINCI engine, namely:

Low pressure shut-off valve for fill and drain functions.
Low pressure shut-off valve in feed pipes.
High pressure valve as thrust chamber flow control valve.
High pressure valve as turbine bypass regulation valve.
Design is in accordance to Customer-specification for VCO and VCH.

The valve pre-qualification tests will be performed in the frame of Vinci thrust chamber tests (passenger tests). For the purpose of pre-qualification tests, the valve will be equipped with a 'battleship' drive motor.

Valve battleship configuration enlarge

Motor programmable via serial interface only.

Telemetry:
- analogue position indicator
- piston force sensor

Verification Tests Leak tests up to 100 bar. Functional test for VINCI injector Spray test with LN2 at 5 bar.   Lifetime Tests 2000 actuation's with 2 valves at ambient temperature and at 80 K. Valve life cycle test at 80 K with LN2 and 5000 actuation's.   Operational Test with Vinci thrust chamber Cold flow transient tests with LH2 at 4 bar pressure. Ignition tests with LOX and LH2. Ramp-up tests up to 90 bar pressure. Stability tests.

enlarge enlarge

Contact for Further Information

General information on the cryogenic valves used on the Ariane 5 core stage are also available in a PDF file.