Skip to main content

Valves for OiL regulaTion with High AccuracY and REliability

Periodic Reporting for period 1 - VOLTAYRE (Valves for OiL regulaTion with High AccuracY and REliability)

Reporting period: 2019-03-01 to 2020-05-31

The VOLTAYRE project responds to a new feature needed for future engines with very high dilution rates such as the Ultra High Bypass Ratio being developed by Safran Aircraft Engines. To reduce kerosene consumption, the engine input blower will run at a different speed than the main rotor, allowing on the one hand to increase the secondary air flow provided by the blower and on the other to improve the efficiency of the different compression stages. The blower and compressors work at their best performance point regardless of the flight phase. For both mobiles to rotate at a different speed it is necessary to place an epicycloidal train between the blower and the rotor.
Depending on the flight phase, the UHBR calculator requires the VOLTAYRE servo-valve to adjust the lubrication flows sent to the engine, the epiccycloidal train and the tank.

The objectives of VOLTAYRE is to design & manufacture an innovative high flow direct drive oil valve, and qualify this valve up to TRL 5 level. This valve will be able to meter accurately and split the flows coming from the pump to the gearbox and to the engine, whereas the extra flow will return to the tank. Our product will also communicate to the FADEC an image of the delivered flows to close the loop and to accurate metering.

VOLTAYRE proposal is based on the upsizing of our patented FACT electronic free low energy limited angle torque motor that will require at least two extra patents. This torque motor will be able to provide high torque, high displacement, high ageing stability, without dynamic seals which is able to direct drive a spool that will meter and split an oil flow of about 13000l/h@ 70 bar (57GPM@1000psi). This Valve is coupled with an hydromechanic three-way delta pressure regulator mounted together with the others units on a aluminium manifold.
The Voltayre project started with the kick-off meeting with the topic manager on March 1st, 2019. The reception in advance of the first specification version initiated the specification analysis work. However, we fell behind in the first phase due to the arrival of funding 15 days after the start of the project on the one hand and on the other hand by the fact that the topic manager took a long time to respond to the specification clarifications that we asked him at the beginning of the project. At the end it was difficult to have all the topic manager auditors during summer. As a result, the PDR was delayed by a month and a half.
We were then able to work on different equipment architectures that were able to meet the need. Finally, the architecture chosen is not the one proposed in Appendix 1 but another one that allows to integrate a Safran patent on the distribution of oil flows between the engine and the RGB. An additional bypass function has been added in case of valve blockage which also allows the engine to supply oil in cold conditions.
Once the architecture was selected, we worked on the design and preliminary sizing of the equipment. This resulted in a first version representing not a 1D model under Amesim to validate the functional part of the equipment and by a digital CAD model to validate the integration on the engine. This digital CAD model has been available as a physical model in 3D plastic printing.
The PDR milestone was successfully passed in September 2019.
In the critical design phase, we were able to refine the design and modelling of the equipment. We have been working on the accuracy of the ∆P-sensor to ensure the best possible accuracy. Indeed, the specified flow range is larger than expected. As a result, in low flow ranges, the accuracy is greater than the specification. From the data of the topic manager we were able to size the different points of operation of the duty cycle. We also worked to determine the cases of failures and the response of the equipment to these failures. The critical design phase was interrupted by the health crisis linked to COVID 19. We had done the main tasks of the work package. We are ready to deliver a new version of the more accurate 1D model as well as a more advanced 3D CAD model with a digital validation (mechanical, CFD and magnetic) of its various parts.
The CDR milestone was succesfully passed in July 2020.
The objective of the project is to develop a 4-ways servo-vanne with a more electric architecture, without hydraulically amplified control (servovalve). This architecture allows a functioning in spite of the very viscous oil in cold weather but also a reduction of the risk of external leakage thanks to a reduction in the number of waterproofing.
Our servo-valve will also be electronically free to operate with hot oil in a warm environment without reliability degradation.
It will more accurately enslave the dosed flows by directly measuring depressogenous flow per flow meter, instead of an indirect measure of position.


To meet the need of the Voltayre project while maintaining its development capacity for its current customers we recruit 3 additional employe two engineers: simulation and test bench and a designer. FACT's workforce has grown from 4 to 7 in 2019.

Due to Voltayre impact we have increase our request for quotation during 2019 and begining of 2020. Our Direct Drive Valve technology and the first results on size M torque moteur through Voltayre project interested a large number of customers: French, European and also American. We were able to offer our equipment for several types of aircraft system, fuel, oil, air, hydrogen.
We won a first contract with Safran Aerosystems (Roche la Molière) on a pre-study of a Nitrogen flow control valve (based on our DDV technology) for the fuel tank inerting system.
We have also interested other sectors, particularly around fuel cell applications for aeronautic and heavy transport.
First draft picture of the equipment PDR level
First 3D printing Mock-up of Voltayre (PDR level)