1. Conferenza del Dipartimento DIITET 26 e 27 maggio 2014 Romeo Bernini IREA Il progetto Safuel (Safer Fuel Systems) C ONSIGLIO N AZIONALE DELLE R ICERCHE 26 e 27 Maggio, 2014 Convegno del Dipartimento di Ingegneria, ICT e Tecnologie per l’Energia e i Traporti

2. Conferenza del Dipartimento Roma, 26 e 27 maggio 2014 Introduction © Copyright SAFUEL Consortium

3. Conferenza del Dipartimento Roma, 26 e 27 maggio 2014 SAFUEL Project © Copyright SAFUEL Consortium

4. Conferenza del Dipartimento Roma, 26 e 27 maggio 2014 Rationale © Copyright SAFUEL Consortium

5. Conferenza del Dipartimento Roma, 26 e 27 maggio 2014 Objectives © Copyright SAFUEL Consortium

6. Conferenza del Dipartimento Roma, 26 e 27 maggio 2014 © Copyright SAFUEL Consortium  Realize a new metal-free fiber optic level sensor with comparable performances with traditional Jet-Fuel Level sensors. IREA Objectives Main critical requirements  No sensor degradation from -55°C to +70°C.  Correct operation and no degradation with Vibration 10-2000 Hz 14Grms.  The sensor shall operate correctly and not be damaged when partially or totally exposed to presence of condensed water on its surface.  The sensor shall operate with an optical power not exceeding 35mW.  The sensor shall measure the height of fuel with following accuracy: ±1.5mm when tank empty up to ±3mm when tank is full.  No calibration on A/C allowed.  Particular installation constraints on sensor shall be identified (e.g. volume, installation angle, clearance to structure, bonding to structure…).  The jet fuel, depending on the type and/or the producer, exhibits different refractive index value that ranges from about 1.432 of Sasol fuel to about 1.455 of conventional fuels, depending on density.

7. Conferenza del Dipartimento Roma, 26 e 27 maggio 2014 © Copyright SAFUEL Consortium  Four sensing configuration have been evaluated  Sensor based on radiation losses  Sensor based on radiation losses TIR  Sensor based on fuel absorption  Sensor based on floating mirror  Three distributed interrogator have been tested -Photon-counting Optical Time Domain Reflectometry (PC-OTDR) -Optical Frequency Domain Reflectometry (OFDR) -Optical Time Domain Reflectometry (OTDR) Sensing principle selection  Sensing mechanism that are insensitive to temperature and to the refractive index (Bragg grating, interferometers, …) and more in general that don’t require particular compensations in order to increase the fail safety of the system. Sensing principles

8. Conferenza del Dipartimento Roma, 26 e 27 maggio 2014 © Copyright SAFUEL Consortium Conventional TIR sensor are unable to distinguish fuel from water Fiber optic input Fiber optic output TIR Sensors

9. Conferenza del Dipartimento Roma, 26 e 27 maggio 2014 © Copyright SAFUEL Consortium Sensor Design parameters: Prism angle 60° Refractive index n=1.59 Incident angle 60° Air TIR angle 50° Water TIR angle 54° Fuel TIR angle 65° With a suitable choice of the TIR angle the sensor is sensitive to the fuel and insensitive the water. Novel TIR Sensor design

10. Conferenza del Dipartimento Roma, 26 e 27 maggio 2014 © Copyright SAFUEL Consortium The sensor is insensitive to the water but it works with any jet fuel Novel TIR Sensor design

11. Conferenza del Dipartimento Roma, 26 e 27 maggio 2014 © Copyright SAFUEL Consortium TIR Sensor prototype Single Sensor Sensor multiplexing

12. Conferenza del Dipartimento Roma, 26 e 27 maggio 2014 © Copyright SAFUEL Consortium TIR OTDR Measurements

13. Conferenza del Dipartimento Roma, 26 e 27 maggio 2014 © Copyright SAFUEL Consortium Optical Power Response vs Liquid Level

14. Conferenza del Dipartimento Roma, 26 e 27 maggio 2014 © Copyright SAFUEL Consortium Optical Power Response vs Liquid Level

15. Conferenza del Dipartimento Roma, 26 e 27 maggio 2014 © Copyright SAFUEL Consortium Jet-Fuel vs Water Detection

16. Conferenza del Dipartimento Roma, 26 e 27 maggio 2014 © Copyright SAFUEL Consortium Prototype under construction

17. Conferenza del Dipartimento Roma, 26 e 27 maggio 2014 © Copyright SAFUEL Consortium Thank you