Piezoelectric actuation of an aero engine fuel metering valve

Research output: ThesisDoctoral Thesis

Abstract

Servo valves are used in a broad variety of flow modulation applications. In the field of aerospace, servo valves are used in aero engines to meter fuel flow. The existing valves are labour intensive to manufacture and highly optimised such that to achieve improvements in performance requires a novel design. This research investigates smart material actuators and valve concepts. Specifically, a prototype pilot stage nozzle flapper valve is developed for the purpose of actuating a main stage spool. The typical nozzle flapper type servo valve uses a torque motor to actuate the flapper. In this research project, the torque motor has been substituted for two piezoelectric ring bender actuators. A novel mounting mechanism has been developed to secure the ring benders within the valve. Analytical and finite element models have been made to understand the displacement mechanism of a ring bender and the effects of the mount on the displacement and force from a ring bender, and the results were compared with
experiment. The mounting stiffness at the inner and outer edges was found to decrease the displacement of the ring bender and it was found that the stiffness of the mount at the outer edge has a greater negative effect on displacement than the stiffness of the mount at the inner edge.
The displacement of a ring bender was tested across the operational temperature range of an aero engine. It was found that the displacement of the ring bender is reduced at low temperatures and increases at high temperature. The variation of stiffness of the elastomeric mount was also tested with temperature and it was found that the displacement of a ring bender is significantly reduced when the mounting elastomer approaches its glass transition temperature.
A prototype valve was built to test the pressures and flows that could be achieved at two control ports by using a ring bender as actuator. A single ring bender and two ring benders, mounted in tandem to provide redundancy, have been tested. An analytical model was developed and the predictions are compared with experimental results for pressures and flow. The full stroke of the valve was 300m when mounted and reduced to 150m when mounted in tandem with an inactive ring bender. The hysteresis of the valve is +/-10%. The pressures and flow at and between the control ports of the valve are consistent with the predictions.
LanguageEnglish
QualificationPh.D.
Awarding Institution
  • University of Bath
Supervisors/Advisors
  • Plummer, Andrew, Supervisor
  • Bowen, Christopher, Supervisor
  • Johnston, David, Supervisor
Award date27 Jun 2017
StatusPublished - 2017

Fingerprint

Mountings
Stiffness
Engines
Torque motors
Actuators
Nozzles
Temperature
Reels
Intelligent materials
Elastomers
Redundancy
Hysteresis
Analytical models
Modulation
Personnel
Experiments

Keywords

  • Piezoelectric
  • actuation
  • aero-engine
  • aero engine
  • fuel metering
  • gas turbine
  • ring bender
  • valve
  • servo valve
  • servovalve
  • temperature
  • mounting
  • elastomers
  • analytical model
  • FE model
  • round bender
  • bimorph
  • free displacement
  • blocking force

Cite this

Piezoelectric actuation of an aero engine fuel metering valve. / Bertin, Michael.

2017. 201 p.

Research output: ThesisDoctoral Thesis

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title = "Piezoelectric actuation of an aero engine fuel metering valve",
abstract = "Servo valves are used in a broad variety of flow modulation applications. In the field of aerospace, servo valves are used in aero engines to meter fuel flow. The existing valves are labour intensive to manufacture and highly optimised such that to achieve improvements in performance requires a novel design. This research investigates smart material actuators and valve concepts. Specifically, a prototype pilot stage nozzle flapper valve is developed for the purpose of actuating a main stage spool. The typical nozzle flapper type servo valve uses a torque motor to actuate the flapper. In this research project, the torque motor has been substituted for two piezoelectric ring bender actuators. A novel mounting mechanism has been developed to secure the ring benders within the valve. Analytical and finite element models have been made to understand the displacement mechanism of a ring bender and the effects of the mount on the displacement and force from a ring bender, and the results were compared withexperiment. The mounting stiffness at the inner and outer edges was found to decrease the displacement of the ring bender and it was found that the stiffness of the mount at the outer edge has a greater negative effect on displacement than the stiffness of the mount at the inner edge.The displacement of a ring bender was tested across the operational temperature range of an aero engine. It was found that the displacement of the ring bender is reduced at low temperatures and increases at high temperature. The variation of stiffness of the elastomeric mount was also tested with temperature and it was found that the displacement of a ring bender is significantly reduced when the mounting elastomer approaches its glass transition temperature. A prototype valve was built to test the pressures and flows that could be achieved at two control ports by using a ring bender as actuator. A single ring bender and two ring benders, mounted in tandem to provide redundancy, have been tested. An analytical model was developed and the predictions are compared with experimental results for pressures and flow. The full stroke of the valve was 300m when mounted and reduced to 150m when mounted in tandem with an inactive ring bender. The hysteresis of the valve is +/-10{\%}. The pressures and flow at and between the control ports of the valve are consistent with the predictions.",
keywords = "Piezoelectric, actuation, aero-engine, aero engine, fuel metering, gas turbine, ring bender, valve, servo valve, servovalve, temperature, mounting, elastomers, analytical model, FE model, round bender, bimorph, free displacement, blocking force",
author = "Michael Bertin",
year = "2017",
language = "English",
school = "University of Bath",

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TY - THES

T1 - Piezoelectric actuation of an aero engine fuel metering valve

AU - Bertin,Michael

PY - 2017

Y1 - 2017

N2 - Servo valves are used in a broad variety of flow modulation applications. In the field of aerospace, servo valves are used in aero engines to meter fuel flow. The existing valves are labour intensive to manufacture and highly optimised such that to achieve improvements in performance requires a novel design. This research investigates smart material actuators and valve concepts. Specifically, a prototype pilot stage nozzle flapper valve is developed for the purpose of actuating a main stage spool. The typical nozzle flapper type servo valve uses a torque motor to actuate the flapper. In this research project, the torque motor has been substituted for two piezoelectric ring bender actuators. A novel mounting mechanism has been developed to secure the ring benders within the valve. Analytical and finite element models have been made to understand the displacement mechanism of a ring bender and the effects of the mount on the displacement and force from a ring bender, and the results were compared withexperiment. The mounting stiffness at the inner and outer edges was found to decrease the displacement of the ring bender and it was found that the stiffness of the mount at the outer edge has a greater negative effect on displacement than the stiffness of the mount at the inner edge.The displacement of a ring bender was tested across the operational temperature range of an aero engine. It was found that the displacement of the ring bender is reduced at low temperatures and increases at high temperature. The variation of stiffness of the elastomeric mount was also tested with temperature and it was found that the displacement of a ring bender is significantly reduced when the mounting elastomer approaches its glass transition temperature. A prototype valve was built to test the pressures and flows that could be achieved at two control ports by using a ring bender as actuator. A single ring bender and two ring benders, mounted in tandem to provide redundancy, have been tested. An analytical model was developed and the predictions are compared with experimental results for pressures and flow. The full stroke of the valve was 300m when mounted and reduced to 150m when mounted in tandem with an inactive ring bender. The hysteresis of the valve is +/-10%. The pressures and flow at and between the control ports of the valve are consistent with the predictions.

AB - Servo valves are used in a broad variety of flow modulation applications. In the field of aerospace, servo valves are used in aero engines to meter fuel flow. The existing valves are labour intensive to manufacture and highly optimised such that to achieve improvements in performance requires a novel design. This research investigates smart material actuators and valve concepts. Specifically, a prototype pilot stage nozzle flapper valve is developed for the purpose of actuating a main stage spool. The typical nozzle flapper type servo valve uses a torque motor to actuate the flapper. In this research project, the torque motor has been substituted for two piezoelectric ring bender actuators. A novel mounting mechanism has been developed to secure the ring benders within the valve. Analytical and finite element models have been made to understand the displacement mechanism of a ring bender and the effects of the mount on the displacement and force from a ring bender, and the results were compared withexperiment. The mounting stiffness at the inner and outer edges was found to decrease the displacement of the ring bender and it was found that the stiffness of the mount at the outer edge has a greater negative effect on displacement than the stiffness of the mount at the inner edge.The displacement of a ring bender was tested across the operational temperature range of an aero engine. It was found that the displacement of the ring bender is reduced at low temperatures and increases at high temperature. The variation of stiffness of the elastomeric mount was also tested with temperature and it was found that the displacement of a ring bender is significantly reduced when the mounting elastomer approaches its glass transition temperature. A prototype valve was built to test the pressures and flows that could be achieved at two control ports by using a ring bender as actuator. A single ring bender and two ring benders, mounted in tandem to provide redundancy, have been tested. An analytical model was developed and the predictions are compared with experimental results for pressures and flow. The full stroke of the valve was 300m when mounted and reduced to 150m when mounted in tandem with an inactive ring bender. The hysteresis of the valve is +/-10%. The pressures and flow at and between the control ports of the valve are consistent with the predictions.

KW - Piezoelectric

KW - actuation

KW - aero-engine

KW - aero engine

KW - fuel metering

KW - gas turbine

KW - ring bender

KW - valve

KW - servo valve

KW - servovalve

KW - temperature

KW - mounting

KW - elastomers

KW - analytical model

KW - FE model

KW - round bender

KW - bimorph

KW - free displacement

KW - blocking force

M3 - Doctoral Thesis

ER -