DESIGN OF A PULSED JET ACTUATORFOR SEPARATION CONTROL

CEAS Conference 2017 – Bucharest, Oct 16-19

Philipp Schlösser (Airbus Defence and Space GmbH)

Matthias Bauer (NAVASTO)

Separation Control at the Pylon/Wing Junction

Motivation

• Integration of UHBR engines requires larger slat cutouts

reduced high-lift performance

• Relevant (sub-)systems tested in real-size under realistic flow conditions (Ma, Re)

TRL 4 Test

2

single slotted flap

side plates

AFC location

Flow-through UHBR

nacelle

deployed slat

Design of a Pulsed Jet Actuator for Separation Control - CEAS Conference - October 2017

Installation of Pulsed Jet Actuator on WTM

3

Model span: ~6 m

Model chord: ~3.3 m

Actuated span: ~1 m

Design of a Pulsed Jet Actuator for Separation Control - CEAS Conference - October 2017

Pulsed Jet Actuator Design

Two-stage Concept

• Driving/1st stage: fluidic oscillator control signal

• Outlet/2nd stage: fluidic diverter elements generation of pulsed jets

4

Illustration of fluid flow inside acutator

Adapted design for application

at engine/wing junction

2nd stage element

1st stage

Design of a Pulsed Jet Actuator for Separation Control - CEAS Conference - October 2017

Pulsed Jet Actuator Design

Separation Control

• Injection of high-momentum into boundary layer

• Entrainment of high-momentum free-stream fluid

Benefits of pulsed actuation

• Generation of vortical structures

increased mixing rate increased momentum transfer

Benefits of two-stage design

• Efficiency – conversion of total to dynamic pressure is more efficient due to the application of several diverters driven by only one oscillator

• Compactness – driving multiple diverters with one oscillator

• Variability – independent setting of actuation amplitude and frequency

Design of a Pulsed Jet Actuator for Separation Control - CEAS Conference - October 2017 5

Requirements

Design of a Pulsed Jet Actuator for Separation Control - CEAS Conference - October 2017 6

Flow control / physics Model / geometryEnvironment / wind

tunnel• jet velocity / Mach number

• pulsation frequency range

• mass flow rate or outlet slot

dimensions

• number of slots

• geometric jet exit angle

• jet quality criterion

(jet velocity homogeneity)

• location of AFC system integration

• installation space

• interfaces for structure and

pressure supply

• loads on the AFC system

• temperature of ambient

and working fluid

• security factors issued by

the wind tunnel operators

can act as significant cost drivers for

testing and manufacturing!

Design Workflow

Design of a Pulsed Jet Actuator for Separation Control - CEAS Conference - October 2017 7

TheoreticalDesign

• Set approx. dimensions

• Set number of elements

• Estimate dimensions of critical cross-sections

Diverter Design (Outlet Stage)

• Iterative with CFD and experiment

• Use of rapid prototyping (3D-printing)

Oscillator Design and Combination

• Experimental design (CFD uneconomical)

• First full prototype testing

Final Design

• Interfaces (structure, air supply)

• Characterization prior to WTT

Ground Testing of Pulsed Jet Actuator

Prototype Testing

• First investigation of complete system

• Tuning of actuation frequency with variablefeedback length

• First characterization of jets

Final Testing

• Final system including air supply interface for WTT

• Including monitoring system (21 pressure sensors)

• „Calibration“ of system for WT application

Aquired Data

• Mass flow

• Frequency

• Jet Mach numbers (from three-hole probe)

• 21 pressure sensors for monitoring during WTT

8

Final actuator for WTT

Prototype

Design of a Pulsed Jet Actuator for Separation Control - CEAS Conference - October 2017

Ground Test Results

Prototype Testing

• Focus on actuationfrequency by variyingfeedback length

• Frequency decreaseswith length of feedbacklines

• Frequency increases withmass flow

Selection of final design from extrapolated data

Design of a Pulsed Jet Actuator for Separation Control - CEAS Conference - October 2017 9

Ground Test Results

Design of a Pulsed Jet Actuator for Separation Control - CEAS Conference - October 2017 10

Additional feedback length in final design

Frequency and size req‘ satsified!

Ground Test Results

Testing of final actuator

Mach numbers evaluated from three-hole probe

11

Diverter #7

Design of a Pulsed Jet Actuator for Separation Control - CEAS Conference - October 2017

Ground Test Results

Testing of final actuator

Mach numbers evaluated from three-hole probe

• Instants of peak Mach number for each slot

Similar symmetric patterns

High homogenity (𝑀 > 0.8 for large area)

• Mach number histories of two points

Full modulation

12Design of a Pulsed Jet Actuator for Separation Control - CEAS Conference - October 2017

Installation of Pulsed Jet Actuator

• Actuator successfully installed into wind tunnel model

• Testing finished in September 2017

Design of a Pulsed Jet Actuator for Separation Control - CEAS Conference - October 2017 13

Summary

Design of a Pulsed Jet Actuator for Separation Control - CEAS Conference - October 2017 14

Flow control / physics Model / geometryEnvironment / wind

tunnel• number of slots

• geometric jet exit angle

• jet velocity / Mach number

• pulsation frequency range

• mass flow rate

• jet quality criterion

(jet velocity homogeneity)

• location of AFC system integration

• installation space

• interfaces for structure and

pressure supply

• loads on the AFC system

• temperature of ambient

and working fluid

• security factors issued by

the wind tunnel operators

✓Ground Tests ✓

Installation✓

Successful WTT

Thank you for your attention!

15

Partners

Presenter

Philipp Schlösser philipp.schloesser@airbus.com +49 89 607 28606

Co-Author

Matthias Bauer matthias.bauer@navasto.de

Acknowledgement

The work described in this presentation and the research leading to these results have received

funding from the European Community's Seventh Framework Programme FP7/2007-2013,

under grant agreement n° 604013, AFLONEXT project.

Design of a Pulsed Jet Actuator for Separation Control - CEAS Conference - October 2017