EOARD AERONAUTICAL

SCIENCES 17 March 2011

Gregg AbateProgram Manager

AFOSR/RSW

Air Force Office of Scientific Research

European Office of Aerospace Research & Development

AFOSR

Distribution A: Approved for public release; distribution is unlimited. 88ABW-2011-0795

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2011 AFOSR SPRING REVIEWEOARD AERONAUTICAL SCIENCES

PORTFOLIO OVERVIEW

NAME: Gregg Abate

Prior experience: • 1987-2001 Aerospace Engineer RW (Basic research on external aero & flt mech)

• 2002-2004 Exchange Engineer (Ernst Mach Institute, Freiburg, Germany)

• 2004-2010 RW (Basic research on MAVs, Chief Engineer for MAVs)

BRIEF DESCRIPTION OF PORTFOLIO:

Identifying world class research in the EOARD area of resposibility

focusing on: aerodynamics (low speed – hypersonic), air breathing

propulsion, aero-structural interaction, air vehicle technologies and

the modelling thereof

LIST SUB-AREAS IN PORTFOLIO:

Aerodynamics, Propulsion, Structural Mechanics, Multi- Disciplinary

Optimization, Flight Controls, Combustion, Thermal Management,

Aeroelasticity, Applied Mathematics that support high-order methods

for CFD

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EOARD Aeronautical Sciences

• Technologies that enable flight (in air)!

• Where are the challenges at this time?

• Low Reynolds number

aerodynamics

• Membrane wings

• Flapping flight

• Biological Inspiration

• Hypersonic aerodynamics

• Heat transfer

• Propulsion

• BL Transition

• Shock-BL interaction

Very low/slowAdv. Technologies of

“conventional” aircraft

• Morphing

• Adv. Aero/Structures

• Adv. Propulsion

Flight Control

High Order methods for CFD

Modeling & Simulation

Multidisciplinary Optimization (MDO)

Very high/fast

O (10K) Reynolds number

0 Mach

O (10M)

5+

Delfly II – TU-Delft

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Portfolio Philosophy

• Leveraging European Research Excellence in:

– Low Reynolds number fluid dynamics

– Fundamental research in:

• Plasma & MHD

• Hypersonics

• Propulsion Sciences

– Aeronautical Science “Interactions”

• Aero-structural interaction for membrane wings (MAVS)

• Shock-BL

• AFRL Transformational Opportunities:

– Realization of the MAV vision

• 2015 Bird-sized MAV

• 2030 Insect-sized MAV

– Sustained hypersonic flight ops

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Principal Collaborators

BALLSTON

AFOSR (RS):

- Schmisseur

- Smith

- Stargel

- Fahroo

- (Tishkoff)

- Nachman

- LuginslandEGLIN

MUNITIONS (RW):

- Zipfel

- Wehling

- Evers

- Abate

EDWARDSROCKET PROPULSION (RZ)- Cambier

WRIGHT-PATTERSON

AIR VEHICLES (RB):

- Poggie

- Visbal

- Ol

- Schumacher

- Johnson

- Beran

- Dale

- Kolonay

- Suchomel

- Tinapple

PROPULSION (RZ):

- Schauer & Zilena

- Carter

- Gord

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EOARD Aeronautical SciencesTechnical Directions

FY10

FY11

My Goal

*

* Area of excellence in

EU†Looking for

opportunities in EU

**

*

*

†Removing MAVs as a

“research” area

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A

C

Pl

S

M

P

F

Ma A

Ma

Pl

A

A

Ma

A

F

Israel

Ma

Pl

S

P

A A

Ma

Aerodynamics

Combustion

Plasma & MHD

Structures

MAV/UAV

Propulsion

Flight Controls

Mathematics

C

Research Locations

Pl

Pl

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Technical Highlights

• Selected topics for this presentation:

– Very low/slow

– Very high/fast

– Advancements of Conventional Vehicle

Technologies

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Research efforts to enable Very low/slow flight

Flapping wing

aerodynamics

Low Reynolds

number

fluid dynamics

Aero-Structure

Interaction Perching

Advanced flight

control

Multidisciplinary

Optimization

Unsteady

aerodynamics

Bio-Inspiration

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Perching of MAVs

Test section: 600x400 mm2

Velocity range: 2.5 - 20 m/s

Tu < 0.1% @ 10m/s

Core flow uniformity: 99%

LNB wind tunnel

Dynamic model support Linear direct drives with 12bit cam

resolution

Real time closed loop control

Max. plunging: 150mm @ 3Hz

Max. pitching: 20° @ 3Hz

Repetitive accuracy 0.05mm, 0.1°

“Perching Experiments at low Re”R. Radespiel, TU-Braunschweig

(Supported by RB)

Objective Identify and characterize unsteady flow phenomena

on flat plate wings during perching motion by force

measurement and PIV.

Key Results Force and PIV data gathered for varity of perch

maneuvers

Complex motion controller developed for WT tests

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Force measurements for the case AR=inf, Re=50000, k=0.03, PIV-plane at 1/3 span

Perching of MAVs

Flow evolution by selected time stages via PIV, averaged velocities, upright 1/3 span plane

stage stage stage stage stage

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Research efforts to enable Very high/fast flight

Shock-

interactions

BL Transition

Propulsion High order CFD

Advanced flight

control

Multidisciplinary

Optimization

Ablation

Aerodynamic

heating

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Energy deposition in high speed flows

“Experimental Studies on Effects of Thermal Bumps in the Flow-Field around a Flat Plate using a Hypersonic Wind Tunnel”

K. Kontis, Univ. of Manchester, UK(Supported by RB)

Objectives

• Understanding the basic gas-dynamic implications

of having a thermal bump (both surface heating and

volumetric heating) in a hypersonic flow

• Obtain instantaneous and time resolved

visualization of the flow field with and without

thermal bumps in hypersonic flow

• Measurement of surface static pressures with and

without the presence of thermal bumps at

hypersonic Mach numbers

Hypersonic Wind Tunnel facility

Approach:

• Hypersonic wind tunnel tests using the University

of Manchester hypersonic facility with a Mach 5

nozzle (unit Reynolds no. 6.2 to 11.4 x 10-6 /m)

• Schlieren, Shadowgraph and oil flow

visualisation, pressure measurements (Pressure-

Sensitive Paints, transducers), heat transfer

measurements (Infrared thermography)

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Key Results Weak oblique shock wave was

induced by the thermal bump

and perturbed thicker boundary

layer in the trailing edge of the

flat plate. Its strength is linked to

the power input;

Surface oil flow captured the

vortex structure as it develops

from upstream to downstream;

Variation in pitot pressure

distribution was more

pronounced 2mm above the

surface;

3-D effects were also captured

by pressure transducers and

infrared thermography (IR);

Stanton no. was increased

downstream of the heating

element;

Energy deposition in high speed flows

Temperature Map: heating off and on

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Research efforts on Advanced Conventional Technologies

Adv Propulsion

Technology

Shock-BL

InteractionMultidisciplinary

Optimization

High order CFD Advanced flight

control

Morphing

Aero-Structural

interaction

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“Shock Boundary Layer Interaction Flow Control with Micro Vortex Generators”

H. Babinsky, U. Cambridge(Supported by RB)

Shock-BL Interaction & Control

Objective• To determine the feasibility of Vortex

Generators (VGs) as an alternative to

boundary-layer bleed in inlet applications

• Main research interests:

• The simulation of typical inlet conditions

using a small-scale wind tunnel

• The evaluation of fundamental VG fluid

mechanics

Inlet Simulation: Novel setup developed to better simulate

fundamental flow physics of shock-wave / boundary-layer

interactions (SWBLI) in inlets

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Shock-BL Interaction & Control

Fundamental Inlet Study Fundamental VG Study• Addition of diffuser downstream of the normal shock results in

complex 3D flow

• VGs can suppress centre-line separation but enhance 3D and

corner effects

• Supersonic and subsonic behavior similar

• VG shape affects vortex positioning and

development. Optimum shape unknown

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New Research Initiative

• MAV 2030 goal

– Develop an “insect sized” micro air vehicle capable

of performing ISR and effects delivery missions

– International Initiative to highlight the challenge of

the MAV 2030 goal

– Invest in research to help meet this goal

• Bio-inspired control technologies for MAVs

• Embedded sensors & Actuators

• Develop BAA to highlight research needs for MAV 2030

– Coordinate amongst key AFRL/AFOSR/XOARD

personnel

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Upcoming Conf. Support

• 10th International Workshop on Magneto-Plasma

Aerodynamics, 22-24 March, Moscow, RU

• Fundamentals of aerodynamic-flow and combustion

control by plasma II, 27 Mar – 1 April, Houches, FR

• 4th European Conference for Aerospace Sciences, 4-8

July 2011, St Petersburg, RU

• 28th International Symposium on Shock Waves, 18-22

July, Manchester, UK

• IMAV 2011, 12-15 Sep 2011, Netherlands

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Summary

• Aeronautical Sciences at EOARD is a broad topic

area

• Seeking the best research interactions in the EOARD

Area of Responsibility

• Support and execute research collaborations with

AFOSR and AFRL TDs

• Primary focus on technologies for:

– Very low/slow

– Very high/fast

– Advancements of Conventional Vehicle Technologies

• New research initiative to address the MAV 2030 Goal

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Back-up Charts

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“Unsteady lift generation for micro air vehicles”H. Babinsky and A. Jones, U. Cambridge

(Supported by RSA, RB, & RW)

Unsteady Lift Generation at Low Re

Objectives

• What is the mechanism for unsteady lift production at low Re?

• Is spanwise flow a factor?

Key Findings

• What is the mechanism for unsteady lift production at low Re?

• Is spanwise flow a factor?

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Control & FSI for MAVs

“Control of Low Reynolds Number Flows with Fluid-Structure Interactions ”

I. Gursal, Univ. of Bath, UK(Supported by RSA)

Objectives exploit fluid-structure interactions to delay stall and

increase lift of airfoils and wings at low Reynolds

numbers

improve maneuverability and gust response of MAVs

simulate aerolastic vibrations by means of small-

amplitude plunging oscillations of airfoils and wings

develop flexible wings based on this knowledge.

Mode 2: vortex loses its

coherency through

impingement with the

upward moving airfoil; better

for thrust generation

Mode 1: leading-edge

vortex sheds and convected;

better for high-lift generation

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Hypersonic BL Transition

“Hypersonic Transition Experiments in 3DCone Flow with New Measurement

Techniques”R. Radespiel, TU - Braunschweig

(Supported by RSA)

Objectives• identify transition mechanisms of cones at angle of

attack

• improve advanced measurement techniques for BL

instabilities

• characterize instabilities in 3D flows

TU-B Mach 6 Ludwieg Tube

Key Findings Critical experimental data captured for Mach 6 flow

IR and pressure data captured for slender cone at

angles of attack with artificial roughness

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Advanced physical models of high enthalpy flows

“Advanced physical models and numerical methods for high enthalpy and plasma flows

applied to hypersonics”T. Magin, Von Karman Institute

(Supported by AFOSR & RZ)

Objectives• Development and validation of MUTATION:

MUlticomponent Transport And Thermodynamic

properties / chemistry for IONized gases

• Multilanguage support for greater flexibility

• Newly developed architecture facilitates

integration with existing solvers

• Facilitates extension to electronic CR—

collaboration with AFRL (Cambier)• Online support for latest

documentation/libraries

• GUI applet will allow

collaborators to remotely

compute thermophysical

properties via WWW

Java/JNIC/C++Fortran

Mutation F77

mutationlib.so

Application

Interface

Implementation

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“Development of a Class of Smoothness-Increasing Accuracy-Conserving (SIAC) Methods for Post-Processing

Discontinuous Galerkin Solutions”J. Ryan, TU-Delft, NL

(Supported by RSL)

Improved Modeling

Objectives

• To define, investigate, and address the technical obstacles

inherent in visualization of data derived from high-order

discontinuous Galerkin methods.

• To provide robust and easy to use algorithms to overcome

the difficulties that arise due to lack of smoothness.

Key Findings

•Most Significant Accomplishment: Numerically demonstrated

viability of applying this filter to discontinuous Galerkin

simulations on smoothly varying triangular mesh structures.

•Other Significant Accomplishments: Extended the filtering

technique to allow for non-periodic boundary data as well as

filtering in the neighborhood of discontinuities.

Benefit to Air Force: Improved visualization

algorithms for higher order methods

Smoothly varying

Triangular mesh:

Errors in the

Discontinuous

Galerkin solution:

O(h3)

Errors in the

Filtered solution:

O(h5)

Improved Streamline Calculation

even near boundaries.

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Key Points

•Assessing the effectiveness of increasing damping and/or shifting

frequency in flutter suppression

•Demonstrating the capability of the process when applied to systems

with flutter modes having close or separated frequencies

•The frequency range (limited by the data acquisition equipment),

possible spillover at high frequency and the treatment of spillover effects

•Assessing the effect of different measurement positions and numbers of

sensors

•Determining the displacements and rates necessary to achieve the

desired suppression and how these values change as the suppressed

closed-loop flutter speed increases

•Assessing the effects of noise (measurement noise and turbulence) on

the robustness of the process

Extension of Flutter Boundaries

“Extension of Flutter Boundaries Using In-Flight Receptance Data”

J. Mottershead, Univ. of Liverpool, UK(Supported by RB)

• Receptance Method depends upon

measured receptances from test data

• No modeling of structure or

aerodynamics required

Objectives

• Assessment in use of the Receptance Method for

application to aeroelastic systems

- Extension of flutter boundaries

• Design and manufacture of wing tunnel model for

experimental demonstration of the method