(Brieuc.Danet@onera.fr) 4th European Micro-UAV Meeting REMANTA REsearch program on Micro Aerial vehicle and New Technologies Application Brieuc DANET (Brieuc.Danet@onera.fr) 4th European Micro-UAV Meeting Toulouse, 15th September 2004

Objectives of the Research Program Topic 1 : Experimental Aerodynamics Topic 2 : Flight Mechanics and Control Topic 3 : Materials, Structures, Actuators Continuation of the Project

Objective: Feasability and interest of a flapping-wing MAV 1. Objectives Objective: Feasability and interest of a flapping-wing MAV Caracteristics of the vehicle: Small size : wing span < 15 cm Mass ~ 100 g Ability of stationary flight Large autonomy

Biomimetism Understand the phenomena that permit animals to fly 1. Objectives Biomimetism Understand the phenomena that permit animals to fly Find accurate technical solutions Copying nature is not the right way (multipurpose aspect of parts of the body)

Large interactions between the domains 1. Objectives Scientific and technological challenge: Low Reynolds aerodynamics  Numerous complex unsteady phenomena (dynamic stall, wake capture) Control and command of wing kinematics in cruise, stationary  Unusual flight dynamics flights and manoeuvers Huge influence of mass  Light materials Flexible structures  Aeroelasticity High frequency sollicitations  Accurate actuators Large interactions between the domains

Topic # 1: Experimental Aerodynamics

- qualitative: observe and describe to understand phenomena 2. Topic #1: Experimental Aerodynamics 2 objectives: - qualitative: observe and describe to understand phenomena  Visualizations of aerodynamic flows - quantitative: correlate wing kinematics with sustentation and propulsion to feed models with empiric data  Measurements of aerodynamic forces and torques

Experiments in the air: - Uneasy visualizations 2. Topic #1: Experimental Aerodynamics Experiments in the air: - Uneasy visualizations - Inertial forces >> Aerodynamic forces i.e. difficult analysis of measures Experiments in water with conservation of : Reynolds number ( ) and reduced frequency ( )

Facilities Lille: Water Tank - Section H1.5m x W1.5m x L25m 2. Topic #1: Experimental Aerodynamics Facilities Lille: Water Tank - Section H1.5m x W1.5m x L25m - V (moving platform) = 0.1 to 1 m/s - Injection of dyed liquid.

Facilities Toulouse: Water Tunnel - max Flow rate 20 l/s (slaved) 2. Topic #1: Experimental Aerodynamics Facilities Toulouse: Water Tunnel - max Flow rate 20 l/s (slaved) - Section up to H500xP600 (V=13 cm/s) - Slaved and controlled dyed liquid injection (flow rate and position)

Testing conditions NACA 0012 Profile (not optimal but well documented) 2. Topic #1: Experimental Aerodynamics Testing conditions Re ~ 104 - 105 NACA 0012 Profile (not optimal but well documented) Realization of a coupled mechanism 2D : plunging and pitching 3D : flapping and pitching Application: cruise flight Measurements: - 5 components balance (no axial component) for measurement of forces and torques and evaluations of Cx, Cz,… - Image acquisition. Laser Tomography

2. Topic #1: Experimental Aerodynamics 2D Mechanism

2. Topic #1: Experimental Aerodynamics 3D Mechanism

2. Topic #1: Experimental Aerodynamics Mechanism installed on the wall Coupled Mechanism

2. Topic #1: Experimental Aerodynamics 2 testing campaigns (2003 & 2004): More than 800 tests (3D and quasi-2D)

2. Topic #1: Experimental Aerodynamics Results

Visualizations f = 0.5 Hz ; U = 0 m/s f = 0.5 Hz ; U = 0.25 m/s 2. Topic #1: Experimental Aerodynamics Visualizations f = 0.5 Hz ; U = 0 m/s f = 0.5 Hz ; U = 0.25 m/s

Topic # 2: Flight Mechanics and Control

Unusual Flight Mechanics 3. Topic #2: Flight Mechanics and Control Unusual Flight Mechanics Model based on the flight analysis of insects and birds Cruise and hovering flights Linear model + unsteady effects (Dynamic delayed stall, etc) Use of aerodynamic data issued from experiments (open literature and ONERA )

Topic # 3: Materials, Structures, Actuators

 Concepts inspired by nature 4. Topic #3: Materials, Structures, Actuators - Selection, elaboration and characterization of light materials (composites carbon/epoxy) - Modelization of structures under high frequency requests with aero coupling - Search of actuators adapted to kinematics  Concepts inspired by nature

Light Materials 4. Topic #3: Materials, Structures, Actuators Terphane 29 m Composite T300/914 Total Mass: 0,6 g 60 mm frequency : 30 Hz distance between supports : 10 mm deformation : +/- 0,1 or 0,2 or 0,4 mm Flexion tests :

Structures Assumptions: ROTOR code (D. Petot) 3D mechanism 4. Topic #3: Materials, Structures, Actuators Structures Calage Wing Assumptions: ROTOR code (D. Petot) 3D mechanism Rotation simulates forward flight Decoupled joints Classical aerodynamic Rigid Wing Low Mass fondamental beat frequency : 8 Hz Pitching articulation Rotation axis Flapping articulation

Actuators Dynamical model “at resonance” non-linear model 4. Topic #3: Materials, Structures, Actuators Actuators Dynamical model “at resonance” non-linear model behavior of actuators - active behavior - elastic and inertial behavior

Continuation of the Project (work for 2005) Numerical aerodynamics : Different approaches are now in progress : NS, LES - NS 2D Adaptative grid Re = 1000 U = 1m/s c = 2 cm Stc = 0.4 (f = 20 Hz) Stc = 0.8 (f = 40 Hz)

Continuation of the Project (work for 2005) Experimental aerodynamics: - A second mechanism to widen the range of kinematic parameters (hovering flight) - Visualization of the flows Implementation of flight mechanics and aeroelasticity with unsteady models

Contacts: Management: Agnès Luc-Bouhali (Agnes.Luc-Bouhali@onera.fr) Flight Mechanics and Control: Laurent Planckaert (Laurent.Planckaert@onera.fr) Aerodynamics: Jean-Bernard Paquet (Jean-Bernard.Paquet@onera.fr) Materials, Structures, Actuators: Daniel Osmont (Daniel.Osmont@onera.fr)