Simulation of Aircraft Encounters with Perturbed Vortices Considering Unsteady Aerodynamic Effects

Transcription

1 Simulation of Aircraft Encounters with Perturbed Vortices Considering Unsteady Aerodynamic Effects Berlin Institute of Technology Institute of Aeronautics and Astronautics, Flight Mechanics, Flight Control and Aeroelasticity D. Bieniek, R. Luckner WakeNet-Europe 2013 Workshop Bonneuil-sur-Marne, May 15, 2013

2 Who we are / What we do? Head of Department: Prof. Dr.-Ing. R. Luckner Nearly 15 years of wake vortex related research - Wake encounter modeling and simulation (real and fast-time applications) - Piloted flight simulator tests - Pilot modeling - Formation flight (modeling, simulation and control system development) Projects: S-WAKE, CREDOS, WakeNet-Europe, Research flight simulator SEPHIR Lufthansa A340 Full-Flight Simulator SEPHIR Slide 2

3 Motivation Potential hazard for encountering aircraft ICAO separations limit airport capacity Source: DLR Source: Rossow, 1996 Slide 3

4 Motivation Well defined encounter scenarios Safe test environment Real-time simulations: - Analysis of pilot response and severity assessment - Data for model development (pilot models, severity criteria) Fast-time simulations: - Parameter studies - Hazard and risk assessment Objective: Enhance realism of existing wake vortex encounter simulations Slide 4

5 Overview Wake Encounter Simulation Modeling of Wake Vortex Deformation Modeling of Unsteady Aerodynamic Effects Piloted Simulator Study Slide 5

6 Wake Encounter Simulation Vortex Trajectory and Vortex Data Geometric and Aerodynamic Data of the Aircraft WVE Software WVVM Configuration, Attitude and Trajectory of the Aircraft AIM Engine Module Aerodynamic Module [AERO] Pilot Inputs Basic Flight Simulation Kinematic Equations WVVM Wake Vortex Velocity Model AIM Aerodynamic Interaction Model Induced Forces And Moments Inverse Aerodynamic Module [AERO] -1 Sum of Forces and Moments Equivalent Linear Wind Field Integration Structure of WVE Software package developed during EC funded S-WAKE project Slide 6

7 Wake Encounter Simulation Encounter Scenario during Landing Approach Straight vortex axes V V V V 2D velocity field Source: Luckner, et al., 2004 Slide 7

8 Wake Vortex Deformation Straight Vortices Vortex Age Growing Crow Instability Beginning of Crow Instability Vortex Age Photos by Lauterbach, November 2011 Slide 8

9 Wake Vortex Deformation Wavy Vortices Vortex Age Mathematical modeling of phenomenon by S.C. Crow (1970) Crow Instability Vortex Linking and Formation of Vortex Rings Vortex Age Photos by Lauterbach, November 2011 Slide 9

10 Wake Vortex Deformation Models by Loucel / Crouch / Miller x V [b V ] V x V [b V ] b V r V y V [b V ] r V y V [b V ] z V [b V ] z V [b V ] r V x 0.5bV 1 A 0.5bV AV cos V V cos xv V x tan V V V r V nv b 1 sin c1 V a1 coss s b2 sin3 s cos2 s c 2 a 1 c 2 : shape parameters Slide 10

11 Wake Vortex Deformation Slide 11

12 Wake Vortex Deformation Discretization Biot-Savart Law Numerical integration of Biot-Savart law dv dl r 4 3 r Real-time and fast-time capable models not true to scale Slide 12

13 Wake Encounter Simulation Vortex Trajectory and Vortex Data Geometric and Aerodynamic Data of the Aircraft WVE Software WVVM Configuration, Attitude and Trajectory of the Aircraft AIM Engine Module Aerodynamic Module [AERO] Pilot Inputs Basic Flight Simulation Kinematic Equations WVVM Wake Vortex Velocity Model AIM Aerodynamic Interaction Model Induced Forces And Moments Inverse Aerodynamic Module [AERO] -1 Sum of Forces and Moments Equivalent Linear Wind Field Integration Structure of WVE Software package developed during EC funded S-WAKE project Slide 13

14 Wake Encounter Simulation Quasi-steady computation of forces and moments L V,i w V,i,qs Strip i V V,i L V,i = f( V,i, c L,i, max/min,i ) Slide 14

15 Unsteady Aerodynamic Effects Quasi-steady induced wind at strip i w V,i,qs F i (s) w V,i,us Unsteady induced wind at strip i Time-domain approximation of Küssner s Function Filter transfer function 0.13 ( ) e 0. 5 e F( s) 0.5 ( T ( T s 1) ( T 1 1 T 2 ) s 1 2 s 1) T 1 c V T 2 c 2 V 2 V c t Slide 15

16 Unsteady Aerodynamic Effects Frequency Response of Unsteady Lift Sample time of simulation: 0.02s VFW614-ATD (Landing approach) k 1.0 c 3. 30m V 56.8m / s 5.4Hz Slide 16

17 Unsteady Aerodynamic Effects x V -3% V = 5 V y V -10% V = 15 x V -20% V = 25 V,eff y V Results from static simulation (straight vortices, undisturbed straight flight path, no a/c dynamics) Slide 17

18 SEPHIR Research Simulator Simulated Aircraft: VFW614-ATD: Electronic FCS (Airbus like control laws) Wing span: 21.5 m, MTOW: 20 tons Simulator: 6DoF flight simulation High-fidelity visual system No motion system Slide 18

19 SEPHIR Research Simulator Screenshot of Wavy Vortices V y V z V x V Movie of Wake Vortex Encounter Slide 19

20 Piloted Simulator Study Objective: Investigate effects of vortex deformation on wake encounter 11 sessions with airline pilots (454 encounters) Manual ILS approach (VMC) Scenarios Six deformation levels Encounter angles: V = 0-20 and V = -3, -5, -10 Fixed vortex parameters Encounters at ft above ground Slide 20

21 Piloted Simulator Study Type A Type C Type B Upwind Upwind Downwash Slide 21

22 Piloted Simulator Study Slide 22

23 Results Top View ( V = 10 ) Straight Vortices = 383 m 2 /s Vortex Rings = 362 m 2 /s Wavy Vortices = 383 m 2 /s Slide 23

24 Results Core Radius Cases with no lateral encounter angle V = 0 and mostly small vertical encounter angles V = -3 /-5 Core Radius Cases with no lateral encounter angle V = 0 and mostly small vertical encounter angles V = -3 /-5 Core Radius Pilot Overall Hazard Rating (OHR) Increasing Hazard Results from encounter types A and B only Slide 24

25 Results Comparable average ratings for straight and wavy vortices Larger spread of ratings for wavy vortices Highest rating only used for wavy vortex encounters Mostly low hazard ratings for vortex ring encounters Overall rating distribution skewed Slide 25

26 Results NOGA Approach continued GA Go-around maneuver Slide 26

27 Conclusions Consideration of wake vortex deformation and unsteady aerodynamic effects enhances realism of existing encounter simulations Wake deformation affects aircraft upsets First impressions: - Wider range of upsets for wavy vortices - Vortex rings appear less hazardous Evaluation of complete range of encounter scenarios required Slide 27

28 Outlook Preparation of fast-time simulations Integration of LES vortex wind fields into encounter simulations provided by UCL Analytical simulation models vs. LES data based simulations LES wind field in SEPHIR simulator Slide 28

29 Questions / Comments This work was funded by the German Research Foundation under contract LU 1397/1-1. Thank You for Your Attention! Dipl.-Ing. David Bieniek Phone: david.bieniek@ilr.tu-berlin.de Slide 29

30 This document and all information contained herein is the sole property of TU Berlin. No intellectual property rights are granted by the delivery of this document or the disclosure of its content. This document shall not be reproduced or disclosed to a third party without the express written consent of TU Berlin. This document and its content shall not be used for any purpose other than that for which it is supplied. The statements made herein do not constitute an offer. They are based on the mentioned assumptions and are expressed in good faith. Where the supporting grounds for these statements are not shown, TU Berlin will be pleased to explain the basis thereof. Slide 30