120 likes | 150 Views
DESIGN ISSUES RELATED TO A BWB. ICRAT 2004. Aitor Iñiguez de Heredia Dr. Holger Friehmelt Zilina, 22 nd -24 th November DLR Institute of Flight Systems. CONTENTS. Market Requirements. Air Transport Solutions. The BWB Contribution. A General BWB. BWB Advantages.
E N D
DESIGN ISSUES RELATED TO A BWB ICRAT 2004 Aitor Iñiguez de Heredia Dr. Holger Friehmelt Zilina, 22nd-24th November DLR Institute of Flight Systems
CONTENTS • Market Requirements • Air Transport Solutions • The BWB Contribution • A General BWB • BWB Advantages • BWB Challenges • Our Work at DLR • Conclusions DLR Institute of Flight Systems
4.7% Growth until 2020 Market Evolution can be modelled by Scenarios SOLUTION?! MARKET REQUIREMENTS Source: Airbus High Number of AC are Reaching Their End of Service Life Air Space & Airport Saturation Conventional AC Will Not Fulfil Environmental Requirements DLR Institute of Flight Systems
HOW? Solution for Air-Transport Problems Increasing Number of AC Increasing Cruise Speed of AC Increasing Aircraft Capability Reducing Turn-around Time & Take-off/Landing Separation AIR TRANSPORT SOLUTIONS (i) ? ? DEVELOPMENT PRIORITIES Capacity Environment Safety Cost Technology Described by Vision 2020 DLR Institute of Flight Systems
CAPABILITY INCREASING CRUISE SPEED INCREASING “MOST PROMISING SOLUTION” AIR TRANSPORT SOLUTIONS (ii) Unconventional Configurations Conventional Configurations “Faster and Higher” Is it achievable? Local Application (Caribbean Sea, Mediterranean…) Conventional Scaled Versions Long Range & High Density Structural & Design Reached Radical Capacity Increase Liebeck, Hepperle, Bowers… DLR Institute of Flight Systems
THE BWB CONTRIBUTION Today 1935 1949 1989 1929 Lippisch BWB Horten II YB-49 B2 If so Good: Why not Before a Civil BWB? Stability and Lateral Directional Problems Too Innovative ?? First Unstable Civil AC DLR Institute of Flight Systems
No High Lift Devices are Required Engines in Upper Fuselage Decrease Noise Problems Reduced Induced Drag Laterally Unstable Without VS or Wing Tips Large Reference Surface VS Recover LAT Stability and Directional Control Fuselage Produces Lift Large Usable Area No Stall Danger FULLY FBW AC A GENERAL BWB, WHAT IS A BWB? Option A Option C Option B Longitudinally Unstable Poorly Laterally Damped Requires SAS and CAS for LAT and LON Motions DLR Institute of Flight Systems
Improved Payload 104 ton Vs 84 ton BWB Vs A380-100 Increased Range 750 pax Vs 555 BWB Vs A380 Improved Capability No High Lift Devices Reduced Noise Landing/Take-off Flexibility (Green 24 Hours) Low Climb Speed Allowed AIRCRAFT ADVANTAGES DLR Institute of Flight Systems
Roll Rate Limiters Passengers on outward Fuselage Large Vertical Accelerations 1st Civil Unstable AC Review of FCS Requirements Large Elastic Motion Expected Large Accelerations and Velocities Due to Rotation …AND CHALLENGES nz Evacuation (750 Pax!) Comfort Problems… (No Windows) …or not (New Technologies) Structural Design (Non Cylindrical Fuselage) Airport Saturation/Infrastructure DLR Institute of Flight Systems
BWB MODEL STABILITY FCS DESIGN SIMULATION OUR WORK AT DLR • Wind Tunnel Data Base • MATLAB 6DoF Analytical Model • Flight Envelope (h, v, mass) • Instabilities ID • CAS&SAS Required • Engine Failure • CAS&SAS Designed • Robust Design • LQR Algorithms • Autopilots • HQ Review • Pilot in the Loop • In-Flight Simulation • Aeroelastic Coupling with FCS • Systems Integration hm H Dynamic Compensator 6DoF Augmented AC 6DoF Augmented AC y Gc -L Gc -L err h com Feedforward Gain Matrix y = AC Response hm = Measured Altitude K err = Error Signal Feedback Gain Matrix DLR Institute of Flight Systems
CONCLUSIONS Great Chances for Air Traffic/Enviroment Problem An Optional, Compatible Solution together with Other Procedures for Air-Traffic Problem: “It is a Partial Solution, not THE Solution” Reduced Noise Problems Expected Stability and Control Problems Already Solved for Lateral and Longitudinal Motions. Technology is Available But… Unsolved Questions: Structural Design, Evacuation Procedures, Comfort Problems will Suppose an Extra Issue, Airport Infrastructures Challenges: Elastic Modes/FCS Coupling, Handling Qualities for a Fully FBW Civil AC DLR Institute of Flight Systems
THANK YOU ! Further information: Aitor.Iniguez@dlr.de DLR Institute of Flight Systems