Document
www.nasa.gov June 9, 2009 Airframe Icing Workshop NASA Glenn Research Center
NASA Perspective
Airframe Icing Research Gaps
Cleveland, Ohio National Aeronautics and Space Administration NASA/CP—2009-215797 87 www.nasa.gov p
Current Airframe Icing Technology Gaps (1/2)
Development of scaling methods for SLD conditions Development of a full 3D ice accretion simulation model Development of an improved simulation model for SLD conditions CFD modeling of stall behavior for ice-contaminated wings/tails Computational methods for simulation of stability and control parameters Analysis of thermal ice protection system performance Quantification of 3D ice shape geometric characteristics Development of accurate ground-based simulation of SLD conditions Development of advanced diagnostic techniques for assessment of tunnel cloud conditions Identification of critical ice shapes for aerodynamic performance degradation Aerodynamic scaling issues associated with testing scale model ice shape geometries Development of altitude scaling methods for thermal ice protections systems • • • • • Computational Methods • • • • • • • Experimental Methods National Aeronautics and Space Administration NASA/CP—2009-215797 88 www.nasa.gov p
Current Airframe Icing Technology Gaps (2/2)
Development of accurate parameter identification methods Measurement of stability and control parameters for an ice-contaminated swept wing aircraft Creation of control law modifications to prevent loss of control during icing encounters 3D ice shape geometries Collection efficiency data for ice shape geometries SLD ice shape data, in-flight and ground-based, for simulation verification Aerodynamic performance data for 3D geometries and various icing conditions Stability and control parameter data for iced aircraft configurations Thermal ice protection system data for simulation validation • • • Flight Dynamics • • • • • • Experimental Databases National Aeronautics and Space Administration NASA/CP—2009-215797 89 www.nasa.gov
Airframe Icing Research
nistration
Aviation Community Areas of Interest
Ground based facilities Computational methods SLD Icing physics SLD scaling methods Modify ground based facilities Modify computational methods Ground based facilities Computational methods Flight Simulation – – – – – – – – –
Ice Accretion Simulation Iced Aircraft Performance Evaluation
Fixed Wing Airframe Icing • • Development of SLD ‘Means of Compliance’ •
National Aeronautics and Space Administration NASA/CP—2009-215797 90 www.nasa.gov : Full scale Ice growth on subscale
Fixed Wing Airframe Icing
Methods are needed to simulate, experimentally and computationally, the Our ability to model ice growth on swept wings, future generation aircraft Current NASA effort: swept wings is being investigated in understanding intelligent controls response to an icing encounter. Potential NASA Role to Fill Gaps swept wing and SLD ice accretion simulation research.
Ice Accretion Simulation Issue: process of ice growth on aircraft surfaces to reduce flight test cost and to improve safety. These methods are used for design, analysis, and certification efforts performed by industry and government. Gaps: configurations (e.g. blended wing body), and for Supercooled Large Droplet (SLD) (i.e. freezing drizzle and rain) conditions are limited and lack a comprehensive database for validation. Ice accretion physics, such as, water film dynamics on ice substrates and heat transfer augmentation on complex rough ice surfaces are not well understood and require further research. Also, ice accretion scaling methods need to be extended and validated for large scale configurations envisioned for next-generation aircraft.
National Aeronautics and Space Administration NASA/CP—2009-215797 91 www.nasa.gov p
Current Airframe Icing Technology Gaps (1/2)
Development of scaling methods for SLD conditions Development of a full 3D ice accretion simulation model Development of an improved simulation model for SLD conditions CFD modeling of stall behavior for ice-contaminated wings/tails Computational methods for simulation of stability and control parameters Analysis of thermal ice protection system performance Quantification of 3D ice shape geometric characteristics Development of accurate ground-based simulation of SLD conditions Development of advanced diagnostic techniques for assessment of tunnel cloud conditions Identification of critical ice shapes for aerodynamic performance degradation Aerodynamic scaling issues associated with testing scale model ice shape geometries Development of altitude scaling methods for thermal ice protections systems • • • • • Computational Methods • • • • • • • Experimental Methods National Aeronautics and Space Administration NASA/CP—2009-215797 92 www.nasa.gov p
Current Airframe Icing Technology Gaps (2/2)
Development of accurate parameter identification methods Measurement of stability and control parameters for an ice-contaminated swept wing aircraft Creation of control law modifications to prevent loss of control during icing encounters 3D ice shape geometries Collection efficiency data for ice shape geometries SLD ice shape data, in-flight and ground-based, for simulation verification Aerodynamic performance data for 3D geometries and various icing conditions Stability and control parameter data for iced aircraft configurations Thermal ice protection system data for simulation validation • • • Flight Dynamics • • • • • • Experimental Databases National Aeronautics and Space Administration NASA/CP—2009-215797 93 www.nasa.gov Expansion of limited IRT SLD Testing at a limited set of SLD conditions is
Fixed Wing Airframe Icing
ministration Note: These gaps are in addition to those in “ice accretion Modifications to the Icing Research Tunnel (IRT) and associated Methods are needed to simulate, experimentally and computationally, the Development of SLD ‘Means of Compliance’ Issue: process of Super-cooled Large Droplet (SLD) ice growth on aircraft surfaces to reduce flight test cost and to improve safety. These methods are needed for industry to have a ‘means of compliance’ with proposed regulations for flight in SLD conditions. Gaps: instrumentations are needed to simulate SLD environments. Deficiencies in knowledge of droplet dynamics (i.e. droplet breakup, impingement, and splashing) and feather formation for SLD conditions still exist. Computational modeling is largely based upon empirical information and correlations. Current means of compliance does not cover the full range of SLD conditions. Scaling methods are not adequately validated for SLD environments. simulation.” Current NASA Effort: currently performed as part of the existing icing physics programs. Potential NASA Role to Fill Gaps: capabilities; improve and validate scaling methods for SLD; more comprehensive SLD physics studies performed at icing physics flow lab; improve and validate ice accretion models National Aeronautics and Space Administration NASA/CP—2009-215797 94 www.nasa.gov p
Current Airframe Icing Technology Gaps (1/2)
Development of scaling methods for SLD conditions Development of a full 3D ice accretion simulation model Development of an improved simulation model for SLD conditions CFD modeling of stall behavior for ice-contaminated wings/tails Computational methods for simulation of stability and control parameters Analysis of thermal ice protection system performance Quantification of 3D ice shape geometric characteristics Development of accurate ground-based simulation of SLD conditions Development of advanced diagnostic techniques for assessment of tunnel cloud conditions Identification of critical ice shapes for aerodynamic performance degradation Aerodynamic scaling issues associated with testing scale model ice shape geometries Development of altitude scaling methods for thermal ice protections systems • • • • • Computational Methods • • • • • • • Experimental Methods National Aeronautics and Space Administration NASA/CP—2009-215797 95 www.nasa.gov p
Current Airframe Icing Technology Gaps (2/2)
Development of accurate parameter identification methods Measurement of stability and control parameters for an ice-contaminated swept wing aircraft Creation of control law modifications to prevent loss of control during icing encounters 3D ice shape geometries Collection efficiency data for ice shape geometries SLD ice shape data, in-flight and ground-based, for simulation verification Aerodynamic performance data for 3D geometries and various icing conditions Stability and control parameter data for iced aircraft configurations Thermal ice protection system data for simulation validation • • • Flight Dynamics • • • • • • Experimental Databases National Aeronautics and Space Administration NASA/CP—2009-215797 96 www.nasa.gov Full scale, high Re number iced a o Use Generic Transport Model (GTM) for
Fixed Wing Airframe Icing
s Methods are needed to simulate, experimentally and computationally, the Limited capability with either experimental or computational Iced Aircraft Performance Evaluation Issue: degradation in performance of an aircraft exposed to in-flight icing conditions. These methods are used for design, analysis, and certification efforts performed by industry and government. Information from this research is used to provide input to controls-based remediation efforts.
Gaps: methods to determine performance changes (lift, drag, stability and control) for iced aircraft. This is related to limited understanding of Reynolds number and ice accretion geometry scaling for swept wing and full aircraft configuration. Applications of computational methods (e.g. turbulence, roughness, grid generation) to iced surface has not been adequately validated. Current NASA Effort: examination of controls response to ice build-up. Note: Experimental effort is subscale and computational effort is both full- and subscale. Development of a CFD approach to calculate influence of ice build-up on aircraft aerodynamics and resulting control system behavior. Potential NASA Role to Fill Gaps: modern aircraft (e.g. swept wing) aerodynamic research and validation database development National Aeronautics and Space Administration NASA/CP—2009-215797 97 www.nasa.gov p
Current Airframe Icing Technology Gaps (1/2)
Development of scaling methods for SLD conditions Development of a full 3D ice accretion simulation model Development of an improved simulation model for SLD conditions CFD modeling of stall behavior for ice-contaminated wings/tails Computational methods for simulation of stability and control parameters Analysis of thermal ice protection system performance Quantification of 3D ice shape geometric characteristics Development of accurate ground-based simulation of SLD conditions Development of advanced diagnostic techniques for assessment of tunnel cloud conditions Identification of critical ice shapes for aerodynamic performance degradation Aerodynamic scaling issues associated with testing scale model ice shape geometries Development of altitude scaling methods for thermal ice protections systems • • • • • Computational Methods • • • • • • • Experimental Methods National Aeronautics and Space Administration NASA/CP—2009-215797 98 www.nasa.gov p
Current Airframe Icing Technology Gaps (2/2)
Development of accurate parameter identification methods Measurement of stability and control parameters for an ice-contaminated swept wing aircraft Creation of control law modifications to prevent loss of control during icing encounters 3D ice shape geometries Collection efficiency data for ice shape geometries SLD ice shape data, in-flight and ground-based, for simulation verification Aerodynamic performance data for 3D geometries and various icing conditions Stability and control parameter data for iced aircraft configurations Thermal ice protection system data for simulation validation • • • Flight Dynamics • • • • • • Experimental Databases National Aeronautics and Space Administration NASA/CP—2009-215797 99 www.nasa.gov
Discussion of Airframe Icing Technology Gaps
It is our desire to compare the technology gaps identified in this presentation with those deemed of importance to industry and other government organizations and come to some consensus on what research areas should be pursued if appropriate resources become available.
National Aeronautics and Space Administration NASA/CP—2009-215797 100