Scientific Aspects of Weather Hazards for Aviation · 2015. 7. 3. · 10 100 1000 0 1 10 100 particle diameter ( m) DN particle number concentration within siz e bin (1/cm3), referring

Scientific Aspects of Weather Hazards for Aviation

Andreas PetzoldDLR, Institut für Physik der Atmosphäre

[email protected]

aerodays 2011 | madrid | 30 ‐ 31 march 2011

aerodays 2011 | madrid | 30 ‐ 31 march 2011 2

Atmospheric Hazards for Aviation

deep convection

volcanoes

dust storms

birds


http://www.radarvirtuel.com/ taken from BBC: Iceland volcano in maps

19 April 2010, 13:00 UTC - Mid-European Airspace Closed


ICAO Operator Risk Assessment Framework

Operator

establishes safety assessment process

uses all information including VAAC forecast

understands data and resolves conflicts

decides when and where to fly


1. Identify the hazards.a. Perform adequate research on the short and long term effects of volcanic ash

on the entire aircraft and their occupants.b. Conduct an in-depth risk analysis for the hazards of aircraft operation in VA.c. Establish generic engine ash tolerance levels based on actual data and

research for relevant ash parameters.

2. Identify the contaminated airspace.a. Improve modelling, measurement and/or sensing accuracy of ash particle size

and density in volcanic ash clouds.b. VAAC must deliver relevant data in an accurate, timely and robust way by

means of measurement, imaging, modelling and validation.c. The appropriate safety oversight authority shall establish a danger area.d. Uniform global criteria for closure of (parts of) airspace should be applied in

case of unacceptable hazardous ash concentrations (the no-fly black zone).


1. Identify the hazards.a. Perform adequate research on the short and long term effects of volcanic ash

on the entire aircraft and their occupants.b. Conduct an in-depth risk analysis for the hazards of aircraft operation in VA.c. Establish generic engine ash tolerance levels based on actual data and

research for relevant ash parameters.

2. Identify the contaminated airspace.a. Improve modelling, measurement and/or sensing accuracy of ash particle size

and density in volcanic ash clouds.b. VAAC must deliver relevant data in an accurate, timely and robust way by

means of measurement, imaging, modelling and validation.c. The appropriate safety oversight authority shall establish a danger area.d. Uniform global criteria for closure of (parts of) airspace should be applied in

case of unacceptable hazardous ash concentrations (the no-fly black zone).

RESEARCH NEEDED ON PARTICLE IMPACT ON AIRFRAME & ENGINE

RESEARCH NEEDS FOR THE DEVELOPMENT OF ON-BOARD INSTRUMENTATION


Glassy particles will melt in the combustion chamber, if high thrust rating is used.

Melted material will cool down in the turbine and deposit on the turbine vanes.

DLR Falcon flights

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_sd3_2010-04-19_150835-151535_f

_sd3_2010-05-02_151125-151435_f

Abrasive particles can erode compressor blades edges, reducing compressor performance.

Properties and Impacts of Hazardous Particles

volcanic ashmineral dust


Volcanic Ash and Mineral Dust Particle Impact on Engines

Modelling Particle Trajectories at Cruise Condition

Particle Concentration:•2 – 4 x 10-4 g/m3

•Up to 4 x 10-3 g/m3 • Track inert particles• Melting temperature ~1050°C• Monitor particle temperature history

• Determine concentration and combustor passage factor

• Determine molten particle factor (potential accumulation/stick on turbine blades)

• Determine particle profile

• Find reasonable wall modelling

Particle Properties:•Density 2 g/m3

DLR Falcon flights

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_sd3_2010-04-19_150835-151535_f

_sd3_2010-05-02_151125-151435_f

adapted from S. Bake, R-R


Phase diagram for quartz – leucite – cordierite

Thornton et al. 1960, Am. J. Sci. 258, 664-684

A combination of minerals with high melting points can result in significantly lower melting points of the mixture

Dependency of Melting Point Temperature on Composition

by courtesy of K. Kandler, TU DarmstadtThornton et al. 1960, Am. J. Sci. 258, 664-684


Research Needs - VA impact on aircraft

Wide range of particle size in volcanic plumes (>1mm to <1µm), but only particles <20mm (strong plumes) and <1mm (weak plumes) reach the horizontally spreading current.

Melting properties of mixed particles are hardly to predict because a combination of minerals with high melting points can result in significantly lower melting points of the mixture; melting may start at 900 °C.

Impact of high pressures inside the engine and high water content on melting behaviour of VA particles is not clear.

Models are required for assessing the impact of large particles on aircraft engines, including the conditions inside a gas turbine combustor.

Agglomeration of VA particles is a key process influencing particle lifetime and particle size distribution, generating large uncertainties in atmospheric modelling and VA mass concentration forecast.


Properties and Impacts of Hazardous Particles

ice crystals

Super cooled drops form ice on cold surfaces of inlet, fan, and front of compressor

Ice crystals form ice on warm surfaces inside

the compressor

Supercooled liquid water accretion area inlet, spinner, fan, and first stages of the core


Ice Crystals Impact on Engines

J.‐F. Gayet (Univ. Clermont‐Ferrand)


Research Needs - Ice Crystal/SLD Impact on Aircraft

Formation conditions of dense ice crystal clouds not well known.

Impact of supercooled large droplets on aircraft engines is not clear.

Forecast of formation conditions for supercooled large droplets is nor sufficiently solved.

Research Needs - Weather Hazards

Forecast hazardous areas.

Identify hazardous areas.

Develop on-board measurement techniques for warning and for detection purposes.

Quantify hazardous potential.


IAGOS - Instrumented Civil Aircraft for Routine Observation of Atmospheric Composition, Aerosols and Clouds

www.iagos.org

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WEZARD – WP5: Scientific Support WBS & Content

March 2011CSA-SA on Weather Hazards for Aeronautics - WP5: Scientific Support

Task 5.0Supervision

and Roadmap

Task 5.1Atmospheric conditions causing air transport system

disruptions

Task 5.2Instrumentation for measuring

hazardous particles

Task 5.3Use of UAS

Task 5.4Reproduction of

hazardous particles

environments

Task 5.5Modelling, Tools and

Simulations

Identify research needs based on the gap analyses performed in Tasks 5.1 to 5.5 and build an integrated research roadmap as input to WP1

Review of the current status of knowledge concerning particles and ice crystals

Review and gap analysis of concepts and instrumentation available for the measurement of hazardous aerosol particles, SLD, mixed phase and ice crystals

Review and gap analysis of the use of UAS and development of UAS instrumentation for in situ measurements in hazardous weather conditions

Review the test facilities available in Europe for the identified studies and develop a test schedule for the identified studies

Review and gap analysis of models available for studying the impact of hazardous particles and icing on airframes, engines and systems

Formulate conclusive recommendations and the common roadmap as input to the strategic reports

WP5 : Scientific Support


Thank youThank you

Documents

Scientific Aspects of Weather Hazards for Aviation · 2015. 7. 3. · 10 100 1000 0 1 10 100 particle diameter ( m) DN particle number concentration within siz e bin (1/cm3), referring