Operation of Gas Turbine Engines in an Environment Contaminated With Volcanic Ash

Dunn, Michael G.

doi:10.1115/1.4006236

Cited by 98 publications

(63 citation statements)

References 10 publications

(17 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The "zero ash tolerance" guideline was mainly justified by the limited knowledge about the tolerance of turbine engines to the ingestion of ash particles (Dunn and Wade 1994;Dunn 2012). However, for other types of particulate matter more commonly ingested (e.g., mineral sand) flight operations are permitted within a certain threshold of particle concentration.…”

Section: Introductionmentioning

confidence: 99%

“…The dramatic extent of the disruption stemmed from the "zero ash tolerance" guideline followed by decisionmakers at the time of the Eyjafjallajökull eruption. This guideline (Miller and Casadevall 2000;International Civil Aviation Organization [ICAO] 2007) had been implemented by the International Civil Aviation Organization [ICAO] after the 1982 Galunggung (Indonesia) and 1989 Redoubt (USA) incidents (Guffanti et al 2010;Dunn 2012), based on the Proceedings of the First International Symposium on Volcanic Ash, held in Seattle, Washington, in July 1991 (Casadevall 1994). This rule had been widely accepted by all legal authorities and airline companies, as well as airplane and turbine manufacturers.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

The thermal stability of Eyjafjallajökull ash versus turbine ingestion test sands

et al. 2014

View full text Add to dashboard Cite

The 2010 eruption of Eyjafjallajökull (Iceland) and the 2011 eruptions of Grimsvötn (Iceland), Cordon Caulle (Chile) and Nabro (Ethiopia) have drastically heightened the level of awareness in the general population of how volcanic activity can affect everyday life by disrupting air travel. The ingestion of airborne volcanic matter into jet turbines may cause harm by (1) abrasion of engine parts, (2) destabilisation of the fuel/air mix and its dynamics and (3) by melting and sintering ash onto engine parts. To investigate the behaviour of volcanic ash upon reheating, we have performed experiments at ten temperature steps between 700 and 1600°C on (1) fresh volcanic ash from the final explosive phase of the 2010 Eyjafjallajökull (EYJA) eruption and (2) two standard materials used in ingestion tests in the history of turbine testing (MIL E 5007C test sand, MIL; Arizona Test Dust, ATD). We confirm expected large differences in the samples' response to thermal treatment. We quantify the physical basis for these differences using thermogravimetry and differential scanning calorimetry. Glassy volcanic ash softens at temperatures that are considerably lower than those required for crystalline silicates to start to melt. We find that volcanic ash starts softening at temperatures as low as 600°C and that complete sintering takes place at temperatures as low as 1050°C. Accordingly, the ingestion of volcanic ash in the hot zone of turbines will rather efficiently transform the angular volcanic particles into sticky droplets with a high potential of adhering to surfaces. These experiments demonstrate both a large variability in the material properties of ash from Eyjafjallajökull volcano and a strong contrast to the behaviour of the test sands. In light of these differences, the application in volcanic crises of models of the impact of ash on operability of passenger jet turbines that have been based on test sand calibrations must be re-evaluated. We stress as well that ingestion tests should not only investigate the turbine's response to ash concentration (g/m 3 ) but also to ash dosage.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

The thermal stability of Eyjafjallajökull ash versus turbine ingestion test sands

et al. 2014

View full text Add to dashboard Cite

show abstract

“…To date studies on the impacts of volcanic hazards to society have focussed on the effects of ash [2][3][4][5][6][7][8][9][10][11][12][13]. These studies and reports suggest four frequently occurring types of volcanic ash impacts on surface transport:…”

Section: Introductionmentioning

confidence: 99%

Impact of Volcanic Ash on Road and Airfield Surface Skid Resistance

et al. 2017

View full text Add to dashboard Cite

Volcanic ash deposited on paved surfaces during volcanic eruptions often compromises skid resistance, which is a major component of safety. We adopt the British pendulum test method in laboratory conditions to investigate the skid resistance of road asphalt and airfield concrete surfaces covered by volcanic ash sourced from various locations in New Zealand. Controlled variations in ash characteristics include type, depth, wetness, particle size and soluble components. We use Stone Mastic Asphalt (SMA) for most road surface experiments but also test porous asphalt, line-painted road surfaces, and a roller screed concrete mix used for airfields. Due to their importance for skid resistance, SMA surface macrotexture and microtexture are analysed with semi-quantitative image analysis, microscopy and a standardised sand patch volumetric test, which enables determination of the relative effectiveness of different cleaning techniques. We find that SMA surfaces covered by thin deposits (~1 mm) of ash result in skid resistance values slightly lower than those observed on wet uncontaminated surfaces. At these depths, a higher relative soluble content for low-crystalline ash and a coarser particle size results in lower skid resistance. Skid resistance results for relatively thicker deposits (3-5 mm) of non-vesiculated basaltic ash are similar to those for thin deposits. There are similarities between road asphalt and airfield concrete, although there is little difference in skid resistance between bare airfield surfaces and airfield surfaces covered by 1 mm of ash. Based on our findings, we provide recommendations for maintaining road safety and effective cleaning techniques in volcanic ash environments.

show abstract

“…Studies since the 1980 Mount St Helens eruption (e.g. Blong 1984, Johnston 1997, Guffanti et al 2009, Horwell et al 2010, Wilson et al 2011, Dunn 2012, Stewart et al 2013, Blake et al 2016, 2017a demonstrate that volcanic ash frequently reduces skid resistance and covers markings on paved surfaces. Reduced visibility caused by airborne ash and the abrasion or cracking of vehicle windscreens are also common, and engine failure may result if vehicle air intake filters are not adequately maintained.…”

Section: Unisdr 2009mentioning

confidence: 99%

Improving volcanic ash fragility functions through laboratory studies: example of surface transportation networks

et al. 2017

View full text Add to dashboard Cite

Surface transportation networks are critical infrastructure that are frequently affected by volcanic ash fall. Disruption to surface transportation from volcanic ash is often complex with the severity of impacts influenced by a vast array of parameters including, among others, ash properties such as particle size and deposit thickness, meteorological conditions, pavement characteristics, and mitigation actions. Fragility functions are used in volcanic risk assessments to express the conditional probability that an impact or loss state will be reached or exceeded for a given hazard intensity. Most existing fragility functions for volcanic ash adopt ash thickness as the sole hazard intensity metric that determines thresholds for functional loss. However, the selection of appropriate hazard intensity metrics has been highlighted as a crucial factor for fragility function development and recent empirical evidence suggests that ash thickness is not always the most appropriate metric. We review thresholds of functional loss for existing published surface transportation (i.e. road rail, maritime and airport) fragility functions that use ash thickness. We then refine these existing functions through the application of results from a series of recent laboratory experiments, which investigate the impacts of volcanic ash on surface transportation. We also establish new fragility thresholds and functions, which applies ash-settling rate as a hazard intensity metric. The relative importance of alternative hazard intensity metrics to surface transportation disruption is assessed with a suggested approach to account for these in existing fragility functions. Our work demonstrates the importance of considering ash-settling rate, in addition to ash thickness, as critical hazard intensity metrics for surface transportation, but highlights that other metrics, especially particle size, are also important for transportation. Empirical datasets, obtained from both post-eruption field studies and additional laboratory experimentation, will provide future opportunities to refine fragility functions. Our findings also justify the need for rapid and active monitoring and modelling of various ash characteristics (i.e. not ash thickness alone) during volcanic eruptions, particularly as potential disruption to surface transportation can occur with only~0.1 mm of ash accumulation.

show abstract

Operation of Gas Turbine Engines in an Environment Contaminated With Volcanic Ash

Cited by 98 publications

References 10 publications

The thermal stability of Eyjafjallajökull ash versus turbine ingestion test sands

The thermal stability of Eyjafjallajökull ash versus turbine ingestion test sands

Impact of Volcanic Ash on Road and Airfield Surface Skid Resistance

Improving volcanic ash fragility functions through laboratory studies: example of surface transportation networks

Contact Info

Product

Resources

About