TY  - JOUR
PY  - 2017//
TI  - Wetting and spreading of molten volcanic ash in jet engines
JO  - Journal of physical chemistry letters
A1  - Song, Wenjia
A1  - Lavallee, Yan
A1  - Wadsworth, Fabian Ben
A1  - Hess, Kai-Uwe
A1  - Dingwell, Donald
SP  - 1878
EP  - 1884
VL  - 8
IS  - 8
N2  - A major hazard to jet engines posed by volcanic ash is linked to the wetting and spreading of molten ash droplets on engine component surfaces. Here, using the sessile drop method, we study the evolution of the wettability and spreading of volcanic ash. We employ rapid temperature changes up to 1040-1450 °C, to replicate the heating conditions experienced by volcanic ash entering an operating jet engine. In this scenario, samples densify as particles coalesce under surface tension until they form a large system-sized droplet (containing remnant gas bubbles and crystals) which subsequently spreads on the surface. The data exhibit a transition from a heterogeneous to a homogeneous wetting regime above 1315 °C as crystals in the drops are dissolved in the melt. We infer that both viscosity and microstructural evolution are key controls on the attainment of equilibrium in the wetting of molten volcanic ash droplets.<p />  <p>Language: en</p>
LA  - en
SN  - 1948-7185
UR  - http://dx.doi.org/10.1021/acs.jpclett.7b00417
ID  - ref1
ER  -