Academic Appointments


All Publications


  • Crystal aggregates record the pre-eruptive flow field in the volcanic conduit at Kilauea, Hawaii. Science advances DiBenedetto, M., Qin, Z., Suckale, J. 2020; 6 (49)

    Abstract

    Developing reliable, quantitative conduit models that capture the physical processes governing eruptions is hindered by our inability to observe conduit flow directly. The closest we get to direct evidence is testimony imprinted on individual crystals or bubbles in the conduit and preserved by quenching during the eruption. For example, small crystal aggregates in products of the 1959 eruption of Kilauea Iki, Hawaii contain overgrown olivines separated by large, hydrodynamically unfavorable angles. The common occurrence of these aggregates calls for a flow mechanism that creates this crystal misorientation. Here, we show that the observed aggregates are the result of exposure to a steady wave field in the conduit through a customized, process-based model at the scale of individual crystals. We use this model to infer quantitative attributes of the flow at the time of aggregate formation; notably, the formation of misoriented aggregates is only reproduced in bidirectional, not unidirectional, conduit flow.

    View details for DOI 10.1126/sciadv.abd4850

    View details for PubMedID 33277257

  • Wettability and capillary effects: Dynamics of pinch-off in unconstricted straight capillary tubes PHYSICAL REVIEW E Esmaeilzadeh, S., Qin, Z., Riaz, A., Tchelepi, H. A. 2020; 102 (2)
  • Two-phase multiscale numerical framework for modeling thin films on curved solid surfaces in porous media JOURNAL OF COMPUTATIONAL PHYSICS Qin, Z., Esmaeilzadeh, S., Riaz, A., Tchelepi, H. A. 2020; 413
  • Crystal Fractionation by Crystal-Driven Convection GEOPHYSICAL RESEARCH LETTERS Culha, C., Suckale, J., Keller, T., Qin, Z. 2020; 47 (4)
  • A locally second order symmetric method for discontinuous solution of Poisson's equation on uniform cartesian grids COMPUTERS & FLUIDS Qin, Z., Riaz, A., Balaras, E. 2020; 198
  • Flow-to-Sliding Transition in Crystal-Bearing Magma JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH Qin, Z., Suckale, J. 2020; 125 (2)
  • Direct numerical simulations of viscous suspensions with variably shaped crystals JOURNAL OF COMPUTATIONAL PHYSICS Qin, Z., Allison, K., Suckale, J. 2020; 401
  • Wettability and capillary effects: Dynamics of pinch-off in unconstricted straight capillary tubes. Physical review. E Esmaeilzadeh, S., Qin, Z., Riaz, A., Tchelepi, H. A. 2020; 102 (2-1): 023109

    Abstract

    We study the interfacial evolution of immiscible two-phase flow within a capillary tube in the partial wetting regime using direct numerical simulation. We investigate the flow patterns resulting from the displacement of a more viscous fluid by a less viscous one under a wide range of wettability conditions. We find that beyond a wettability dependent critical capillary number, a uniform displacement by a less viscous fluid can transition into a growing finger that eventually breaks up into discrete blobs by a series of pinch-off events for both wetting and nonwetting contact angles. This study validates previous experimental observations of pinch-off for wetting contact angles and extends those to nonwetting contact angles. We find that the blob length increases with the capillary number. We observe that the time between consecutive pinch-off events decreases with the capillary number and is greater for more wetting conditions in the displaced phase. We further show that the blob separation distance as a function of the difference between the inlet velocity and the contact line speed collapses into two monotonically decreasing curves for wetting and nonwetting contact angles. For the phase separation in the form of pinch-off, this work provides a quantitative study of the emerging length and timescales and their dependence on the wettability conditions, capillary effects, and viscous forces.

    View details for DOI 10.1103/PhysRevE.102.023109

    View details for PubMedID 32942359

  • Slug Stability in Flaring Geometries and Ramifications for Lava Lake Degassing JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH Qin, Z., Soldati, A., Santana, L., Rust, A. C., Suckale, J., Cashman, K. V. 2018; 123 (12): 10431–48
  • Bistability of buoyancy-driven exchange flows in vertical tubes JOURNAL OF FLUID MECHANICS Suckale, J., Qin, Z., Picchi, D., Keller, T., Battiato, I. 2018; 850: 525–50
  • Direct numerical simulations of gas-solid-liquid interactions in dilute fluids INTERNATIONAL JOURNAL OF MULTIPHASE FLOW Qin, Z., Suckale, J. 2017; 96: 34–47
  • Topology preserving advection of implicit interfaces on Cartesian grids JOURNAL OF COMPUTATIONAL PHYSICS Qin, Z., Delaney, K., Riaz, A., Balaras, E. 2015; 290: 219–38