Collaborative Research: Quantifying the Emplacement of Channeled Flow Using Experimental, Analytical and Numerical Analyses

虽然通道状熔岩流在整个太阳系中很常见，但通道形态、喷发和侵位参数以及熔岩性质之间的关系还不是很清楚。我们先前研究的结果，将分析模型与精心控制的实验室模拟相结合，提出了许多用现有数据无法解决的问题。我们目前的建议通过从额外的实验室模拟收集数据来解决这些限制，特别是分离基础坡度和坡折对河道发育的影响、流变学的影响以及依赖温度的粘度对河道形态的影响。这将通过使用聚乙二醇(一种牛顿流体，粘度随温度变化)、高岭土充填的聚乙二醇(宾汉流体，粘度随温度变化)和高岭土泥浆(等温宾汉流体)在实验室中在不同的下伏坡度(1度-50度)上产生沟道流来实现。将使用注入流动中的中性浮力彩色微珠作为示踪剂仔细测量流道实验室流动中的速度分布。Sakimoto博士开发的计算流体动力学(CFD)流动模拟将进行修改，以处理实验室流动中发现的条件。将进行初步的CFD模拟，以了解不均匀的温度分布、从聚乙二醇罐和罐底到实验室环境的热损失以及聚乙二醇向周围蔗糖溶液的扩散等影响在实验室流动中的重要性。Gregg博士进行的模拟流动的形态参数将被测量，用于验证和改进CFD模拟结果。反过来，CFD模拟将被用来充分描述和理解实验室中主导流动放置和冷却的物理过程。这些结果将与天然玄武岩熔岩流进行测试，例如1984年夏威夷莫纳罗亚火山喷发，以及目前夏威夷基拉韦厄火山Pu‘u O’o喷发期间产生的较小的Pahoehoe水道。

GreggEAR-0001295Although channeled lava flows are common throughout the solar system, relations between channel morphology, eruption and emplacement parameters, and lava properties are not well understood. Results from our previous study, combining analytical models with carefully controlled laboratory simulations raised many questions that could not be addressed withavailable data. Our current proposal addresses these limitations by collecting data from additional laboratory simulations, specifically to isolate the effects of underlying slope and slope breaks on channel development, the effects of rheology, and the effects of temperature-dependent viscosities on channel morphology. This will be accomplished by using PEG (a Newtonian fluid with a temperature-dependent viscosity), kaolin-charged PEG (a Bingham fluid with a temperature-dependent viscosity) and kaolin slurries (an isothermal Bingham fluid) to generate channeled flows on different underlying slopes (1degree-50 degrees) in the laboratory. Velocity distributions within channeled laboratory flows will be carefully measured using neutrally buoyant colored beads injected into the flow as tracers. Computational fluid dynamics (CFD) flow simulations developed by Dr. Sakimoto will be modified to treat the conditions found in laboratory flows. Preliminary CFD simulations will be run to understand the significance in laboratory flows of such effects as non-homogenous temperature distributions, heat loss from the PEG and tankbottom to the laboratory environment, and diffusion of PEG into the surrounding sucrose solution. Morphologic parameters from the simulated flows conducted by Dr. Gregg will be measured used to validate and refine CFD simulation results. The CFD simulations, in turn, will be used to fully characterize and understand the physical processes that dominate flowemplacement and cooling in the laboratory. These results will be tested against natural basaltic lava flows, such as the 1984 Mauna Loa, Hawaii eruption and smaller pahoehoe channels produced during the current eruption of Pu'u O'o at Kilauea volcano, Hawaii.