Towards a Hydrothermal Eruption Flow Model
by
Tammy Smith
Institute of Fundamental Sciences - Mathematics, Massey University
Coauthors: Robert McKibbin

Hydrothermal eruptions constitute one of a number of hazards associated with the development of geothermal fields. They are violent events ejecting a mixture of water, steam and rock particles without warning. Understanding the physical mechanisms which drive these events through the application of mathematical modelling techniques is essential to any assessment of the risks.

The primary process which drives a hydrothermal eruption is the boiling of water. In this talk I will examine the behaviour of a ``boiling front'' as it moves through a porous medium. The progression of this front will be llustrated through both numerical and physical experiments.

The principles of conservation of mass, momentum and energy are used to model the flow. A set of non linear partial differential equations governing transient mass and energy transport is obtained. In one horizontal dimension, these can be reduced to a simpler set of ordinary differential equations by use of a similarity variable. The numerical solution of the resulting equations provides a description of the advancement of the boiling front.

Initial results from a horizontal boiling experiment are presented for comparison with numerical solution. In this experiment, boiling is initiated at one end of a saturated core. One-dimensional liquid saturation distributions are then found along the porous medium sample using nuclear magnetic resonance imaging, providing a picture of the progression of the boiling front as it moves through the core.

Date received: June 3, 1999

Copyright © 1999 by the author(s). The author(s) of this document and the organizers of the conference have granted their consent to include this abstract in Atlas Conferences Inc. Document # cacc-35.