3D modelling of ice-covered flows in the vicinity of a deep hole in the East Channel of the Mackenzie Delta, N.W.T.

Abstract

The discovery of vast quantities of hydrocarbons during exploration of the Mackenzie Delta has led to the detection of numerous anomalous deep holes in various delta channels in the past four decades. The proposed pipeline crossing from the Mackenzie Delta to northern Alberta has renewed interest in studying the stability of these deep holes. The main goal of this research project was to study ice-covered flow velocity and bed shear stress distributions using a previously calibrated computational fluid dynamics (CFD) model for a 30 m deep hole in the East Channel of the Mackenzie Delta to provide an initial assessment of its stability. In this study, a previously developed 3D CFD model using the FLUENT code with the renormalization group theory (RNG) k-ε turbulence closure model with nonequilibrium wall functions was adapted to represent ice-covered flow conditions for the study reach. The numerical model was applied to simulate four flow conditions (500, 720, and 1000 m3/s along with a moving ice cover during a flow rate of 720 m3/s). Results indicated that a single vortex was formed near the inner bend above the hole and deposition may be a key process occurring during ice-covered flow conditions.