CFD AND PHYSICAL MODELLING FOR THE MUSKRAT FALLS HYDROELECTRIC DEVELOPMENT PROJECT: A HYBRID APPROACH TO OPTIMIZING FLOW CONDITIONS AT THE POWERHOUSE FACILITY

摘要

The Muskrat Falls Hydroelectric Generating Facility being constructed by Nalcor Energy is located on the Lower Churchill River, approximately 270 km downstream of the Churchill Falls Hydroelectric Generating Station. The project is comprised of an 824 megawatt (MW) powerhouse facility situated on the south bank, along with gated and overflow spillways to convey water along the river up to the probable maximum flood (PMF) discharge. The development of the Muskrat Falls Project will meet the energy requirements for Newfoundland and Labrador, as well provide capacity for future industrial developments in Newfoundland and Labrador. The initial design of the powerhouse and spillway facilities was developed with the aid of three-dimensional computational fluid dynamics (CFD) modelling. Following this, a 1:70 scale undistorted, fixed-bed physical model of the study reach was used to: (ⅰ) verify the adequacy of the overall layout; (ⅱ) optimize the layout to improve performance and reduce construction costs; (ⅲ) develop stage-discharge relationships for the spillway structures; (iv) evaluate the hydraulic conditions during various construction phases; and (ⅴ) perform river closure tests to optimize the closure sequence and determine cofferdam rock sizes required to close the river. CFD was utilized throughout the physical model study to evaluate additional configurations and operating scenarios for the development. This hybrid approach, using numerical and physical models, was successfully used to evaluate various aspects of the design. The purpose of this paper is to show how the CFD and physical model results from testing of the powerhouse facility compared with one another.