Journal of Cold Regions Engineering

Wave energy is an attractive source of renewable energy. In regions with a cold climate, for example, in the Baltic Sea, a good understanding of ice loads is vital for developing a reliable and cost-effective buoy for a wave energy converter (WEC). The first full-scale attempt was made to measure the vertical reaction force on a floating buoy connected to the WEC under the ice level interaction process. The force equation for a buoy connected to the WEC during the ice level interaction process is presented. It provides essential information on forces from the floating level of ice, which is very important for the design and construction of a buoy in regions with a cold climate.

This paper develops an analytical model for discharge assessment in straight channels with partial ice cover. The flow section of a partly covered channel was laterally divided into several homogeneous subsections, which were further classified into six basic elements according to the solid boundary conditions. In each basic element, the momentum balance, which accounts for momentum exchange between the adjacent subsections, was analyzed. Then, a linear system with a tridiagonal coefficient matrix was presented to estimate discharge in the partly covered channel. Experimental data collected from the literature were used to examine the performance of the proposed method and compare its accuracy with traditional methods for discharge assessment in composite or compound channels. The comparative results indicated that the proposed method produces satisfactory predictions, and the traditional methods were shown to be inappropriate for stage-discharge predictions in partly covered channels. In addition, the main parameters presented in the proposed model were discussed.

The Port of Nome, Alaska, contains a structure unique for coastal areas subject to large, wind-driven ice sheets or floes. The structure, an almost kilometer-long rubble-mound causeway, stretches perpendicularly out from the coastline to form the main stem of the port’s outer harbor. This paper presents findings from a case study that reconciles results from a somewhat uncommon combination of ice-tank tests and field observations of the causeway’s performance in floe-prone waters. The ice-tank tests, done more than 35 years ago, show that wind-driven ice floes could ride up and overtop the causeway, although without dislodging armor rock sized to withstand design-wave attack. Thirty years of observations, including several ice ride-up events, confirm that the causeway has indeed remained structurally sound, without loss of armor rock to wave or ice loads. A rock breakwater built to the east of the causeway now shields the causeway from floes moving from the east but aggravates ice problems at the entrance to and within the port.

A methodology for performing a snow drift transport analysis is provided that considers the demonstrated dependency of snow transport on approximately the fourth power of wind speed, giving much greater weight to high winds transporting snow. Data that have long sampling intervals (e.g., 3-h data) do not capture short-duration winds and tend to underpredict snow transport. This study introduces a way to account for the fluctuating component of the wind by including turbulence-intensity estimates. Its use was demonstrated via several cases studies. Based on available data, including turbulence intensity in the transport equations improved the estimate of the snow transport using 3- and 12-h data by 50%–100%. This study also illustrated the error in determining the transport wind direction from a wind rose. In an extreme case, the dominant transport direction was 180° out of phase with the prevailing wind direction determined by wind rose analysis. In two other case studies, a 50°–80° difference between the prevailing wind and dominate snow transport direction was not uncommon.