22 Nov 2021

Artificial Ground Freezing Using Solar-Powered Thermosyphons

Abstract: Thermosyphons are an artificial ground-freezing technique that has been used to stabilize permafrost since the 1960s. The largest engineered structure that uses thermosyphons to maintain frozen ground is the Trans Alaska Pipeline, and it has over 124,000 thermosyphons along its approximately 1300 km route. In passive mode, thermosyphons extract heat from the soil and transfer it to the environment when the air temperature is colder than the ground temperature. This passive technology can promote ground cooling during cold winter months. To address the growing need for maintaining frozen ground as air temperatures increase, we investigated a solar-powered refrigeration unit that could operate a thermosyphon (nonpassive) during temperatures above freezing. Our tests showed that energy generated from the solar array can operate the refrigeration unit and activate the hybrid thermosyphon to artificially cool the soil when air temperatures are above freezing. This technology can be used to expand the application of thermosyphon technology to freeze ground or maintain permafrost, particularly in locations with limited access to line power.

5 Oct 2021

Installation Resilience in Cold Regions Using Energy Storage Systems

Abstract: Electrical energy storage (EES) has emerged as a key enabler for access to electricity in remote environments and in those environments where other external factors challenge access to reliable electricity. In cold climates, energy storage technologies face challenging conditions that can inhibit their performance and utility to provide electricity. Use of available energy storage technologies has the potential to improve Army installation resilience by providing more consistent and reliable power to critical infrastructure and, potentially, to broader infrastructure and operations. Sustainable power, whether for long durations under normal operating conditions or for enhancing operational resilience, improves an installation’s ability to maintain continuity of operations for both on- and off-installation missions. Therefore, this work assesses the maturity of energy storage technologies to provide energy stability for Army installations in cold regions, especially to meet critical power demands. The in-formation summarized in this technical report provides a reference for considering various energy storage technologies to support specific applications at Army installations, especially those installations in cold regions.

4 May 2021

Ice Fog Monitoring Near Fairbanks, AK

ABSTRACT:  Ice fog events, which occur during the Arctic winter, result in greatly decreased visibility and can lead to an increase of ice on roadways, aircraft, and airfields. The Fairbanks area is known for ice fog conditions, and previous studies have shown these events to be associated with moisture released from local power generation. Despite the identified originating mechanism of ice fog, there remains a need to quantify the environmental conditions controlling its origination, intensity, and spatial extent. This investigation focused on developing innovative methods of identifying and characterizing the environmental conditions that lead to ice fog formation near Fort Wainwright, Alaska. Preliminary data collected from December 2019 to March 2020 suggest that ice fog events occurred with temperatures below −34°C, up to 74% of the time ice fog emanated from the power generation facility, and at least 95% of ice particles during ice fog events were solid droxtals with diameters ranging from 7 to 50 µm. This report documents the need for frequent and detailed observations of the meteorological conditions in combination with photographic and ice particle observations. Datasets from these observations capture the environmental complexity and the impacts from energy generation in extremely cold weather conditions.

1 Dec 2020

Snow-Covered Obstacles’ Effect on Vehicle Mobility

ABSTRACT:  The Mobility in Complex Environments project used unmanned aerial systems (UAS) to identify obstacles and to provide path planning in forward operational locations. The UAS were equipped with remote-sensing devices, such as photogrammetry and lidar, to identify obstacles. The path-planning algorithms incorporated the detected obstacles to then identify the fastest and safest vehicle routes. Future algorithms should incorporate vehicle characteristics as each type of vehicle will perform differently over a given obstacle, resulting in distinctive optimal paths. This study explored the effect of snow-covered obstacles on dynamic vehicle response. Vehicle tests used an instrumented HMMWV (high mobility multipurpose wheeled vehicle) driven over obstacles with and without snow cover. Tests showed a 45% reduction in normal force variation and a 43% reduction in body acceleration associated with a 14.5 cm snow cover. To predict vehicle body acceleration and normal force response, we developed two quarter-car models: rigid terrain and deformable snow terrain quarter-car models. The simple quarter models provided reasonable agreement with the vehicle test data. We also used the models to analyze the effects of vehicle parameters, such as ground pressure, to understand the effect of snow cover on vehicle response.

1 Sep 2020

PUBLICATION NOTICE: Seasonal Effects on Vehicle Mobility: High-Latitude Case Study

Abstract: Seasonality plays a key role in altering the terrain of many military operating environments. Since seasonality has such a large impact on the terrain, it needs to be properly accounted for in vehicle dynamics models. This work outlines a variety of static and dynamic seasonal terrain conditions and their impacts on vehicle mobility in an austere region of Europe. Overall the vehicles performed the best in the dry season condition. The thaw season condition had the most drastic impact on mobility with all but the heavy tracked vehicle being almost completely NOGO in the region. Overall, the heavy tracked vehicle had the best performance in all terrain conditions. These results highlight the importance of incorporating seasonal impacts on terrain into NRMM or any vehicle dynamics model. Future work will focus on collecting more data to improve the empirical relationships between vehicles and seasonal terrain conditions, thereby allowing for more accurate speed predictions.

13 May 2020

PUBLICATION NOTICE: Assessment for Soil Reuse Standards at McMurdo Station

Abstract:  The soils at McMurdo Station in Antarctica contain hydrocarbons derived from accidental fuel spills and industrial development. The current practice for contaminated soils is to remove any material with concentrations greater than 100 mg/kg of total petroleum hydrocarbons (TPH) and to transport them to the United States for disposal. Any soils that contain concentrations of TPH less than 100 mg/kg can be reused on-site. While this is the current standard practice, there remains little evidence to verify that 100 mg/kg is an appropriate reuse standard. Moreover, the current practice is based on the guidelines for cleanup values in California (the port of entry where the soils are currently shipped for treatment and disposal), which has few environmental similarities with Antarctica. In the present study, we investigate current regulations for cleanup and soil reuse in U.S. states, Canadian territories, and other countries with cold climates. We also discuss case studies from Arctic and Antarctic regions where soil has been reused after treatment. Additionally, we present a site conceptual model for risk assessment based on known site information and recommend future focus areas for addressing hydrocarbon-contaminated soils at McMurdo Station.

9 Aug 2019

PUBLICATION NOTICE: SnowMicroPenetrometer Applications for Winter Vehicle Mobility

The US Army Engineer Research and Development Center has published the report/note described and linked below. Approved for public release; distribution is unlimited.Report Number:ERDC/CRREL TR-19-14Title:SnowMicroPenetrometer Applications for Winter Vehicle MobilityAuthor(s):Tate G. Meehan, Hans-Peter Marshall, Elias J. Deeb, and Sally A.