Infrastructure Engineering - Research Publications
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ItemArtificial neural networks for predicting the performance of heat pumps with horizontal ground heat exchangers(Frontiers Media SA, )A Ground Coupled Heat Pump (GCHP) is a highly energy efficient heating, ventilation, and air conditioning (HVAC) system that utilises the ground as the heat source when heating and as the heat sink when cooling. This paper investigates GCHP systems with horizontal Ground Heat Exchangers (GHEs) in the rural industry, exemplifying the technology for poultry (chicken) sheds in Australia. This investigation aims to provide an Artificial Neural Network (ANN) model that can be used for GCHP design at various locations with different climates. To this extent, a Transient System Simulation Tool (TRNSYS) model for a typical horizontal GHE applied in a rural farm was first verified. Using this model, over 700,000 hourly performance data items were obtained, covering over 80 different yearly loading patterns under three different climate conditions. The simulated performance data was then used to train the ANN. As a result, the trained ANN can predict the performance of GCHP systems with identical (multiple) GHEs even under climatic conditions (and locations) that have not been specifically trained for. Unlike other works, the newly introduced ANN model is accurate even with limited types of input data, with high accuracy (less than 5% error in most cases tested). This ANN model is 100 times computationally faster than TRNSYS simulations and 10,000 times faster than finite element models.
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ItemSupply chain risk management for projects: A review, a taxonomy, a framework, and a research agenda(University of Bath, 2024)This study investigates the critical role of supply chain risk management (SCRM) as a factor for growth and competitive advantage in project management. While there is extensive literature on risk management, there is a notable gap in the development of a comprehensive risk taxonomy tailored to project management supply chains. Through a systematic literature review of 50 scholarly articles, this paper categorizes and identifies prevalent supply chain risks and their potential impacts, which influence the entirety of project supply chains. It introduces a novel SCRM taxonomy, elucidating its significance in the context of project management. Additionally, the research proposes a future research agenda aimed at supporting the theoretical foundations of SCRM, thereby facilitating its formalization and strategic refinement. This endeavor enhances our understanding of SCRM’s key role in project management, providing a structure for future research and application across diverse industries, beyond the traditional focus on construction.
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ItemThe affordance of boundary objects for codified project learning sharing between communities of practice: Pilot study results and learnings for selected sustainability demonstration projects(University of Bath, 2024)Effective project-to-project learning can prevent projects from repeating the same mistakes however externalised knowledge sharing is necessary to overcome temporal, geographical and organisational barriers. Externalised sharing for this purpose requires the codification of knowledge relating to project learnings within boundary objects, where codification may be impacted by an array of complex considerations. Among these considerations is whether the capacity of the boundary object affords boundary spanning between communities of practice, where boundary-spanning capacity is influenced by the characteristics codified within the object. The grand-challenge context of sustainability demonstration projects provides an important case context for boundary spanning as these projects have knowledge sharing and learning as a central focus, key driver and intended outcome. While the application of boundary objects has been explored in a wide range of domains and cases, this article specifically considers the characteristics of boundary objects representing codified project learnings to afford project-to-project knowledge sharing, a focus which has not yet been studied in either the sustainability demonstration context or any other project-to-future learning organisation case context. An initial pilot study has been conducted with four sustainability demonstration case projects, with results and learnings to guide the refinement of future large-scale research design.
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ItemA dataset of direct observations of sea ice drift and waves in ice(NATURE PORTFOLIO, 2023-05-03)Variability in sea ice conditions, combined with strong couplings to the atmosphere and the ocean, lead to a broad range of complex sea ice dynamics. More in-situ measurements are needed to better identify the phenomena and mechanisms that govern sea ice growth, drift, and breakup. To this end, we have gathered a dataset of in-situ observations of sea ice drift and waves in ice. A total of 15 deployments were performed over a period of 5 years in both the Arctic and Antarctic, involving 72 instruments. These provide both GPS drift tracks, and measurements of waves in ice. The data can, in turn, be used for tuning sea ice drift models, investigating waves damping by sea ice, and helping calibrate other sea ice measurement techniques, such as satellite based observations.
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ItemSurface Wave Mixing Modifies Projections of 21st Century Ocean Heat Uptake(MDPI, 2023-03)Climate models do not explicitly account for the smaller scale processes of ocean surface waves. However, many large-scale phenomena are essentially coupled with the waves. In particular, waves enhance mixing in the upper ocean and thereby accelerate the ocean response to atmospheric changes. Here, we introduced a representation of wave-induced turbulent mixing into the one-way coupled ACCESS-OM2-025 ocean model to study its effect on ocean heat content throughout the 21st century under the RCP4.5 scenario. We made two projections on ocean heat uptake for the end of the century: one which accounts for wave-induced mixing (the ‘modified’ projection) and the other which does not (the ‘standard’ projection). Both projections showed upper ocean heat content to increase by more than 2.2 × 1022 J. This projected ocean heat uptake was reduced by about 3% in the modified projection. Whilst the inclusion of wave-induced mixing reduces projected ocean heat uptake globally, some areas are expected to warm considerably faster, particularly the North Atlantic sub-tropics, the Tasman Sea, the Sea of Japan, and parts of the South Atlantic.
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ItemAnalysis of the 20-Year Variability of Ocean Wave Hazards in the Northwest Pacific(MDPI, 2023-05-26)In the Northwest Pacific (NWP), where a unique monsoon climate exists and where both typhoons and extratropical storms occur frequently, hazardous waves pose a significant risk to maritime safety. To analyze the 20-year variability of hazardous waves in this region, this study utilized hourly reanalysis data from the ECMWF ERA5 dataset covering the period from 2001–2020, alongside the wave risk assessment method. The ERA5 data exhibits better consistency, in both the temporal and spatial dimensions, than satellite data. Although hazardous wind seas occur more frequently than hazardous swells, swells make hazardous waves travel further. Notably, the extreme wave height (EWH) shows an increasing trend in high- and low-latitude areas of the NWP. The change in meridional wind speeds is the primary reason for the change in the total wind speed in the NWP. Notably, the maximum annual increase rate of 0.013 m/year for EWH exists in the region of the Japanese Archipelago. This study elucidated the distributions of wave height intensity and wave risk levels, noting that the EWHs of the 50-year and 100-year return periods can reach 20.92 m and 23.07 m, respectively.
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ItemThe impact of spume droplets induced by the bag-breakup mechanism on tropical cyclone modeling(Frontiers Media SA, 2023-01-01)Spume, large-radius seawater droplets that are ejected from the ocean into the atmosphere, can exchange moisture and heat fluxes with the surrounding air. Under severe weather conditions, spume can substantially mediate air-sea fluxes through thermal effects and thus needs to be physically parameterized. While the impact made by spume on air-sea interactions has been considered in bulk turbulent air-sea algorithms, various hypotheses in current models have resulted in uncertainties remaining regarding the effect of spume on air-sea coupling. In this study, we extended a classic bulk turbulent air-sea algorithm with a “bag-breakup” physical scheme of spume generation parameterizations to include spume effects in a complicated numerical model. To investigate the impact of spume on air-sea coupling, we conducted numerical experiments in a simulation of Tropical Cyclone Narelle. We observed a significant improvement in the ability to model minimum central pressure and maximum sustained surface wind speed when including the bag-breakup spume scheme. In particular, the impact of the bag breakup–generated spume is observed in the intensity, structure, and size of the tropical cyclone system through the modulation of local wind speed (U10), wave height (Hs), and sea surface temperature.
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ItemEstimating the elastic modulus of landfast ice from wave observations(Cambridge University Press (CUP), 2023-01-01)Abstract Progress in our understanding of wave–ice interactions is currently hindered by the lack of in situ observations and information of sea-ice properties, including the elastic modulus. Here, we estimate the effective elastic modulus of sea ice using observations of waves in ice through the deployment of three open-source geophone recorders on landfast sea ice. From observations of low-frequency dispersive waves, we obtain an estimate of the effective elastic modulus in the range of 0.4–0.7 GPa. This is lower than the purely elastic modulus of the ice estimated at 1 GPa as derived from in situ beam experiments. Importantly, our experimental observation is significantly lower than the default value currently in use in wave models. While our estimate is not representative for all sea ice, it does indicate that considerably more measurements are required to provide confidence in the development of parameterizations for this complex sea-ice property for wave models.