Nonlinear Advection-Diffusion-Reaction Phenomena Involved in the Evolution and Pumping of Oil in Open Sea: Modeling, Numerical Simulation and Validation Considering the Prestige and Oleg Naydenov Oil Spill Cases.

The main goal of this article is to improve upon a previous model used to simulate the evolution of oil spots in the open sea and the effect of a skimmer ship pumping oil out from the spots. The concentration of the pollutant is subject to the effects of wind and sea currents, diffusion, and the pumping action of a skimmer (i.e., cleaning) ship that follows a pre-assigned trajectory. This implies that the mathematical model is of the advection-diffusion-reaction type. A drawback of our previous model was that diffusion was propagating with infinite velocity; in this article, we use an improved modeling relying on a nonlinear diffusion term, implying that diffusion propagates with finite velocity. To reduce numerical diffusion when approximating the advection part of the model, we consider second order discretization schemes with nonlinear flux limiters. We consider also absorbing boundary conditions to insure accurate results near the boundary. To reduce CPU time we use an operator-splitting scheme for the time discretization. Finally, we also introduce the modeling of coastlines and dynamic sources of pollutant. The novel approach we advocate in this article is validated by comparing our numerical results with real life measurements from the Oleg Naydenov and the Prestige oil spills, which took place in Spain in 2015 and 2002, respectively

Chemical tanker wreck simulation within the spanish economic exclusive zone (EZZ) : calculus and ship redesign to comply with actual standard regulations

The transport of hazardous cargo requires highly trained crews, following strict procedures and the efficient operation of safety systems. If one of the previous aspects will not be followed it could result in very serious consequences within an environmental and human health scope. In the present thesis, the consequences of both not following safety standard procedures and malfunctioning of safety systems are studied. The uninnerted atmosphere inside 22 cargo tanks in a chemical tanker, caused a series of explosions provoked by an electrostatic discharge when a compressed air hose used to blow down cargo pipes was disconnected. The accident caused a 2.1 km^2 oil and chemical spill and a 630 m^3 toxic chemical cloud. To minimize the effects of this accident a contingency plan was developed to effectively deploy inflatable booms in j shape and introduce 65.39 m^3 of cedre-approved dispersants. The accident consequences were simulated with oilmap, chemmap and sarmap, high-tech simulators rps asa kindly supplied the thesis author. Nevertheless, whenever talking about accidents the most important aspect is to learn from mistakes and avoid future incidents, for this manner a 35425 m^3/h inert gas system has been designed as well as a 154 m^3/h fixed washing system. Moreover, a thorough description of the use of both systems has taken place

A compositional Eulerian approach for modeling oil spills in the sea

We present a Compositional Eulerian model to forecast the evolution of oil spills in the sea. The model allows studying the fate of not only the oil concentration but also of each component (e.g., volatile, non-volatile, water in the oil). Therefore, the problem is formulated as a conservation equation for each component, plus an equation to estimate the age of the oil, which allows us to assess weathering processes (e.g., evaporation, natural dispersion, emulsion) and the associated changes in oil properties. We describe an efficient implementation, using second order numerical schemes for advection and nonlinear diffusion terms, to reduce numerical diffusion. We perform numerical experiments, based on real and synthetic cases, to illustrate and validate the capabilities of our model to forecast the evolution of oil spills and to perform environmental risk analysis in the case of a potential accident

Development of emergency response systems by intelligent and integrated approaches for marine oil spill accidents

Oil products play a pervasive role in modern society as one of the dominant energy fuel sources. Marine activities related to oil extraction and transportation play a vital role in resource supply. However, marine oil spills occur due to such human activities or harsh environmental factors. The emergency accidents of spills cause negative impacts on the marine environment, human health, and economic loss. The responses to marine oil spills, especially large-scale spills, are relatively challenging and inefficient due to changing environmental conditions, limited response resources, various unknown or uncertain factors and complex resource allocation processes. The development of previous research mainly focused on single process simulation, prediction, or optimization (e.g., oil trajectory, weathering, or cleanup optimization). There is still a lack of research on comprehensive and integrated emergency responses considering multiple types of simulations, types of resource allocations, stages of accident occurrence to response, and criteria for system optimizations. Optimization algorithms are an important part of system optimization and decision-making. Their performance directly affacts the quality of emergency response systems and operations. Thus, how to improve efficiency of emergency response systems becomes urgent and essential for marine oil spill management. The power and potential of integrating intelligent-based modeling of dynamic processes and system optimization have been recognized to better support oil spill responders with more efficient response decisions and planning tools. Meanwhile, response decision-making combined with human factor analysis can help quantitatively evaluate the impacts of multiple causal factors on the overall processes and operational performance after an accident. To address the challenges and gaps, this dissertation research focused on the development and improvement of new emergency response systems and their applications for marine oil spill response in the following aspects: 1) Realization of coupling dynamic simulation and system optimization for marine oil spill responses - The developed Simulation-Based Multi-Agent Particle Swarm Optimization (SA-PSO) modeling investigated the capacity of agent-based modeling on dynamic simulation of spill fate and response, particle swarm optimization on response allocation with minimal time and multi-agent system on information sharing. 2) Investigation of multi-type resource allocation under a complex simulation condition and improvement of optimization performance - The improved emergency response system was achieved by dynamic resource transportation, oil weathering and response simulations and resource allocation optimization. The enhanced particle swarm optimization (ME-PSO) algorithm performed outstanding convergence performance and low computation cost characteristics integrating multi-agent theory (MA) and evolutionary population dynamics (EPD). 3) Analysis and evaluation of influencing factors of multiple stages of spill accidents based on human factors/errors and multi-criteria decision making - The developed human factors analysis and classification system for marine oil spill accidents (HFACS-OS) framework qualitatively evaluated the influence of various factors and errors associated with the multiple operational stages considered for oil spill preparedness and response (e.g., oil spill occurrence, spill monitoring, decision making/contingency planning, and spill response). The framework was further coupled with quantitative data analysis by Fuzzy-based Technique for Order Preference by Similarity to Idea Solution (Fuzzy-TOPSIS) to enhance decision-making during response operations under multiple criteria. 4) Development of a multi-criteria emergency response system with the enhanced optimization algorithm, multi-mode resource transportation and allocation and a more complex and realistic simulation modelling - The developed multi-criteria emergency response system (MC-ERS) system integrated dynamic process simulations and weighted multi-criteria system optimization. Total response time, response cost and environmental impacts were regarded as multiple optimization goals. An improved weighted sum optimization function was developed to unify the scaling and proportion of different goals. A comparative PSO was also developed with various algorithm-improving methods and the best-performing inertia weight function. The proposed emergency response approaches in studies were examined by oil spill case studies related to the North Atlantic Ocean and Canada circumstances to analyze the modelling performance and evaluate their practicality and applicability. The developed optimization algorithms were tested by benchmarked functions, other optimization algorithms, and an oil spill case. The developed emergency response systems and the contained simulation and optimization algorithms showed the strong capability for decision-making and emergency responses by recommending optimal resource management or evaluations of essential factors. This research was expected to provide time-efficient, and cost-saving emergency response management approaches for handling and managing marine oil spills. The research also improved our knowledge of the significance of human factors/errors to oil spill accidents and response operations and provided improved support tools for decision making. The dissertation research helped fill some important gaps in emergency response research and management practice, especially in marine oil spill response, through an innovative integration of dynamic simulation, resource optimization, human factor analysis, and artificial intelligence methods. The research outcomes can also provide methodological support and valuable references for other fields that require timely and effective decisions, system optimizations, process controls, planning and designs under complicated conditions, uncertainties, and interactions

Risteilyaluksen matkustajahytin energiatehokkuuden parantaminen

The energy consumption of cruise ships has traditionally been improved by enhancing the properties of the ship’s hull or efficiency of its propulsion. Latest research has concentrated on the ship’s power plant and how to utilize most of the energy in the fuel. As reducing the energy consumption means reduced operating costs new research topics are searched all the time. In this thesis, the focus is on the passenger stateroom and its energy consumption. Despite the small consumption of one cabin, together the hundreds make a large impact on the ship’s energy consumption. Systems that are studied include solutions for the water system, ventilation system and electrical system. For the water system two different water recycling showers are studied and a waste water heat recovery system. Ventilation system solutions are replacing the cabin air handling unit with a more efficient type, adding automation to main ventilation and improving the cabin balcony door properties and shading to prevent solar radiation from heating the cabin. Electrical system solutions are cabin appliances and the cabin lighting. Some lighting automation is discussed as well. Ship is a delicate balanced system in which changes to any system may cause problems with other systems. During the research for this thesis many ideas and options were found unsuitable for the ship environment. Another problematic aspect is the ship owner’s unwillingness to invest in new and untested equipment. Research is based on estimated user profiles.Risteilyalusten energiankulutusta on perinteisesti pienennetty rungon ominaisuuksia parantamalla tai aluksen voimalinjan häviöitä vähentämällä. Viimeisimpiä tutkimuskohteita on ollut aluksen voimantuotanto ja se, kuinka siitä saadaan mahdollisimman paljon tehoa. Koska energiatehokkuuden parantuminen pienentää polttoaineen kulutusta, ja siten aluksen elinkaarikustannuksia, uusia tutkimuskohteita etsitään koko ajan. Tässä työssä keskitytään matkustajahyttiin ja sen järjestelmiin. Risteilyaluksen hytit ovat pieniä osasia, jotka yhdessä muodostavat ison osan laivan energiankulutuksesta. Laivan isoista järjestelmistä hytit liittyvät ilmastointijärjestelmään, vesijärjestelmään ja sähköjärjestelmään. Vesijärjestelmän ratkaisuja, joita tässä työssä tutkittiin, olivat erilaiset vettä kierrättävät suihkut ja lämmöntalteenotto harmaavedestä. Ilmanvaihtojärjestelmän ratkaisuina tutkittiin sekä automaation lisäämistä nykyiseen järjestelmään, että mahdollisuuksia vaihtaa hytin päätelaite tehokkaampaan. Samassa yhteydessä selvitettiin myös ikkunoiden ja hytin varjostuksen vaikutus tarvittavaan ilmanvaihtotehoon. Sähköjärjestelmiin puututtiin käyttölaitteiden ja valaistuksen kautta. Laiva on herkkä kokonaisuus, jossa muutokset yhteen järjestelmään saattavat heijastua toisiin järjestelmiin. Tämän diplomityön tutkimuksen aikana monet ratkaisut osoittautuivat laivakäyttöön sopimattomiksi. Toinen hankaluus järjestelmien käyttöön saamisessa on varustamoiden haluttomuus investoida uuteen ja aiemmin testaamattomaan kalustoon. Ratkaisujen energiansäästöpotentiaalia tutkittiin mallintamalla, käyttäen muodostettuja käyttäjäprofiileja

Systems management techniques and problems

Systems engineering and management applied to urban development, education, water management, inventory management, Saturn-Apollo project, and ecolog

NASA Thesaurus. Volume 1: Hierarchical listing

There are 16,713 postable terms and 3,716 nonpostable terms approved for use in the NASA scientific and technical information system in the Hierarchical Listing of the NASA Thesaurus. The generic structure is presented for many terms. The broader term and narrower term relationships are shown in an indented fashion that illustrates the generic structure better than the more widely used BT and NT listings. Related terms are generously applied, thus enhancing the usefulness of the Hierarchical Listing. Greater access to the Hierarchical Listing may be achieved with the collateral use of Volume 2 - Access Vocabulary

NASA thesaurus. Volume 1: Hierarchical Listing

There are over 17,000 postable terms and nearly 4,000 nonpostable terms approved for use in the NASA scientific and technical information system in the Hierarchical Listing of the NASA Thesaurus. The generic structure is presented for many terms. The broader term and narrower term relationships are shown in an indented fashion that illustrates the generic structure better than the more widely used BT and NT listings. Related terms are generously applied, thus enhancing the usefulness of the Hierarchical Listing. Greater access to the Hierarchical Listing may be achieved with the collateral use of Volume 2 - Access Vocabulary and Volume 3 - Definitions