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We propose an on-the-fly statistical learning method to make a qualitative reduced-order model of the dynamics of a premixed flame quantitatively accurate. This physics- informed data-driven method is based on the statistically optimal combination of (i) a reduced-order model of the dynamics of a premixed flame with a level-set method, (ii) high-quality data, which can be provided by experiments and/or high-fidelity simulations, and (iii) assimilation of the data into the reduced-order model to improve the prediction of the dynamics of the premixed flame. The reduced-order model learns the state and the parameters of the premixed flame on the fly with the ensemble Kalman filter, which is a Bayesian filter used in the data assimilation of high-dimensional dynamical systems, e.g., in weather forecasting. The proposed method and algorithm are applied to two test cases with relevance to reacting flow and instability. First, the capabilities of the framework are demonstrated in a twin experiment, where the assimilated data are produced from the same model as that used in prediction. Second, the assimilated data are extracted from a high-fidelity reacting-flow direct numerical simulation (DNS). The results are analyzed by using Bayesian statistics, which provide the uncertainties of the calculations. This method opens up new possibilities for on-the-fly optimal calibration of computationally cheap reduced-order models when experimental data become available, for example, from sensors.

Nowadays, much attention is payed to the development of renewable energy resources. Wind energy plays a major role in this issue. That is why there is a growing interest for improving the design process of wind turbines at many aspects. This study compares two types of offshore wind turbines structures, the monopile and the jacket structure, in their dependency on wave load characteristics’ variations. The examined wave characteristics are significant wave height and wave peak period. The jacket structure showed lower influence of increase of wave height to stresses in the cross section at the bottom of the structure compared to the monopile structure. The monopile structure showed slight dependency of stresses on increasing wave frequency, while the jacket structure showed nearly no dependency, due to its more complex geometry and higher stiffness.

ON 16 NOVEMBER 2000, the final report of the World Commission on Dams (WCD) was launched in London, in the presence of South Africa’s former president Nelson Mandela. This represented a remarkable milestone in the history of dam policy and politics. During its two-year existence, WCD had conducted the most extensive review of research and evidence regarding the planning, impacts, and management of large dams. It had engaged with numerous stakeholders around the globe. It also made comprehensive recommendations about how to improve dam planning and management.

This article addresses the problem that fluctuations in the torque of an internal combustion engine (ICE) lead to additional energy losses, as it causes fluctuations in the speed and kinetic energy of the car. These losses increase as the frequency of oscillations of the torque of the internal combustion engine approaches the frequency of free (natural oscillations) of the running gear of the car in the longitudinal direction. If there is an elastic connection between the traction force and the movement of the car, the movement of the latter can be represented as complex. At the same time, the portable movement is uniform, and the relative movement is oscillatory. This article presents the results of the study of these losses for cars with mechanical and combined electromechanical drive wheels. Analytical expressions are obtained, which allows to take into account additional energy losses including the tangential rigidity of the tire and the rigidity of the suspension in the longitudinal direction. When using a combined electromechanical drive of the drive wheels as well as in the case of a mechanical transmission of a car, the resonance is dangerous. But with the increase in the share of torque kem on the wheel generated by the electric motor, the relative additional energy losses for the movement of the car are reduced.

{"references": ["Kim H., Tadesse Y., Priya S., 2009, Energy Harvesting Technologies,\np3-4", "Curz Joao, 2008, Ocean Wave Energy, p1-4", "Zhu D., Beeby S., 2011, Energy Harvesting Systems, p1-3", "OECD, 2006, Energy Technology perspectives 2006: scenarios &\nstrategies to 2050, Organisation of Economic Cooperation &\nDevelopment, page 229-230.", "Khaligh A. and Onar Omer C., 2008, Energy Harvesting Solar, Wind, and\nOcean Energy Conversion System, pp223-230, pp250.", "Briney A., 2012, Waves - Ocean Waves, viewed at 10th April 2012,\n.", "Berteaux H. O., 1976, Buoy Engineering, The University of Michigan,\nUSA.", "Falnes, J 2007, \u00d4\u00c7\u00ffA review of wave-energy extraction-, ScienceDirect, vol.\n20, pp. 185-201", "Alaska Sea Grant, viewed at 16th April 2012,\n.\n[10] Robinson M. C., 2006, Renewable Energy Technologies for Use on the\nOuter Continental Shelf, National Renewable Energy Laboratory USA,\nviewed at 10th April 2012,\n.\n[11] Behrens, S, Heyward, J, Hemer, M, Osman, P 2011, \u00d4\u00c7\u00ffAssessing the wave\nenergy converter potential for Australian coastal regions-, Renewable\nEnergy, vol. 43, pp. 210-217.\n[12] Herbich, J 2000, Handbook of coastal engineering, Mcgraw-Hill\nprofessional.\n[13] Jefferys ER, 1980, Device characterization. In: Count BM (ed) Power\nfrom sea waves. Academic Press, pp 413-438."]} This paper presents an overview of the Ocean wave kinetic energy harvesting system. Energy harvesting is a concept by which energy is captured, stored, and utilized using various sources by employing interfaces, storage devices, and other units. Ocean wave energy harvesting in which the kinetic and potential energy contained in the natural oscillations of Ocean waves are converted into electric power. The kinetic energy harvesting system could be used for a number of areas. The main applications that we have discussed in this paper are to how generate the energy from Ocean wave energy (kinetic energy) to electric energy that is to eliminate the requirement for continual battery replacement.

This paper presents a research work carried out under the umbrella of the CASCADE project, which is a European FP7 research project which is developing facility-specific measurement-based energy action plans for the airport energy managers that are underpinned by Fault Detection Diagnosis (FDD). The paper first describes the context of the project then it focuses on Building Management Systems describing the current status of the technology and presenting an outlook on their future development. Then a Strengths Weakness Opportunity and Treads (SWOT) framework is defined with the aim of verifying the suitability of an installed BMS system to incorporate Fault Detection and Diagnosis (FDD) tools

{"references": ["M. Salamanca, F. Mondragon, J. R. Agudelo, P. Benjumea, and A. Santamaria, \"Variations in the chemical composition and morphology of soot induced by the unsaturation degree of biodiesel and a biodiesel blend,\" Combust. Flame, vol. 159, no. 3, pp. 1100\u20131108, 2012.", "P. Benjumea, J. R. Agudelo, and A. F. Agudelo, \"Effect of the degree of unsaturation of biodiesel fuels on engine performance, combustion characteristics, and emissions,\" Energy and Fuels, vol. 25, no. 1, pp. 77\u201385, 2011.", "A. A. Refaat, \"Correlation between the chemical structure of biodiesel and its physical properties,\" Int. J. Environ. Sci. Technol., vol. 6, no. 4, pp. 677\u2013694, 2009.", "H. K. Imdadul, H. H. Masjuki, M. A. Kalam, N. W. M. Zulkifli, M. Kamruzzaman, M. M. Shahin, and M. M. Rashed, \"Evaluation of oxygenated n-butanol-biodiesel blends along with ethyl hexyl nitrate as cetane improver on diesel engine attributes,\" J. Clean. Prod., vol. 141, pp. 928\u2013939, 2017.", "N. Yilmaz and A. Atmanli, \"Experimental assessment of a diesel engine fueled with diesel-biodiesel-1-pentanol blends,\" Fuel, vol. 191, pp. 190\u2013197, 2017.", "C. Pagliaro, \"A deeper look at diesel fuel,\" The Chemistry of the Diesel Engine, 2012. (Online). Available: https://chembloggreen1.wordpress.com/page/2/. )Accessed: 07-Nov-2017).", "O. Bennett, \"Biofuels,\" House Commons Libr., pp. 1\u20139, 2011.", "European Parliament, \"Directive 2009/28/EC of the European Parliament and of the Council of 23 April 2009,\" Off. J. Eur. Union, vol. 140, no. 16, pp. 16\u201362, 2009.", "Volkswagen Group, \"Biodiesel statement,\" 2010.\n[10]\tS. Schober and M. Mittelbach, \"Iodine value and biodiesel: Is limitation still appropriate?,\" Lipid Technol., vol. 19, no. 12, pp. 281\u2013284, 2007.\n[11]\tG. Knothe, \"Analyzing biodiesel: standards and other methods,\" J. Am. Oil Chem. Soc., vol. 83, no. 10, pp. 823\u2013833, 2006.\n[12]\tD. Rutz and R. Janssen, \"Overview and Recommendations on Biofuel Standards for Transport in the EU (Contribution to WP 3.2 and WP 5.5),\" Munchen, Germany, 2006.\n[13]\tL. F. Ramirez-Verduzco, J. E. Rodriguez-Rodriguez, and A. del Rayo Jaramillo-Jacob, \"Predicting cetane number, kinematic viscosity, density and higher heating value of biodiesel from its fatty acid methyl ester composition,\" Fuel, vol. 91, no. 1, pp. 102\u2013111, 2012.\n[14]\tA. Sch\u00f6nborn, \"Influence of the molecular structure of biofuels on combustion in a compression ignition engine,\" University College London, 2009.\n[15]\tB. Ham, R. Shelton, B. Butler, and P. Thionville, \"Calculating the lodine value for marine oils from fatty acid profiles,\" J. Am. Oil \u2026, no. 20, pp. 1445\u20131446, 1998.\n[16]\tM. J. Murphy, J. D. Taylor, and R. L. Mccormick, \"Compendium of Experimental Cetane Number Data,\" Natl. Renew. Energy Lab., no. August, pp. 1\u201348, 2004."]} Hardly any neat biodiesel satisfies the European EN14214 standard for compression ignition engine application. To satisfy the EN14214 standard, various additives are doped into biodiesel; however, biodiesel additives might cause other problems such as increase in the particular emission and increased specific fuel consumption. In addition, the additives could be expensive. Considering the increasing level of greenhouse gas GHG emissions and fossil fuel depletion, it is forecasted that the use of biodiesel will be higher in the near future. Hence, the negative aspects of the biodiesel additives will likely to gain much more importance and need to be replaced with better solutions. This study aims to satisfy the European standard EN14214 by blending the biodiesels derived from sustainable feedstocks. Waste Cooking Oil (WCO) and Animal Fat Oil (AFO) are two sustainable feedstocks in the EU (including the UK) for producing biodiesels. In the first stage of the study, these oils were transesterified separately and neat biodiesels (W100 & A100) were produced. Secondly, the biodiesels were blended together in various ratios: 80% WCO biodiesel and 20% AFO biodiesel (W80A20), 60% WCO biodiesel and 40% AFO biodiesel (W60A40), 50% WCO biodiesel and 50% AFO biodiesel (W50A50), 30% WCO biodiesel and 70% AFO biodiesel (W30A70), 10% WCO biodiesel and 90% AFO biodiesel (W10A90). The prepared samples were analysed using Thermo Scientific Trace 1300 Gas Chromatograph and ISQ LT Mass Spectrometer (GC-MS). The GS-MS analysis gave Fatty Acid Methyl Ester (FAME) breakdowns of the fuel samples. It was found that total saturation degree of the samples was linearly increasing (from 15% for W100 to 54% for A100) as the percentage of the AFO biodiesel was increased. Furthermore, it was found that WCO biodiesel was mainly (82%) composed of polyunsaturated FAMEs. Cetane numbers, iodine numbers, calorific values, lower heating values and the densities (at 15 oC) of the samples were estimated by using the mass percentages data of the FAMEs. Besides, kinematic viscosities (at 40 °C and 20 °C), densities (at 15 °C), heating values and flash point temperatures of the biomixture samples were measured in the lab. It was found that estimated and measured characterisation results were comparable. The current study concluded that biomixture fuel samples W60A40 and W50A50 were perfectly satisfying the European EN 14214 norms without any need of additives. Investigation on engine performance, exhaust emission and combustion characteristics will be conducted to assess the full feasibility of the proposed biomixture fuels.

In order to develop the technology of carbon dioxide at so-called supercritical state (sCO2) further, quick and reliable design tools for the different system components, e.g. centrifugal compressors, are required. In this study, a computer program is developed to predict the performance of centrifugal compressors with sCO2 as working fluid. This computer program is based on mean-line analysis, calculates the fluid parameters at selected sections of the meridional plane and plots the performance maps. So-called enthalpy loss coefficients are utilized to describe the difference between the isentropic and the polytropic process. In addition to previous studies, the presented model intends to predict the performance of sCO2 centrifugal compressor with a shrouded impeller and a vaneless diffuser. For this purpose, corresponding loss coefficients are incorporated. Subsequently, the predicted results of this work are compared and validated with computational fluid dynamics (CFD) and experimental results from the EU-project sCO2-HeRo. The prediction of the computer program fits within 5% deviation to the CFD results, and about 4% to the experimental results regarding to pressure ratio. Conference Proceedings of the European sCO2 Conference4th European sCO2 Conference for Energy Systems: March 23-24, 2021, Online Conference, p. 68