Analysis of fuel consumption of modern electronically controlled high-speed marine engines

The paper presents thermal tests of modern electronically controlled high-speed main engines of Caterpillar 3500 series of marine vessels. During the thermotechnical tests, experimental studies were carried out to change the values of the actual fuel consumption depending on the engine load. The number of engines under study installed on sea tugs during 10 years of operation was 80 units. The accumulated experience in conducting experimental studies of the technical condition control by the CIP method of diagnostics will make it possible to move from the classical approaches of technical operation to the new ones included in the system of remote monitoring and control of ship technical means of autonomous ships in operation. The experimental research methodology includes a classic approach to conducting such tests and a modern approach with remote data transmission to the shipowner’s office. Studies have shown that different types of 3500 series engines have different actual fuel consumption values, but for each series, for example, 3512B, the scatter of points is small. The results of experimental studies of Caterpillar 3500 series engines made it possible to construct generalized dependences of the actual fuel consumption for each engine model separately. Experimental studies of ship technical means by the CIP method of diagnostics of sea vessels in operation are the basis for the control system of autonomous ships.

Constant inner potential DFT for modelling electrochemical systems under constant potential and bias

Electrochemical interfaces and reactions play a decisive role in e.g. clean energy conversion but understanding their complex chemistry remains an outstanding challenge. Constant potential or grand canonical ensemble (GCE) simulations are indispensable for unraveling the properties of electrochemical processes as a function of the electrode potential. Currently, constant electrode potential calculations at the density functional theory (DFT) level are carried out by fixing the Fermi level of the simulation cell. However, the Fermi level from DFT calculations does does not always reflect the experimentally controlled electrode potential or describe the thermodynamic independent variable in GCE-DFT i.e the electrochemical potential of an electron reservoir. Here we develop and implement the constant inner potential (CIP) method as a more robust and general approach to GCE-DFT simulations of electrochemical systems under constant potential or bias conditions. The CIP is shown to directly control the reservoir electron electrochemical potential making the method widely applicable in simulating electrochemical interfaces. We demonstrate that the CIP and Fermi level GCE-DFT approaches are equivalent for metallic electrodes and inner sphere reactions. The CIP method is shown to be applicable in simulating also semiconductor electrodes, outer sphere reactions, and a biased two-electrode cell for which the Fermi level approach does not reflect the experimental electrode potential. Unlike the Fermi level method, CIP does not require any electronic structure information as only the inner potential is needed, which makes the approach more compatible with classical force field or machine learning potentials. The CIP approach emerges as a general GCE DFT method to simulate (photo)electrochemical interfaces from first principles.

Evaluation of Field Applicability of Cast-in-Place Piles Using Surfactant Grout

In case of underground construction affected by groundwater, CIP (Cast-In-Place Pile) method is generally used to solve the geo-hydraulic problem. However, as this method has poor connectivity between piles, an auxiliary method for cut-off is required in many cases. In this study, a newly-developed cut-off wall (H-CIP) with no auxiliary method, by using surfactant grout (Hi-FA), which improves anti-washout and infiltration ability, is introduced, and the field applicability of H-CIP method is evaluated. CIP and H-CIP piles were installed with same ground conditions, and field and laboratory tests were conducted to verify the performance, respectively. As results, newly-contrived H-CIP method shows higher field performance for cut-off and strength than conventional CIP method.

The grain size(s) of Black Hills Quartzite deformed in the dislocation creep regime

A number of general shear experiments on Black Hills Quartzite (BHQ) in the dislocation creep regime, 5 of which have been analyzed previously using the CIP method (Heilbronner & Tullis, 2002 and 2006), are (re-)examined using the higher spatial and orientational resolution of EBSD. Segmentations based on c-axis orientation and on full crystallographic orientations are compared. Texture domains of preferred c-axis orientation are extracted and analyzed separately. Subdomains are recognized and their shape and size is related the kinematic framework and the original grains in the BHQ. Grain size analysis using a segmentation based on c-axis orientations is carried out for all, high and low strain samples of all regimes, and for a number of texture domains. The results are compared to the recrystallized quartz piezometer of Stipp & Tullis (2003), returning consistently higher values for stress or grain size. Possible causes for the discrepancy are texture dependence, grain scale strain, and dependence on the kinematic framework (in axial versus general shear experiments).