Magnetic-centrifugal drying of compressed air of pneumatic systems of machine-building enterprises

The article analyzes such basic methods of drying compressed air of pneumatic systems of machine-building enterprises as condensation, sorption, diffusion and force action and determines the advantages and disadvantages of each of these methods. It is noted that the method of force action on water particles due to the use of the centrifugal force allows you to remove only droplet moisture, and vaporous moisture remains in the compressed air. With further cooling of the compressed air, condensate reappears in it. Other methods are more efficient, but require consumables or complex devices for drying compressed air, which ultimately leads to an increase in the cost of such devices and an increase in operating costs. Based on the conducted analysis and on the fundamentals of theoretical mechanics, magnetic field theory and molecular physics, a method of magnetic-centrifugal drying of compressed air has been developed. The essence of the method is to use the Lorentz force, which acts on a water particle (a molecule, a dimer, a trimer, etc.) and coincides in the direction with the centrifugal force. When using the safe supply voltage of a 24 V solenoid that creates a magnetic field in which an electrically charged water particle moves, it is possible to increase the radial force (compared to the centrifugal force) acting on this particle by about 70 times. The authors also consider the methods of ionization of water particles that allow knocking out electrons from their outer shells. Experimental studies conducted on a mock-up sample showed a fairly high efficiency of this method, since it was possible to achieve the 3rd class of purity according to ISO 8573-1: 2001.

Turnover Time of the East Sea (Sea of Japan) Meridional Overturning Circulation

The East Sea (ES; Sea of Japan) meridional overturning circulation (MOC) serves as a crucial mechanism for the transportation of dissolved, colloidal, and suspended particulate matters, including pollutants, on the surface to deep waters via thermohaline circulation. Therefore, understanding the structure of the ES MOC is critical for characterizing its temporal and spatial distribution. Numerous studies have estimated these parameters indirectly using chemical tracers, severely limiting the accuracy of the results. In this study, we provide a method for directly estimating the turnover times of the ES MOC using the stream functions calculated from HYbrid Coordinate Ocean Model (HYCOM) reanalysis data by averaging the flow pattern in the meridional 2-D plane. Because the flow pattern is not consistent but various over time, three cases of stream function fields were computed over a 20-year period. The turnover time was estimated by calculating the time required for water particles to circulate along the streamlines. In the cases of multiple (two or three) convection cells, we considered all possible scenarios of the exchange of water particles between adjacent cells, so that they circulated over those cells until finally returning to the original position and completing the journey on the ES MOC. Three different cell cases were tested, and each case had different water particle exchange scenarios. The resulting turnover times were 17.91–58.59 years, 26.41–37.28 years, and 8.68–45.44 years for the mean, deep, and shallow convection cases, respectively. The maximum turnover time, namely 58.59 years, was obtained when circulating the water particle over all three cells, and it was approximately half of that estimated by the chemical tracers in previous studies (∼100 years). This underestimation arose because the streamlines and water particle movement were not calculated in the shallow (<300 m) and deep areas (>3,000 m) in this study. Regardless, the results of this study provide insight into the ES MOC dynamics and indicate that the traditional chemical turnover time represents only one of the various turnover scenarios that could exist in the ES.

The Effects on Water Particle Velocity of Wave Peaks Induced by Nonlinearity under Different Time Scales

The water particle velocity of the wave peaks is closely related to the wave load borne by offshore structures. It is of great value for marine disaster prevention to study the water particle velocity of nonlinear extreme waves represented by Freak waves. This study applies the High-order Spectral Method (HOS) numerical model to analyze the characteristics and influencing factors of the water particle velocity of Freak wave peak with two different generation mechanisms under the initial condition of a weakly modulated Stokes wave train. Our results show that the water particle velocity of the wave peak increases linearly with wave height and initial wave steepness in the evolution stage of modulation instability. While in the later stage, the relationship becomes exponential. Under the condition of similar wave heights, the deformation degrees of Freak waves with different generation mechanisms are distinct, the deformation degree of modulation instability stage is smaller than that of the later stage. The water particle velocity of the wave peaks increases with the deformation degrees. Furthermore, the correlation between wave peak height and water particle velocity is a quadratic function. This provides a theoretical basis for further understanding of nonlinear waves and the prediction of marine disasters.

Numerical Simulation of a Rectangular Clarifier Using Drift-Flux Model in OpenFOAM

A computation fluid dynamic (CFD) simulation of a rectangular clarifier is performed in this study using a drift-flux model in OpenFOAM CFD code. Using this model with turbulence model, the key characteristics (re-circulation and sedimentation) of water-particle mixture flow in a rectangular clarifier are reasonably reproduced. A fairly good agreement is obtained between the simulation results and experimental data of the velocity profiles. Thus, with the demonstrated capability of this CFD model for the prediction of hydrodynamic and sedimentation behavior of water-particle mixture flow, several design issues such as the determination of the best location of baffle in a clarifier can be investigated and addressed. This method can not only provide general conceptual information at the initial design stage but can also be used to perform analysis of different configurations and the effect of changes in operational parameters.

DEVELOPMENT OF WAVE POWER GENERATION SYSTEM SUITABLE FOR INNER BAY

With the increasing demand for renewable energy in the world, research contributing to the improvement of the technology level of wave power generation is essential. The authors have been developed a wave power generation system using port facilities in inner bays with high energy-consuming cities. In this study, the relationship between the rotational characteristics of a Savonius water turbine and the water particle velocity was quantitatively evaluated under the calm conditions of the inner bay, such as wave motion, flow, and coexistence of wave and current. According to the experimental results, it is found that the relationship between the rotational circumferential speed and the water particle velocity of the water turbine installed in a wave field tends to be different from that in a flow field and is evaluated by different equations. In addition, the relationship between circumferential velocity and the water particle velocity has also been formulated when installed in a wave-current coexistence field.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/KX0XBFuao48

Age of Water Particles as a Diagnosis of Steady-State Flows in Shallow Rectangular Reservoirs

The age of a water particle in a shallow man-made reservoir is defined as the time elapsed since it entered it. Analyzing this diagnostic timescale provides valuable information for optimally sizing and operating such structures. Here, the constituent-oriented age and residence time theory (CART) is used to obtain not only the mean age, but also the water age distribution function at each location. The method is applied to 10 different shallow reservoirs of simple geometry (rectangular), in a steady-state framework. The results show that complex, multimodal water age distributions are found, implying that focusing solely on simple statistics (e.g., mean or median age) fails to reflect the complexity of the actual distribution of water age. The latter relates to the fast or slow pathways that water particles may take for traveling from the inlet to the outlet of the reservoirs.