Intake Channels Research Articles

Composite Intake Ports Interference Mechanism and Application in Dual Intake Channels of the Opposed-Piston Diesel Engine

With the development of control technology, the uniflow scavenging opposed-piston (USOP) diesel engine has shown unique advantages in energy savings and emission reductions. Due to the uniflow scavenging process, unstable scavenging performance has become the key problem in the development process of the USOP diesel engine, and the intake structure is an effective method for regulating scavenging performance. This study verifies the simulation model based on experimental data and then analyzes the influence of the intake port structure through simulations. On the one hand, this study explores the interference mechanism and application rules of two structures: composite intake ports and dual independent intake ports. The results show that the external alignment structure should be used under all operating conditions for composite intake ports. For dual independent intake ports, the internal alignment structure should be used at high swirl strength, and the external alignment structure should be used at low swirl strength. On the other hand, the dual independent intake ports matching the dual intake channels can improve scavenging performance while reducing supply power. The conclusion provides a reference for the design of the intake structure of the USOP diesel engine from many aspects.

D1-Tyr246 and D2-Tyr244 in photosystem II: Insights into bicarbonate binding and electron transfer from QA•− to QB

In photosystem II (PSII), D1-Tyr246 and D2-Tyr244 are symmetrically located at the binding site of the bicarbonate ligand of the non-heme Fe complex. Here, we investigated the role of the symmetrically arranged tyrosine pair, D1-Tyr246 and D2-Tyr244, in the function of PSII, by generating four chloroplast mutants of PSII from Chlamydomonas reinhardtii: D1-Y246F, D1-Y246T, D2-Y244F, and D2-Y244T. The mutants exhibited altered photoautotrophic growth, reduced PSII protein accumulation, and impaired O2-evolving activity. Flash-induced fluorescence yield decay kinetics indicated a significant slowdown in electron transfer from QA•− to QB in all mutants. Bicarbonate reconstitution resulted in enhanced O2-evolving activity, suggesting destabilization of bicarbonate binding in the mutants. Structural analyses based on a quantum mechanical/molecular mechanical approach identified the existence of a water channel that leads to incorporation of bulk water molecules and destabilization of the bicarbonate binding site. The water intake channels, crucial for bicarbonate stability, exhibited distinct paths in the mutants. These findings shed light on the essential role of the tyrosine pair in maintaining bicarbonate stability and facilitating efficient electron transfer in native PSII.

How does hotline and incident management stack up in the financial services industry? An analysis of comparative metrics

An efficient and trusted mechanism by which employees can anonymously or confidentially report allegations of suspected or actual misconduct is the hallmark of a well-designed compliance programme. Yet, every industry will have different metrics related to their reporting processes and systems. There is not a ‘right’ answer because all metrics will be influenced by the risk areas facing each industry. The finance sector is no exception. So, what does the data show for the finance sector and how can the data be used to impact programme effectiveness? To answer this question, in 2023, NAVEX®, a provider of governance, risk and compliance information system software and services, examined financial-industry specifics within a large global data set of anonymised hotline and incident management metrics. This research, published here for the first time, follows the release of NAVEX's 2023 ‘Hotline & Incident Management Benchmark Report’ — an annual, publicly available analysis of hotline reporting data generated through the intake channels NAVEX provides to its customers. This research publication, published in March, involved a total of 1.52 million reports worldwide. Financial services was the third-most represented sector across the larger benchmark report. Comparing financial services to global benchmarks, it appears the industry is outperforming other sectors in several key incident management metrics. Yet for individual financial firms, the industry-specific benchmark data revealed in this analysis could provide a more refined look into the ways organisations can compare their programmes to their industry peers. Overall, the financial services industry received more reports per 100 employees, fewer anonymous reports, and were consistently closing cases even with a different mix of issue types, ie more business-related issues than other industries.

Operating indicators in diesels with reduced heat and energy losses

The foregoing explains the experimentally established fact that in a heat-insulated diesel engine, diffusion combustion is of great importance - both in terms of the share of heat release and the duration of combustion. To compensate for the decrease in the efficiency of a thermally insulated diesel engine due to an increase in the duration of combustion, the injection advance is increased. The economic effect achieved in this way by increasing the maximum cylinder pressure cannot be considered due to thermal insulation. For typical compression end temperatures in a thermally insulated diesel engine, diffusion combustion, especially in the near-wall layers, is limited by transfer processes. This fact, in addition to the need to eliminate re-enriched zones in the near-wall layers, urgently requires additional turbulization of the working fluid during mixture formation and combustion in thermally insulated engines. The difficulty in solving this problem lies in the fact that one of the most important turbulence generators is the intake process, and one of the most effective solutions is special intake channels. However, the averaged motion and turbulence in the combustor decay significantly during compression. This process is enhanced in a thermally insulated diesel engine due to an increase in the molecular viscosity of the air. The same applies to the generation of turbulence at the end of compression-beginning of expansion. Thus, turbulization of the charge in the combustion chamber of a thermally insulated diesel engine is an urgent problem.

Species diversity of phyto- and zooplankton in the water bodies of Kharanorskaya State District Power Plant, Transbaikalia (according to 2019 data)

We described the taxonomic structure of planktonic associations in the water bodies of Kharanor State District Power Plant (cooling pond, water supply, drainage, and water intake channels of Kharanor reservoir located in the arid zone of the south-eastern Transbaikalia in a highly continental climate). Hydrobiological researches were conducted in April, July, and October 2019. We identified 141 algal taxa ranked below the genus, representing the divisions of Cyanobacteria (15 taxa), Bacillariophyta (41), Chrysophyta (10), Cryptophyta (3), Dinophyta (4), Charophyta (8), Chlorophyta (56), and Euglenophyta (4), and 52 zooplankton taxa, including 28 species and subspecies of Rotifera, 15 species of Cladocera, and 9 species of Copepoda. In the cooling reservoir, the plankton community included 135 phytoplankton taxa and 38 zooplankton species; 58 algal taxa and 27 invertebrate species were sampled in the water supply channel, 50 taxa and 26 species were sampled in the drainage channel, and 94 taxa and 24 species were collected from water intake channel respectively. Six diatom species (Stephanodiscus hantzschii, Nitzschia sigmoidea, Fragilaria radians, Asterionella formosa, Ulnaria ulna) and four zooplankton species (rotifers Asplanchna priodonta and crustaceans Daphnia galeata, Bosmina longirostris, Thermocyclops crassus) occurred in all water bodies during the entire study period.

Numerical study of intake flow field inside the high-speed refrigeration scroll compressor with spiral suction channels in the motor rotor

To control the temperature of the electric motor, the suction gas is introduced flowing through the motor in hermetic scroll compressors. For high-speed compressors, this flow resistance is high, which results in decreasing of the efficiency. In this paper, spiral flow channels were designed inside the motor rotor to decrease the suction flow resistance and increase the refrigerant flow rate inside the scroll compressor. Simulation of the suction flow through the motor was carried out. Two structure of straight and spiral intake channels were brought into the simulation model, under 3000 rpm, 5000 rpm, 7000 rpm and 9000 rpm. The results showed that the spiral channels could increase the refrigerant flow rate inside the motor rotor and the suction pressure of the compressor, and with the increase of the motor speed, the effect of the intake supercharging improved. At 9000 rpm, the suction pressure at the suction port of the compressor increased by about 4% by using spiral channels, while the mass flow rate increased by about 6%. The increases of total refrigerant flow rate in spiral channels are mainly due to the increase in unblocked channels. The size and the layout of the balance weight have a great effect on intake flow.

Using the Submerged vanes to control the sediment entering branch channel with 30° angle with the direction of the main channel

A common problems faced by the side intake channels are sedimentation and sediment entry. These cause problems as limiting the flow ability in irrigation channels, and threatening to waterway block when the water level is low. This laboratory study was conducted to find out the effect of using one-row immersed vans in the main channel to control the sediments amount of entering the intake channel at an angle with two sand concentrations at granular diameter rate ( = 0.5mm). The first concentration flow rate was (1.8 ) And the second (2.22 ). The results showed that the use of a single row of submerged vans reduces the sediment amount that entered the intake channel by (35-65)% of the total sediments that were fed by the feeder channel for both concentrations. This indicates that use of submerged vans has a positive role in entry process and sediment transfer to branched channels.

Characteristics of inflow and subsidence turbidity in water intake channels

The article deals with the processes of turbidity, infiltration and sedimentation of mud, the annual volume of turbidity in the water intake without a dam from the Amu Darya to the Amu-Bukhara Canal. It is established that the decrease in water consumption, turbidity and transparency of the flow along the length of the intake channels is mainly due to the level of water consumption, turbidity of the river and the amount of water flowing through the main ABMC facility. As a result of the reconstruction of the main structure and the ABMC canal with the widespread use of hydro-mechanization devices, it became possible to carry out such water consumption. As the volume of water intake increased, so did the amount of turbidity that came with the water. A large amount offloating and attracting silt coming from the river will sink into the channel bed, reducing the living cross-section and carrying capacity of the channel.

Themis regulates metabolic signaling and effector functions in CD4+ T cells by controlling NFAT nuclear translocation

Themis is a T cell lineage-specific molecule that is involved in TCR signal transduction. The effects of germline Themis deletion on peripheral CD4+ T cell function have not been described before. In this study, we found that Themis-deficient CD4+ T cells had poor proliferative responses, reduced cytokine production in vitro and weaker inflammatory potential, as measured by their ability to cause colitis in vivo. Resting T cells are quiescent, whereas activated T cells have high metabolic demands. Fulfillment of these metabolic demands depends upon nutrient availability and upregulation of nutrient intake channels after efficient TCR signal transduction, which leads to metabolic reprogramming in T cells. We tested whether defects in effector functions were caused by impaired metabolic shifts in Themis-deficient CD4+ T cells due to inefficient TCR signal transduction, in turn caused by the lack of Themis. We found that upon TCR stimulation, Themis-deficient CD4+ T cells were unable to upregulate the expression of insulin receptor (IR), glucose transporter (GLUT1), the neutral amino acid transporter CD98 and the mTOR pathway, as measured by c-Myc and pS6 expression. Mitochondrial analysis of activated Themis-deficient CD4+ T cells showed more oxidative phosphorylation (OXPHOS) than aerobic glycolysis, indicating defective metabolic reprogramming. Furthermore, we found reduced NFAT translocation in Themis-deficient CD4+ T cells upon TCR stimulation. Using previously reported ChIP-seq and RNA-seq data, we found that NFAT nuclear translocation controls IR gene expression. Together, our results describe an internal circuit between TCR signal transduction, NFAT nuclear translocation, and metabolic signaling in CD4+ T cells.

Calculated determination of the flow coefficient through the intake system of the internal combustion engine

Taking into account the complexity and duration of creating the optimal shape of the flow part of the intake system, it is advisable to use mathematical models in its design and modernization. This not only reduces the cost and speeds up the creation of an optimal air path, but also provides conditions for automating the design process. The calculated determination of the flow coefficient using modern methods allows you to significantly reduce the amount of experimental research and solve the main problems by choosing the optimal combination of structural elements of the intake channels at the design and finishing stage of the engine. A method is proposed for calculating the flow rate through the intake system of an internal combustion engine (ICE) depending on the design features of the intake system elements: the flow resistance coefficient, the average speed of the piston, the cross-section area of the cylinder, the average effective flow of the valve slot, the number of valves, the value of the valve lift, the diameter of the neck. The influence of total losses from gas dynamic resistance is estimated.

Selective withdrawal from an intake channel connected to a reservoir

This paper investigates selective withdrawal from an intake channel connected to a two-layer stratified reservoir using a line sink located at the downstream end of the intake channel. Such a withdrawal scenario is commonly observed at intake channels, skimming operations, and pump intake bays. This study formulates mathematical expressions for such a withdrawal scenario in order to extend our knowledge and to develop a mathematically simpler method in the case where a solution already exists. An expression to compute the incipient Froude number was developed considering the effect of a boundary. Expressions were developed to obtain discharge ratios for the scenarios when the line sink is located at the channel bottom and far away from the channel bottom. When the interface is located below the channel bottom and only at the reservoir, the intake channel itself behaves as a rectangular orifice, and an expression to compute the incipient Froude number for such a case was developed. The mathematical results were compared to the results obtained from a computational fluid dynamics solver and other relevant published studies.

Seismic Analysis of Inlet and Outlet of Water Intake Channel

Aiming at the nuclear power plant structure of Haiyang Shandong and adopting time domain analysis approach, the seismic analysis of inlet and outlet parts of water intake channel are made in this paper. The changes of internal force of the inlet and outlet parts of the water intake channels under the complicated muti-load environment of soil pressure, temperature, water hammer pressure, seismic load is analyzed. The calculation results show that the water hammer pressure, the seismic load and wall thickness of the wall have a significant effect, and encrypted reinforcement at the weak section should be applied during the design and construction. The calculation can provide the basis for the seismic analysis of the water intake channel in nuclear power plant.

Role of the intake generated thermal stratification on the temperature distribution at top dead center of the compression stroke

This work investigates the role of the intake generated thermal stratification in the temperature field evolution during the compression stroke using direct numerical simulation. The analysis compares two direct numerical simulations during the compression stroke, from which one is initialized with a homogeneous temperature distribution and the other one with a stratified temperature field resulting from a precursor direct numerical simulation of the intake stroke. All other initial and boundary conditions are identically imposed. The results show that the thermal situation at bottom dead center has nearly no impact on the evolution of the temperature field and the wall heat transfer during compression. Dominating mechanism for the temperature field evolution is found to be the convective transport of cold gases from the boundary layers toward the cylinder center. As a consequence, the wall temperature and the flow field are the main influencing parameters controlling the evolution of the temperature distribution during compression. This finding can assist practical engine experiments, since it points out which mechanisms are promising to affect the temperature field during the compression stroke. In addition, it explains why the stratification of the temperature field during intake by varying the gas temperatures in the two intake channels showed only a minor impact on the thermal situation at top dead center.

Determination of appropriate dimensions of submerged vanes

Utilisation of submerged vanes in front of intake ports is an effective approach to address sedimentation in lateral intakes from rivers. Strategically installed, these flow-training structures could increase the mid-depth and near surface flows into the intake, and simultaneously prevent bed-load transport from entering the intake channels. The effectiveness of submerged vanes depends on their number, shape, dimensions and configuration. Determination of optimum values for dimensions or configuration of the vanes is very challenging as the effect of many parameters, which are effective in sedimentation in the intake zone, must be investigated. In this study, effort has been made to determine appropriate dimensions of submerged vanes that are installed in front of a 90° intake from a straight channel. Fuzzy TOPSIS, a multi-objective optimisation method, has been utilised for the optimisation process by considering ten parameters. The simulations have been conducted for three discharge ratios of 0·11, 0·16 and 0·21. The results show that a height of 0·2 times the flow depth, and a length of four times the vane height are the appropriate dimensions for utilisation of submerged vanes in front of the lateral intakes from straight channels.

Thermal analysis and two-directional air flow thermal management for lithium-ion battery pack

Thermal management is a routine but crucial strategy to ensure thermal stability and long-term durability of the lithium-ion batteries. An air-flow-integrated thermal management system is designed in the present study to dissipate heat generation and uniformize the distribution of temperature in the lithium-ion batteries. The system contains of two types of air ducts with independent intake channels and fans. One is to cool the batteries through the regular channel, and the other minimizes the heat accumulations in the middle pack of batteries through jet cooling. A three-dimensional anisotropic heat transfer model is developed to describe the thermal behavior of the lithium-ion batteries with the integration of heat generation theory, and validated through both simulations and experiments. Moreover, the simulations and experiments show that the maximum temperature can be decreased to 33.1 °C through the new thermal management system in comparison with 42.3 °C through the traditional ones, and temperature uniformity of the lithium-ion battery packs is enhanced, significantly.

Structural Engineering Challenges in Structures for Cooling Water System in Thermal Power Plant

Abstract Water is one of the most important resource requirements in thermal power plant for process cooling in the condenser, ash disposal, cooling of plant auxiliaries and various other plant consumptive uses. Cooling water requirement in a thermal power plant is a major water resource issue for project feasibility as it has tremendous effect on the surrounding environment, population, animal and aquatic life. In a thermal power plant, Cooling Water system is one of the most important power plant systems which ensure continuous supply of cooling water for steam condensation in condenser and other plant equipment. Power plants are key elements of national infrastructure and eco-friendly solutions are required for commitment to the society. With a thrust on use of non-agricultural land as well as potential for importing coal through sea, the power plants are now being developed along the coastal lines, where water is available in abundance. The cooling process can be done either through air or with use of water and both have its merits and demerits. With increased power demand, the sizes of power plant units have increased substantially as compared with previous decades. This has further called for large structures and has imposed many engineering challenges for a power plant engineer. From civil and structural engineering perspective, the CW system involves very large water conveying and retaining structures namely cooling towers, intake and discharge channels, forebay, large underground sump, pump station for housing of large cooling water pumps, large piping between cooling tower and condenser, etc. In order to reduce the capital and running cost of the plant, thrust on economical design is emphasized. This imposes an additional constraint for engineer and it demands meticulous analysis and design to provide optimum techno-commercial solution. The present study describes various types of CW systems, structures and associated engineering challenges faced by structural engineer.

Experimental effect of flow depth on ratio discharge in lateral intakes in river bend

Open-channel dividing flow is characterized by the inflow and outflow discharges, the upstream and downstream water depths, and the recirculation flow in the branch channel. In general, diversion flow can be categorized as natural and artificial flow. Natural flow diversion usually occurs as braiding or cut-off in bend rivers, while artificial flow is man-made to divert flow by lateral intake channels for water supply. This study presents the results of a laboratory research into effect intake flow depth on ratio discharge in lateral intakes in 180 degree bend. Investigation on lateral intake and determination of intake flow depth is among the most important issues in lateral intake on ratio discharge with model intake flow depth were measured in a laboratory flume under clear-water. Experiments were conducted for various intake flow depths and with different discharges. It was found that by increasing the flow depth at 180 degree flume bend, ratio discharge increases.

Моделирование газодинамических потоков в каналах сверхзвуковых воздухозаборников на основе модели трехмерного пограничного слоя

Моделирование газодинамических потоков в каналах сверхзвуковых воздухозаборников на основе модели трехмерного пограничного слоя

Numerical modeling of seawater flow through the flooding system of dry docks

Numerical simulations have been carried out on the flooding system of a dry dock in design stage and to be located at the south coasts of Iran. The main goals of the present investigation are to evaluate the flooding time as well as the seawater flow characteristics in the intake channels of the dock. The time dependent upstream and downstream boundary conditions of the flooding system are imposed in the modeling. The upstream boundary condition is imposed in accordance with the tidal fluctuations of sea water level. At the downstream, the gradually rising water surface elevation in the dry dock is described in a transient boundary condition. The numerical results are compared with available laboratory measured data and a good agreement is obtained. The seawater discharge through the flooding system and the required time to filling up the dry dock is determined at the worst case. The water current velocity and pressure on the rigid boundaries are also calculated and discussed.

Construction de l'évacuateur de crues Opinaca

The Opinaca spillway is one of the concrete structures of the EOL (Eastmain – Opinaca – La Grande) project within the "La Grande" hydroelectric complex at James Bay, Quebec. Three rivers were diverted to the La Grande River to increase the hydroelectric potential of the LG 2 power plant. Opinaca spillway is a reinforced concrete structure 28.7 m wide and 46.6 m long with intake and restitution channels excavated in the rock. This paper describes the different construction phases of the spillway with emphasis on rock excavation and support, grouting, concreting, and quality control. Key words: blasting, bolting, concreting, dowel, excavation, grouting, presplitting, rock, shotcrete, spillway.