The Stability Analysis of Heituwan Tailings Pond Based on Strength Reduction Method

To analyze the stability of Heituwan tailings pond after vacuum well point dewatering treatment, a unit thickness numerical 3D model was built based on field survey data and physical mechanical properties tests; and the model was analyzed by FEM numerical software according to strength reduction method. The properties of stress and strain, the plastic region, and the deformation properties are acquired by numerical stimulation, and the simulation result was compared withe the in-situ monitoring data. The results show that the safety factor does not meet the requirements of the standard; and most of the landfill made of manganese tailing has developed into plastic status; the deformation is more obvious where the tailing store is higher and closer to roller compacted rockfill dam; the manganese tailing landfill near the roller compacted rockfill dam should be grouted by cement to meet the requirements of continued use.

DETERMINING THE EFFECT OF NOZZLE GROOVE ON THE FLUID FLOW THROUGH VISCOUS 2D PLANAR FLUID

The study aims to determine the effect of nozzle groove on fluid flow through viscous 2D planar fluid. To fulfil the study’s aim, numerical method was adopted to introduce grooves of different dimensions from the nozzle exit. The study adopts SoldWork software was used to design nozzles and introduce groove shaped nozzles, each consisting of six different designs. The nozzle base model used in this study was similar to the one used in a previous study. The procedure was performed with different pressures (8, 10, and 12 bar) at the similar firefighting nozzle. The velocities contours were predicted based on the choice of nozzle section during the numerical stimulation. The results of present study demonstrated a new approach that can be used for increasing velocity at various types of modified nozzles through grooves at different pressures and locations. For grooves, dimensions 1×1 (mm) and location 15 mm at 8 bar, 10 bar and 12 bars showed no effect on velocity as it reduces velocity by increasing surface area. The velocity increases with increasing pressure in proportion relationship. This clearly explains that the groove has no effect on velocity as it increases due to increase in pressure. This is because the groove reduces the velocity by increasing surface area. The study concludes that use of groove increases velocity of water that further improves nozzles operation.

Design of a 94 GHz Millimeter-Wave Four-Way Power Combiner Based on Circular Waveguide Structure

This paper introduces a four-way power combiner operating in the 94 GHz millimeter-wave based on spatial power combining technology. The four millimeter-waves with Gaussian beams are combined in the waveguide, increasing the output power. The combiner is composed of five circular waveguides connected by four long and narrow coupling slots. Four sub-waveguides are separately connected to four input ports and one main waveguide is connected to a common output port. The TE11-mode is used as the input mode, which has two vertical and horizontal polarization directions. Four sub-waveguides are respectively input corresponding to polarization directions TE11-wave with Gaussian beams. The power of TE11-wave is transmitted to the main waveguide by the coupling slots, combined in the main waveguide, and output with the common port. We analyze the combiner and verify the availability of the design structure by numerical stimulation with CST MWS (Microwave Studio) software. The power-combining efficiency can be over 97%, and the output beams remain Gaussian beams with nearly fourfold increased power. The proposed model provides technological approaches for power combiner application in millimeter-wave.

A Multimodal Stimulation Cell Culture Bioreactor for Tissue Engineering: A Numerical Modelling Approach

The use of digital twins in tissue engineering (TE) applications is of paramount importance to reduce the number of in vitro and in vivo tests. To pursue this aim, a novel multimodal bioreactor is developed, combining 3D design with numerical stimulation. This approach will facilitate the reproducibility between studies and the platforms optimisation (physical and digital) to enhance TE. The new bioreactor was specifically designed to be additive manufactured, which could not be reproduced with conventional techniques. Specifically, the design suggested allows the application of dual stimulation (electrical and mechanical) of a scaffold cell culture. For the selection of the most appropriate material for bioreactor manufacturing several materials were assessed for their cytotoxicity. Numerical modelling methods were then applied to the new bioreactor using one of the most appropriate material (Polyethylene Terephthalate Glycol-modified (PETG)) to find the optimal stimulation input parameters for bone TE based on two reported in vitro studies.

Effect on Chest Deformation of Simultaneous Correction of Pectus Excavatum with Scoliosis

Objective. This paper is to understand the effect of simultaneous correction of pectus excavatum with scoliosis and to provide some useful information for clinical orthopedic surgery design. Methods. The method of a three-dimensional reconstruction has been used to the reconstruction of the chest model of pectus excavatum with scoliosis, and the numerical stimulation has been conducted to the process of minimally invasive correction. Three kinds of correction methods have been considered in the numerical simulation, stretch spine, stretch spine and minimally invasive correction at the same time, and release stretch spine after stretch spine and minimally invasive correction of pectus excavatum at the same time. Results. It is found that stretch spine may help to correction of scoliosis but aggravate the sternum collapse, and release stretch spine after stretch spine and minimally invasive correction at the same time could not only be good at scoliosis but also improve the collapse of the sternum, which could help to improve the heartbeat and breath of the patients. Conclusion. Among the three kinds of correction methods, release stretch spine after stretch spine and minimally invasive correction at the same time could help to improve both the scoliosis and the collapse of the sternum.

River Flow Characteristics Numerical Simulation

Divergence river which tributary and mainstream converge is one normal type of river. Study on divergence river flow characteristics has significant meaning both on academic and practical of river protection. Numerical stimulation is a effective method to study divergence river. Using intersection area’s orthogonal generalized model, analyze flow ratio of tributary and mainstream can show the influence of converge point’ position and strength. Numerical stimulation shows mainstream’s downstream of divergence river exist high-velocity flow on both side; right side’s velocity peek is larger than left side. Under the same condition, when the flow ratio bigger then right side’s velocity peek larger and the same time left side’s smaller. Velocity peek is largest when tributary flowing only and is smallest when mainstream flowing only. The result suggest that divergence river downstream should be protected and the best condition is mainstream flowing only.

Research on Optimization of Perforated Horizontal Wells with Separated Production Scheme Based on Genetic Algorithm

Based on the separated production scheme of perforated horizontal well, the production is closely related to the number, length and location of horizontal intervals. New reservoir / wellbore coupling models were modeled which included two boundaries: closed boundary and constant pressure boundary. For these coupling models, two new optimization models were modeled, which took the production as the objective function and took the length and location of horizontal intervals as the optimization variables. Then the numerical calculation models were proposed by using the Gauss-Laguerre quadrature formula. Applying the genetic algorithm and writing the numerical stimulation software, the optimized schemes with 2 segments, 3 segments and 4 segments for planning intervals of the perforated horizontal wells were presented. By comparing the optimized schemes, we can see that the horizontal well production was not infinite increasing with the length of horizontal intervals, but only in the suitable length of horizontal intervals to maintain high production. And it is not the more segments the higher production. For the perforated horizontal well in closed reservoir, the production was the highest based on the optimized schemes with 3 segments.