scholarly journals Developing the Flow Path For the K-1250-6.9/25 Turbine Unit Using the Optimal Design Methods

2021 ◽  
pp. 15-18
Author(s):  
Ihor Palkov ◽  
Sergii Palkov ◽  
Oleh Ishchenko ◽  
Olena Avdieieva
Keyword(s):  
Numerical Experiment ◽  
Cross Sections ◽  
Turbine Unit ◽  
Current Flow ◽  
Three Dimensional ◽  
Flow Path ◽  
Three Dimensional Model ◽  
Flow Paths ◽  
Intermediate Pressure ◽  
Blade System

The paper considers the main principles that are used to develop the flow paths (FP) of the high-pressure cylinders (HPC), intermediate-pressure cylinders (IPC), and low-pressure cylinders (LPC) for the K-1250-6.9/25 turbine unit. It describes approaches to the numerical experiment when designing flow paths, the advantage of which is lower labor, time and financial costs and higher informativeness compared to the physical experiment on flow paths. When designing the flow paths of high- and intermediate-pressure cylinders (HIPC), the numerical experiment is performed using the three-dimensional viscous-flow method. For this purpose, a three-dimensional model of the blade system in the flow path is built, which consists of a large number of finite volumes (elements) in the shape of hexagons, in each of which the integration of the equations of gas dynamics is performed. When developing LPC, the method of parameterization and analytical profiling of the blade crown sections is used, where the profiles are described by the curves of the fourth and fifth orders with the condition of providing the minimum value of the maximum curvature and monotonicity of variation of the three-dimensional blade geometry along height. This method allows obtaining the optimal profiles of the cross sections of the blades, which correspond to the current flow lines to the fullest extent, and minimizing the profile energy losses when the flow flows around the blades.

Application of Bentley Power Rail Track Software in the BIM Railway Design

2014 ◽  
Vol 587-589 ◽  
pp. 1091-1094
Author(s):  
Xi Sheng ◽  
Hua Peng Luo ◽  
Ping Wang
Keyword(s):  
Cross Sections ◽  
High Efficiency ◽  
Three Dimensional ◽  
Digital Terrain Model ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Rail Track ◽  
Terrain Model ◽  
Digital Terrain ◽  
Design Software

Belonging to the Bentley Microstation series which work as one of the BIM platforms, the Bentley Power Rail Track shows huge advantages in the railway design for its visibility, high efficiency, advance, reliability and so on. This paper introduces the way to build the digital terrain model, alignments, cross sections, turnouts and to display the three-dimensional model of the railway for the Bentley Power Rail Track 3D railway design software. It provides application preparation for the BIM railway design and achieves the preliminary exploration of BIM applications. Bentley Power Rail Track proves capable of the BIM railway design.

Image processing algorithms in the assessment of grain damage degree

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Wojciech Maliga ◽  
Włodzimierz Dudziński ◽  
Magdalena Łabowska ◽  
Jerzy Detyna ◽  
Marcin Łopusiewicz ◽  
...  
Keyword(s):  
Image Processing ◽  
Cross Sections ◽  
Three Dimensional ◽  
Sample Volume ◽  
Three Dimensional Model ◽  
Time Intervals ◽  
Damage Degree ◽  
Grain Damage ◽  
Analyse Sample

Abstract Objectives The paper presents preliminary results on the assessment of algorithms used in image processing of the grain damage degree. The purpose of the work is developing a tool allowing to analyse sample cross-sections of rye germs. Methods The analysis of the grain cross-sections was carried out on the basis of a series their photos taken at equal time intervals at a set depth. The cross-sections will be used to create additional virtual cross-sections allowing to analyse the whole sample volume. The ultimate plan is to generate two cross-sections perpendicular to each other. Based on volumetric data read from the sample section, a three-dimensional model of an object will be generated. Results The analysis of model surface will allowed us to detect possible grain damage. The developed method of preparing the research material and the proprietary application allowed for the identification of internal defects in the biological material (cereal grains). Conclusions The presented methodology may be used in the agri-food industry in the future. However, much research remains to be done. These works should primarily aim at significantly reducing the time-consuming nature of individual stages, as well as improving the quality of the reconstructed image.

scholarly journals Prediction of the spatial variability of coal-bearing rocks at the Elginsky coal mine

2020 ◽  
Vol 192 ◽  
pp. 04007
Author(s):  
Yuri Malinin ◽  
Nikolai Grib ◽  
Pavel Kuznetsov ◽  
Zhang Ze
Keyword(s):  
Spatial Variability ◽  
Cross Sections ◽  
Coal Mine ◽  
Three Dimensional ◽  
Spatial Modelling ◽  
Ash Content ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Markov Modelling ◽  
Composition Structure

The article presents a brief analysis of the key methods used for spatial modelling of mining and geological indicators describing the composition, structure and state of rock deposits. The main limitations of the analysed methods when applied under real conditions are outlined. It is proposed to overcome these limitations using Markov nonlinear algorithms. By applying the principles of multi-dimensional Markov modelling to a geological object, interval types were determined for modelling mining and geological parameters of the Elginsky coal mine. As an example, the article presents the results of predicting the ash content for the U5 section of the Elginsky coal mine on the basis of one of the cross-sections of the developed three-dimensional model.

scholarly journals Analysis of the velocity diagrams of impellers of centrifugal compressor stages after the preliminary design

2018 ◽  
Vol 245 ◽  
pp. 04004 ◽  
Author(s):  
Aleksandr Drozdov ◽  
Alexey Rekstin
Keyword(s):  
Centrifugal Compressor ◽  
Three Dimensional ◽  
Flow Path ◽  
Preliminary Design ◽  
Flow Paths ◽  
Design Program ◽  
Three Stages ◽  
Correct Application ◽  
Development Laboratory

Preliminary design is an important stape in the development of centrifugal compressors and compressor stages. Basically for this purpose, various recommendations on the choice of the flow path dimensions are applied. Researchers of the Research and Development Laboratory “Gas dynamics of turbomachines” prof. Yu.B. Galerkin and A.F. Rekstin analyzed and summarized the dimensions of flow paths of 124 impellers. On the basis of this analysis, formulas were proposed for choosing the flow path dimensions of the centrifugal compressor stages, which were included in the preliminary design program. The formulas used are designed for relative Mach number of 0.7 and isentropic coefficient of 1.4. The correct application of these formulas for other Mach numbers and isentropic coefficient required development of an appropriate approach and algorithm for adjusting the height of the impeller blades at the outlet. Calculations of gas-dynamic characteristics using the Universal Modeling Method showed the need for selecting a coefficient that takes into account the influence of viscosity to obtain the required pressure characteristics of the compressor stage. This problem was also solved in the program of preliminary design. To check the quality of preliminary design, the results were verified using a non-viscous quasi-three-dimensional calculation program. Three stages were designed for parameters different to those used for development of preliminary design formulas. Analysis of the velocity diagrams of the impeller blades and distribution of meridional velocities showed good results of the preliminary design.

Thermal anomalies and geological structures in the Provence basin: Implications for hydrothermal circulations at depth

2010 ◽  
Vol 181 (4) ◽  
pp. 363-376 ◽  
Author(s):  
Cynthia Garibaldi ◽  
Laurent Guillou-Frottier ◽  
Jean-Marc Lardeaux ◽  
Damien Bonté ◽  
Simon Lopez ◽  
...  
Keyword(s):  
Cross Sections ◽  
Numerical Models ◽  
Three Dimensional ◽  
Thermal Anomaly ◽  
Three Dimensional Model ◽  
Geological Structures ◽  
Thermal Anomalies ◽  
Cold Area ◽  
Major Fault ◽  
Deep Temperature

Abstract Deep temperature estimates previously made in France show three main positive thermal anomalies, one of them being centred on the Provence basin (southeast France) between Marseille and Montpellier. This study presents newly corrected temperature data and improved temperature maps in order to (i) validate or to invalidate the thermal anomalies previously identified and (ii) relate deep temperatures with major geological structures of the area. Although the thermal gradient varies from place to place, it averages 31.3°C./km in the Provence basin (from 30.6 to 32.5°C/km in average for France according to the chosen database), but some locations show gradients reaching 36°C/km. To characterize thermal anomalous areas, a three-dimensional model of the temperatures was built between the surface and 6 km depth, allowing us to elaborate thermal maps and cross-sections. The identified thermal anomalies are different from those obtained by former works. New other "hot" anomalous areas (Montpellier, Lodève and Drôme areas) and cold anomalous areas (Aix-en-Provence and Cévennes areas) have been highlighted. At depth, thermal cross-sections show 50 km-scale anomalies, which are parallel with the major faults (Cévennes, Nimes, Salon-Cavaillon and Moyenne-Durance faults) whereas more elongated (roughly 100 km) anomalies are associated with perpendicular cross-sections. On these cross-sections each major fault is associated with a thermal anomaly. In addition, a cold area may overlie a warm one, and vice versa. Among different possible explanations, these thermal signatures could correspond to convective fluid circulation within the faults. Simple numerical models of hydrothermal convection within fault zones appear to reproduce similar amplitudes and vertical variations of thermal anomalies as those observed in the Provence basin.

Fractal analysis and imaging of the proximal nephron cell

1996 ◽  
Vol 270 (3) ◽  
pp. C953-C963 ◽  
Author(s):  
D. Welling ◽  
J. Urani ◽  
L. Welling ◽  
E. Wagner
Keyword(s):  
Fractal Dimension ◽  
Cross Sections ◽  
Three Dimensional ◽  
Fractal Dimensions ◽  
Cell Periphery ◽  
Proximal Tubule Cell ◽  
Three Dimensional Model ◽  
Cell Height ◽  
Fractal Patterns ◽  
Cell Base

Cells of the S1 proximal renal tubule were examined to determine whether their peculiar shapes are a result of certain constructs of fractal mathematics. Morphometric measurements of the cell perimeter were made at several levels of cell height by measuring the intercellular boundaries that appear on electron micrographs of tubule cross sections. When the measurements were made over a range of scale lengths, the fractal dimension, D, of the cell perimeter was found to increase from 1.3 near the cell apex to 1.78 near the cell base. The length of scale was found to range between 8 and 0.4 micron and to represent the approximate dimensions of actual cell processes. Fractal patterns that conformed to the measured parameters were then constructed from a fractal generator composed of budlike formations that originated near the cell apex and that increased in number and decreased in size with cell depth according to a fractal scaling. It was found that the fractal rule of keeping a constant relative scale could be maintained between budding processes but, to obtain patterns that resemble biological structure, the processes must be positioned randomly on the cell periphery. It is shown that when the relative sizes of the buds decrease exponentially and their numbers increase geometrically, the perimeter can grow to the correct length without overlap. This suggests that patterns of the cell periphery corresponding to different levels of cell height obey a law of scale but occur randomly in a way that increases to high fractal dimension or near plane-filling values at the cell base. The fractal patterns that correspond to the measured fractal dimensions can be assembled into a three-dimensional model that closely resembles the known shape of the proximal tubule cell.

scholarly journals UAVS TO ASSESS THE EVOLUTION OF EMBRYO DUNES

2017 ◽  
Vol XLII-2/W6 ◽  
pp. 363-369 ◽  
Author(s):  
Y. Taddia ◽  
C. Corbau ◽  
E. Zambello ◽  
V. Russo ◽  
U. Simeoni ◽  
...  
Keyword(s):  
Cross Sections ◽  
Low Cost ◽  
Three Dimensional ◽  
Point Clouds ◽  
Coastal Environment ◽  
Three Dimensional Model ◽  
Dune System ◽  
Continuous Formation ◽  
Digital Elevation ◽  
Gnss Receivers

The balance of a coastal environment is particularly complex: the continuous formation of dunes, their destruction as a result of violent storms, the growth of vegetation and the consequent growth of the dunes themselves are phenomena that significantly affect this balance. This work presents an approach to the long-term monitoring of a complex dune system by means of Unmanned Aerial Vehicles (UAVs). Four different surveys were carried out between November 2015 and November 2016. Aerial photogrammetric data were acquired during flights by a DJI Phantom 2 and a DJI Phantom 3 with cameras in a nadiral arrangement. GNSS receivers in Network Real Time Kinematic (NRTK) mode were used to frame models in the European Terrestrial Reference System. Processing of the captured images consisted in reconstruction of a three-dimensional model using the principles of Structure from Motion (SfM). Particular care was necessary due to the vegetation: filtering of the dense cloud, mainly based on slope detection, was performed to minimize this issue. Final products of the SfM approach were represented by Digital Elevation Models (DEMs) of the sandy coastal environment. Each model was validated by comparison through specially surveyed points. Other analyses were also performed, such as cross sections and computing elevation variations over time. The use of digital photogrammetry by UAVs is particularly reliable: fast acquisition of the images, reconstruction of high-density point clouds, high resolution of final elevation models, as well as flexibility, low cost and accuracy comparable with other available techniques.

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