Determination of Nonlinear Aerodynamic Coefficients using the Estimation-Before-Modeling Methods

A numerical study of the survivability of the flange assembly is carried out upon reaching a critical load and in the presence of a defect in one of the design areas, taking into account the calculated values of the aerodynamic coefficients. An experiment is being carried out to determine the values of the wind load acting on the supporting legs of a metal tower. The calculation of the stressstrain state is performed using software system as SCAD Office and IDEA StatiCa 10.0. After calculating the forces in the core model of the structure, a threedimensional plate model of the assembly is formed and prepared for calculation. According to the results of the experiment, a graph was compiled with the values of aerodynamic coefficients, which were used in calculating the stressstrain state of the node. The analysis of the calculation results revealed that in the design (defectfree) state of the structure, the safety factor of the bearing units and elements is 35-40% (equivalent stresses were 165 MPa). If there is a defect in the metal structures of the belt in the region of the flange, the equivalent stresses increase to 247.6 MPa in the region of the cleavage (defective hole), thus, the margin in bearing capacity drops to 0.4%. As a result of the assessment of the survivability of the flange connection, it was revealed that the connection has a high potential survivability, in turn, the flange itself is able to work in the presence of some defects without reducing its bearing capacity to a critical level. The aerodynamic coefficients obtained in this work will determine the wind load on this type of profile and can be used in design calculations of tower structures for wind loads.

Download Full-text

Experience in Optimizing the Location and Parameters of Multistage Hydraulic Fractures for a Multilateral Well Based on Reservoir Simulation

10.2118/206541-ms ◽

2021 ◽

Author(s):

Vil Syrtlanov ◽

Yury Golovatskiy ◽

Konstantin Chistikov ◽

Dmitriy Bormashov

Keyword(s):

Hydraulic Fracturing ◽

Reservoir Simulation ◽

Optimal Placement ◽

Hydraulic Fractures ◽

Low Permeability ◽

Advantages And Disadvantages ◽

Modeling Methods ◽

Multistage Hydraulic Fracturing ◽

Determination Of Parameters

Abstract This work presents the approaches used for the optimal placement and determination of parameters of hydraulic fractures in horizontal and multilateral wells in a low-permeability reservoir using various methods, including 3D modeling. The results of the production rate of a multilateral dualwellbore well are analyzed after the actual hydraulic fracturing performed on the basis of calculations. The advantages and disadvantages of modeling methods are evaluated, recommendations are given to improve the reliability of calculations for models with hydraulic fracturing (HF)/ multistage hydraulic fracturing (MHF).

Download Full-text

Determination of nonlinear aerodynamic characteristics from trajectory data of an object: Modification of the method for complicated cases

Technical Physics ◽

10.1134/1.1259046 ◽

1998 ◽

Vol 43 (6) ◽

pp. 644-647

Author(s):

A. B. Podlaskin

Keyword(s):

Aerodynamic Characteristics ◽

Trajectory Data ◽

Nonlinear Aerodynamic

Download Full-text

Advances in Structure Modeling Methods for Cryo-Electron Microscopy Maps

Molecules ◽

10.3390/molecules25010082 ◽

2019 ◽

Vol 25 (1) ◽

pp. 82 ◽

Cited By ~ 2

Author(s):

Eman Alnabati ◽

Daisuke Kihara

Keyword(s):

Electron Microscopy ◽

De Novo ◽

Molecular Structures ◽

Structure Modeling ◽

Rapid Progress ◽

Macromolecular Complexes ◽

Modeling Methods ◽

Cryo Electron Microscopy ◽

Density Maps

Cryo-electron microscopy (cryo-EM) has now become a widely used technique for structure determination of macromolecular complexes. For modeling molecular structures from density maps of different resolutions, many algorithms have been developed. These algorithms can be categorized into rigid fitting, flexible fitting, and de novo modeling methods. It is also observed that machine learning (ML) techniques have been increasingly applied following the rapid progress of the ML field. Here, we review these different categories of macromolecule structure modeling methods and discuss their advances over time.

Download Full-text