scholarly journals Geodynamic Hazard Factors of Latvia: Experimental Data and Computational Analysis

2019 ◽  
Vol 7 (1) ◽  
Author(s):  
Valērijs Ņikuļins
Keyword(s):  
Experimental Data ◽  
Computational Analysis

Two-Phase Flow Behavior in Channels With Sudden Area Change Using Experimental and Computational Approach

2017 ◽  
Author(s):  
Ashish Kotwal ◽  
Che-Hao Yang ◽  
Clement Tang
Keyword(s):  
Experimental Data ◽  
Pressure Drop ◽  
Experimental Analysis ◽  
Single Phase ◽  
Computational Analysis ◽  
Phase Flow ◽  
Single Phase Flow ◽  
Two Phase ◽  
Flow Rates ◽  
Area Change

The current study shows computational and experimental analysis of multiphase flows (gas-liquid two-phase flow) in channels with sudden area change. Four test sections used for sudden contraction and expansion of area in experiments and computational analysis. These are 0.5–0.375, 0.5–0.315, 0.5–0.19, 0.5–0.14, inversely true for expansion channels. Liquid Flow rates ranging from 0.005 kg/s to 0.03 kg/s employed, while gas flow rates ranging from 0.00049 kg/s to 0.029 kg/s implemented. First, single-phase flow consists of only water, and second two-phase Nitrogen-Water mixture flow analyzed experimentally and computationally. For Single-phase flow, two mathematical models used for comparison: the two transport equations k-epsilon turbulence model (K-Epsilon), and the five transport equations Reynolds stress turbulence interaction model (RSM). A Eulerian-Eulerian multiphase approach and the RSM mathematical model developed for two-phase gas-liquid flows based on current experimental data. As area changes, the pressure drop observed, which is directly proportional to the Reynolds number. The computational analysis can show precise prediction and a good agreement with experimental data when area ratio and pressure differences are smaller for laminar and turbulent flows in circular geometries. During two-phase flows, the pressure drop generated shows reasonable dependence on void fraction parameter, regardless of numerical analysis and experimental analysis.

Three Dimensional Heat Transfer Analysis of High Pressure Turbine Blade

2009 ◽  
Author(s):  
A. Sipatov ◽  
L. Gomzikov ◽  
V. Latyshev ◽  
N. Gladysheva
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
High Pressure ◽  
Rotor Blade ◽  
Computational Analysis ◽  
Three Dimensional ◽  
Heat Transfer Analysis ◽  
Aircraft Engines ◽  
Turbine Stage ◽  
High Pressure Turbine

The present tendency of creating new aircraft engines with a higher level of fuel efficiency leads to the necessity to increase gas temperature at a high pressure turbine (HPT) inlet. To design such type of engines, the improvement of accuracy of the computational analysis is required. According to this the numerical analysis methods are constantly developing worldwide. The leading firms in designing aircraft engines carry out investigations in this field. However, this problem has not been resolved completely yet because there are many different factors affecting HPT blade heat conditions. In addition in some cases the numerical methods and approaches require tuning (for example to predict laminar-turbulent transition region or to describe the interaction of boundary layer and shock wave). In this work our advanced approach of blade heat condition numerical estimation based on the three-dimensional computational analysis is presented. The object of investigation is an advanced aircraft engine HPT first stage blade. The given analysis consists of two interrelated parts. The first part is a stator-rotor interaction modeling of the investigated turbine stage (unsteady approach). Solving this task we devoted much attention to modeling unsteady effects of stator-rotor interaction and to describing an influence of applied inlet boundary conditions on the blade heat conditions. In particular, to determine the total pressure, flow angle and total temperature distributions at the stage inlet we performed a numerical modeling of the combustor chamber of the investigated engine. The second part is a flow modeling in the turbine stage using flow parameters averaging on the stator-rotor interface (steady approach). Here we used sufficiently finer grid discretization to model all perforation holes on the stator vane and rotor blade, endwalls films in detail and to apply conjugate heat transfer approach for the rotor blade. Final results were obtained applying the results of steady and unsteady approaches. Experimental data of the investigated blade heat conditions are presented in the paper. These data were obtained during full size experimental testing the core of the engine and were collected using two different type of experimental equipment: thermocouples and thermo-crystals. The comparison of experimental data and final results meets the requirements of our investigation.

scholarly journals ANALYSIS OF NONLINEAR STATIC-DYNAMIC DEFORMATION OF REINFORCED CONCRETE FRAMES IN OUT-OF-LIMIT STATES

2021 ◽  
pp. 20-35
Author(s):  
N. V. Fedorova ◽  
Ngoc Tuyen Vu ◽  
M. D. Medyankin
Keyword(s):  
Experimental Data ◽  
Reinforced Concrete ◽  
Dynamic Loading ◽  
Computational Analysis ◽  
Dynamic Deformation ◽  
Limit State ◽  
Concrete Frames ◽  
Limit States ◽  
Reinforced Concrete Frames ◽  
Nonlinear Static

Statement of the problem. The article presents a computational model, an algorithm for computational analysis and the results of calculating the nonlinear static-dynamic deformation of reinforced concrete frames in out-of-limit states caused by the sudden removal of one of the supporting structures. Results. To design a numerical model of the static-dynamic loading mode of a structural system, the LS-DYNA software package was used that makes use of a detailed 3D model implementing an explicit finite element method. During the computational analysis, the physical and mechanical characteristics of the deformation of materials were taken in three variants: those obtained based on the experimental data by G. A. Geniev, the experimental data by N. V. Fedorova and M. D. Medyankin under the static-dynamic uniaxial testing mode of a limited number of standard samples of prisms and according to the Russian standards SP (СП) 385.1325800.2018. Conclusions. Numerical analysis of the static-dynamic deformation of the reinforced concrete framerod system of a multi-storey building has established that the differentiated accounting of the quantitative value of the concrete viscosity modulus and, accordingly, the time and level of static-dynamic loading of the structure allows one to identify the criteria for the special limit state of the elements of reinforced concrete structural systems of buildings and structures in a more rigid manner.

scholarly journals Application of classical numerical methods in the calculation of solidification modes of a continuous ingot

2020 ◽  
pp. 41-47
Author(s):  
V. I. Timoshpolsky ◽  
E. I. Marukovich ◽  
I. A. Trusova
Keyword(s):  
Experimental Data ◽  
Finite Element Method ◽  
Finite Element ◽  
Numerical Methods ◽  
Continuous Casting ◽  
Computational Analysis ◽  
The Finite Element Method ◽  
Casting Technology ◽  
Continuous Ingot ◽  
Continuously Cast

This paper presents approaches to the computational analysis of solidification and cooling processes of continuously cast billets in order to improve and develop technological modes in the conditions of modern continuous casting machines using FEM.The application of modern numerical methods for solidification and cooling of workpieces on continuous casting machines is considered. The use of the finite element method is justified when using computational and experimental data for the development and improvement of casting technology.

Computational Analysis of Performance of Smoke Exhaust System in Atrium Buildings with Nonuniform Spaces

2011 ◽  
Vol 250-253 ◽  
pp. 2993-2997
Author(s):  
Jun Mei Li ◽  
Yan Feng Li ◽  
Jing Sui ◽  
Shan Shan Liu ◽  
Xin Wang
Keyword(s):  
Fluid Dynamics ◽  
Experimental Data ◽  
Research Laboratory ◽  
Computational Analysis ◽  
Field Model ◽  
Exhaust System ◽  
Zone Model ◽  
Fire Models ◽  
Smoke Test ◽  
Analysis Of Performance

Performance of the smoke exhaust system in two atria with nonuniform spaces will be analyzed by fire models in this paper. A two-layer zone model and a Computational Fluid Dynamics field model FDS developed by the Building and Fire Research Laboratory, National Institute of Standards and Technology, USA are used. Numerical results are compared with the experimental data by hot smoke test in these two atria. Both fire models can give good predictions and so are suitable for evaluating the performance of the smoke exhaust system.

scholarly journals Assessment of IsPETase-Assisted Depolymerization of Terephthalate Aromatic Polyesters and the Effect of the Thioredoxin Fusion Domain

2021 ◽  
Vol 11 (18) ◽  
pp. 8315
Author(s):  
Paula Wagner-Egea ◽  
Virginia Tosi ◽  
Ping Wang ◽  
Carl Grey ◽  
Baozhong Zhang ◽  
...  
Keyword(s):  
Experimental Data ◽  
Ethylene Terephthalate ◽  
Computational Analysis ◽  
Butylene Terephthalate ◽  
Environmental Threat ◽  
Poly Ethylene Terephthalate ◽  
Fusion Domain ◽  
Poly Ethylene ◽  
Socioeconomic Benefits

Terephthalate polyesters such as poly(ethylene terephthalate) (PET) have been massively produced over the last few decades due to their attractive properties in multiple applications. However, due to their limited biodegradability, they have accumulated in landfills and oceans, posing an environmental threat. Enzymatic recycling technologies are predicted to generate long-term socioeconomic benefits. In the present work, we compared the IsPETase (from Ideonella sakaiensis 201-F6) activity on a series of polyesters, including poly(butylene) terephthalate (PBT), poly(hexamethylene) terephthalate (PHT) and Akestra™, with PET. The IsPETase showed remarkable activity toward PET (39% degradation of the original polyester) that was higher than that toward Akestra™ (0.13%), PBT (0.25%) and PHT (0.13%) after 72 h. Thus, based on experimental data and computational analysis, we report insights into IsPETase activity on a series of terephthalate-based polyesters. Aside from that, the fusion domain (Trx) effect in the production and activity of a recombinant Trx-IsPETase is reported.

scholarly journals Minimization of excess torque in multi-time deployment-folding hinge joints

2021 ◽  
Vol 5 (1) ◽  
pp. 35-43
Author(s):  
S. A. Zommer ◽  
S. I. Nemchaninov ◽  
A. P. Kravchunovsky ◽  
A. V. Ivanov ◽  
M. S. Rudenko
Keyword(s):  
Experimental Data ◽  
Computational Analysis ◽  
Mechanical Characteristics ◽  
Solar Array ◽  
Constant Force ◽  
Calculation Algorithm ◽  
Drive Force ◽  
Design Algorithms ◽  
Mechanical Devices ◽  
Angle Of Rotation

The paper presents a method for minimizing the torque value of the multi-time deploymentfolding hinges. The objects of research were the hinges assembly of multi-time deployment-folding mechanical devices of solar array, which are used as part of the platforms of spacecraft. A computational analysis of the forces and moments that act in the hinges in the process of their opening and folding is carried out. The minimization of the excessive torque value without changing the design and layout of the hinge is possible by changing the shape of the dependence of the spring drive force on the angle of rotation of the hinge. The possibility of using constant force springs as part of the hinge is considered, the existing design algorithms are improved and a program for calculating the geometric and mechanical characteristics of constant force springs is developed. Experimental data were obtained for measuring the forces of springs of various configurations, showing the dependence of the magnitude of the force on the magnitude of the spring deformation and confirming the efficiency of the proposed calculation algorithm. A prototype of a hinge assembly with a constant force spring drive was developed and manufactured. The possibility of minimizing the excess torque without the need to change the design of the hinge while maintaining its technical characteristics was experimentally confirmed.

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