Effects of Wheel-Shaft-Fluid Coupling and Local Wheel Deformations on the Global Behavior of Shaft Lines

2002 ◽  
Vol 124 (4) ◽  
pp. 953-957 ◽  
Author(s):  
D. Lornage ◽  
E. Chatelet ◽  
G. Jacquet-Richardet

Rotating parts of turbomachines are generally studied using different uncoupled approaches. For example, the dynamic behavior of shafts and wheels are considered independently and the influence of the surrounding fluid is often taken into account in an approximate way. These approaches, while often sufficiently accurate, are questionable when wheel-shaft coupling is observed or when fluid elements are strongly coupled with local structural deformations (leakage flow between wheel and casing, fluid bearings mounted on a thin-walled shaft, etc.). The approach proposed is a step toward a global model of shaft lines. The whole flexible wheel-shaft assembly and the influence of specific fluid film elements are considered in a fully three-dimensional model. In this paper, the proposed model is first presented and then applied to a simple disk-shaft assembly coupled with a fluid film clustered between the disk and a rigid casing. The finite element method is used together with a modal reduction for the structural analysis. As thin fluid films are considered, the Reynolds equation is solved using finite differences in order to obtain the pressure field. Data are transferred between structural and fluid meshes using a general method based on an interfacing grid concept. The equations governing the whole system are solved within a time-marching procedure. The results obtained show significant influence of specific three-dimensional features such as disk-shaft coupling and local disk deformations on global behavior.

Author(s):  
D. Lornage ◽  
E. Chatelet ◽  
G. Jacquet-Richardet

Rotating parts of turbomachines are generally studied using different uncoupled approaches. For example, the dynamic behavior of shafts and wheels are considered independently and the influence of the surrounding fluid is often taken into account in an approximate way. These approaches, while often sufficiently accurate, are questionable when wheel-shaft coupling is observed or when fluid elements are strongly coupled with local structural deformations (leakage flow between wheel and casing, fluid bearings mounted on a thin-walled shaft, etc.). The approach proposed is a step toward a global model of shaft lines. The whole flexible wheel-shaft assembly and the influence of specific fluid film elements are considered in a fully three-dimensional model. In this paper, the proposed model is first presented and then applied to a simple disc-shaft assembly coupled with a fluid film clustered between the disc and a rigid casing. The finite element method is used together with a modal reduction for the structural analysis. As thin fluid films are considered, the Reynolds equation is solved using finite differences in order to obtain the pressure field. Data are transferred between structural and fluid meshes using a general method based on an interfacing grid concept. The equations governing the whole system are solved within a time marching procedure. The results obtained show significant influence of specific 3D features such as disc-shaft coupling and local disc deformations on global behavior.


2004 ◽  
Vol 10 (3) ◽  
pp. 213-220 ◽  
Author(s):  
David Lornage ◽  
Georges Jacquet-Richardet

While often sufficiently accurate, approaches using rotor dynamics and bladed disc dynamics are not adapted to the study of certain important cases, i.e., when observing wheel/shaft coupling or when fluid elements are strongly coupled with local structural deformations. The approach proposed here is a step toward a global model of shaft lines. The whole flexible wheel/shaft assembly and the influence of specific fluid film elements are considered in a full threedimensional model. A modal projection associated with a grid located at the interface of the fluid and structural domains provides an efficient and adaptable coupling. The equations governing the whole system are solved within a time marching procedure which alternatively considers the equations of fluid and structure. The technique chosen is applied to two different test cases. The first is composed of a disc and a thin-walled shaft mounted on a hydrodynamic bearing. The second is intended for studying a more realistic structure composed of a shaft and a wheel coupled with a fluid film between the wheel and a casing. These applications make it possible to identify trends related to fluid effects and couplings between the flexible structural parts.


2015 ◽  
Vol 9 (1) ◽  
pp. 58-64 ◽  
Author(s):  
Kuiyang Wang ◽  
Jinhua Tang ◽  
Guoqing Li

In order to optimize the design method and improve the performance of hydraulic retarder, the numerical simulation of multi-field coupling of heat, fluid and solid is carried out to hydraulic retarder, based on the numerical computation and algorithm of heat-fluid coupling and fluid-solid coupling. The computation models of heat-fluid coupling and fluid-solid coupling of hydraulic retarder are created. The three dimensional model of hydraulic retarder is established based on CATIA software, and the whole flow passage model of hydraulic retarder is extracted on the basis of the three dimensional model established. Based on the CFD calculation and the finite element numerical simulation, the temperature field, stress field, deformation and stress state are analysised to hydraulic retarder in the state of whole filling when the rotate speed is 1600 r/min. In consideration of rotating centrifugal force, thermal stress and air exciting vibration force of blade surface, by using the sequential coupling method, the flow field characteristics of hydraulic retarder and dynamic characteristics of blade structure are analysised and researched based on multi-field coupling of heat, fluid and solid. These provide the theoretical foundation and references for parametric design of hydraulic retarder.


2019 ◽  
Vol 23 (1) ◽  
pp. 144-149
Author(s):  
Djelaili Abdelbaki ◽  
Korti Abdel Ilah Nabil

Abstract Building designers have to think about new strategies to achieve the best sustainable building designs. Well-planned passive solar heating strategies in building design may reduce a building’s energy consumption significantly. In this paper, a proposed design of the south façade of a room by integrating a hybrid solar wall and a window to passively heat a room is studied. The simulations for the three-dimensional model of BIPV Trombe wall system were carried out for December 10th, 2015. The temperature and velocity distribution of indoor air in different positions inside the room are obtained from the simulation results. The obtained results show that the temperature difference between the inlet and the outlet of the solar wall can reach 9°C. The 3D analysis of the proposed model clearly shows that the window’s thermal effect on the passive heating cannot be neglected. Meanwhile, the simulation’s daily electrical efficiency conversion and average indoor air temperature of this system can reach 18% and 28° C, respectively for maximum solar radiation of 470 W/m2.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Kamel Ettaieb ◽  
Sylvain Lavernhe ◽  
Christophe Tournier

Purpose This paper aims to propose an analytical thermal three-dimensional model that allows an efficient evaluation of the thermal effect of the laser-scanning path. During manufacturing by laser powder bed fusion (LPBF), the laser-scanning path influences the thermo-mechanical behavior of parts. Therefore, it is necessary to validate the path generation considering the thermal behavior induced by this process to improve the quality of parts. Design/methodology/approach The proposed model, based on the effect of successive thermal flashes along the scanning path, is calibrated and validated by comparison with thermal results obtained by FEM software and experimental measurements. A numerical investigation is performed to compare different scanning path strategies on the Ti6Al4V material with different stimulation parameters. Findings The simulation results confirm the effectiveness of the approach to simulate the thermal field to validate the scanning strategy. It suggests a change in the scale of simulation thanks to high-performance computing resources. Originality/value The flash-based approach is designed to ensure the quality of the simulated thermal field while minimizing the computational cost.


Author(s):  
A. B. Lachikhina ◽  
K. N. Soldatov

Visualization of analyzing multidimensional data is often required in order to improve perception and visibility. The purpose of this research is a multidimensional array of data representation. It is proposed to use a three-dimensional model as a tool. The methods used to represent an array of data with more than three dimensions are presented. The principle of constructing a multidimensional array cell is considered. An example of the constructed hypercube cell is given. The formulas for calculating the number of faces of the figure, the number of triangles that can be built through points, the number of internal triangles are obtained. The approach of visualization of aggregates is described. The use of color gradation to improve the convenience of perception of the cell in the analysis of the cube cells. It is concluded that the proposed model allows us to perceive each cell as an independent data element in the construction of charts for the analyzed indicators.


2004 ◽  
Vol 279 (44) ◽  
pp. 46172-46181 ◽  
Author(s):  
Stéphanie Voisin ◽  
Didier Rognan ◽  
Claude Gros ◽  
Tanja Ouimet

Neprilysin 2 (NEP2), a recently identified member of the M13 subfamily of metalloproteases, shares the highest degree of homology with the prototypical member of the family neprilysin. Whereas the study of thein vitroenzymatic activity of NEP2 shows that it resembles that of NEP as it cleaves the same substrates often at the same amide bonds and binds the same inhibitory compounds albeit with different potencies, its physiological role remains elusive because of the lack of selective inhibitors. To aid in the design of these novel compounds and better understand the different inhibitory patterns of NEP and NEP2, the x-ray structure of NEP was used as a template to build a model of the NEP2 active site. The results of our modeling suggest that the overall structure of NEP2 closely resembles that of NEP. The model of the active site reveals a 97% sequence identity with that of NEP with differences located within the S′2subsite of NEP2 where Ser133and Leu739replace two glycine residues in NEP. To validate the proposed model, site-directed mutagenesis was performed on a series of residues of NEP2, mutants expressed in AtT20 cells, and their ability to bind various substrates and inhibitory compounds was tested. The results confirm the involvement of the conserved Arg131and Asn567in substrate binding and catalytic activity of NEP2 and further show that the modifications in its S′2pocket, particularly the presence therein of Leu739, account for a number of differences in inhibitor binding between NEP and NEP2.


Author(s):  
D. A. Belousova ◽  
V. V. Serdakova

This paper considers the task of evaluating micro-accelerations arising due to the temperature shock of large elastic elements when a small spacecraft leaves the Earth’s shadow. In this case, a one-dimensional model of thermal conductivity is used. Its solution was obtained by the method of direct approximation with the construction of difference schemes. It is shown that the accuracy of estimating micro-accelerations is commensurate with the accuracy of solving by a three-dimensional model of thermal conductivity. The proposed model allows reducing the time to obtain estimates and significantly simplifies the task at hand. The results of the work can be used in the formation of the dynamic characteristics of a small spacecraft for technological purposes.


Author(s):  
C Chen ◽  
R Kovacevic

Friction stir welding (FSW) is a solid-state jointing technology, in which the butted plates are heated, plasticized and jointed locally by the plunged probe and shoulder moving along the joint line. The residual stresses due to the thermomechanical performance of the material and the constraint of the welded plates by the fixture are one of main concerns for this process. A prediction of the clamping force applied on the plates during FSW is expected to be helpful in controlling the residual stresses and weld quality. Furthermore, the prediction of the force history in FSW will be beneficial to understand the mechanics of the process and to provide valid models for controlling the process, especially in the case of robotic FSW. In this paper, a three-dimensional model based on a finite element method is proposed to study the thermal history and stress distribution in the weld and, subsequently, to compute mechanical forces in the longitudinal, lateral and vertical directions. The proposed model includes a coupled thermomechanical modelling. The parametric investigation of the effects of the tool rotational and longitudinal speed on the longitudinal, lateral and vertical forces is also conducted in order to compute the appropriate clamping force applied on the plates. Measurements by the load cells in the longitudinal, lateral and vertical directions are presented and reveal a reasonable agreement between the experimental results and the numerical calculations.


2021 ◽  
Vol 116 ◽  
pp. 00005
Author(s):  
Vladimir Patrushev ◽  
Victor Popov

The process of innovative transformations at an industrial enterprise is studied. The main features of the introduction of innovations into the production process are considered. A general model for carrying out innovative transformations at an industrial enterprise with a large share of high-tech production is proposed. The main elements of the proposed three-dimensional model include the basic processes of change, project and innovation management. Additionally, the models include such processes as: increasing innovation potential, improving internal communications through the introduction of digital technologies, increasing the efficiency of the production process by improving the production system. The applicability of the proposed model under real production conditions is investigated on the basis of Sorbent JSC, and the impact of the implementation of the innovation process on the overall economic efficiency of the enterprise is assessed.


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