scholarly journals The effect of the outlet angle β2 on the thermomechanical behavior of a centrifugal compressor blade

2020 ◽  
Vol 29 (1) ◽  
pp. 1-8
Author(s):  
Ahmed Allali ◽  
Sadia Belbachir ◽  
Ahmed Alami ◽  
Belhadj Boucham ◽  
Abdelkader Lousdad
Keyword(s):  
Mechanical Behavior ◽  
Centrifugal Compressor ◽  
Three Dimensional ◽  
Complex Form ◽  
Compressor Blade ◽  
Stress Fields ◽  
The Finite Element Method ◽  
Mechanical Fatigue ◽  
Outlet Angle ◽  
The Impact

AbstractThe objective of this work lies in the three-dimensional study of the thermo mechanical behavior of a blade of a centrifugal compressor. Numerical modeling is performed on the computational code "ABAQUS" based on the finite element method. The aim is to study the impact of the change of types of blades, which are defined as a function of wheel output angle β2, on the stress fields and displacements coupled with the variation of the temperature.This coupling defines in a realistic way the thermo mechanical behavior of the blade where one can note the important concentrations of stresses and displacements in the different zones of its complex form as well as the effects at the edges. It will then be possible to prevent damage and cracks in the blades of the centrifugal compressor leading to its failure which can be caused by the thermal or mechanical fatigue of the material with which the wheel is manufactured.

Investigation on Mechanical Properties of Fibreglass Reinforced Flexible Pipes Under Torsion

2018 ◽  
Author(s):  
Pan Fang ◽  
Yuxin Xu ◽  
Shuai Yuan ◽  
Yong Bai ◽  
Peng Cheng
Keyword(s):  
Mechanical Behavior ◽  
Torsion Angle ◽  
Experimental Studies ◽  
Three Dimensional ◽  
Load Condition ◽  
Element Model ◽  
Flexible Pipe ◽  
Torsional Load ◽  
Flexible Pipes ◽  
The Impact

Fibreglass reinforced flexible pipe (FRFP) is regarded as a great alternative to many bonded flexible pipes in the field of oil or gas transportation in shallow water. This paper describes an analysis of the mechanical behavior of FRFP under torsion. The mechanical behavior of FRFP subjected to pure torsion was investigated by experimental, analytical and numerical methods. Firstly, this paper presents experimental studies of three 10-layer FRFP subjected to torsional load. Torque-torsion angle relations were recorded during this test. Then, a theoretical model based on three-dimensional (3D) anisotropic elasticity theory was proposed to study the mechanical behavior of FRFP. In addition, a finite element model (FEM) including reinforced layers and PE layers was used to simulate the torsional load condition in ABAQUS. Torque-torsion angle relations obtained from these three methods agree well with each other, which illustrates the accuracy and reliability of the analytical model and FEM. The impact of fibreglass winding angle, thickness of reinforced layers and radius-thickness ratio were also studied. Conclusions obtained from this research may be of great practicality to manufacturing engineers.

scholarly journals Modeling of the Mechanical Behavior of 3D Bioplotted Scaffolds Considering the Penetration in Interlocked Strands

2018 ◽  
Vol 8 (9) ◽  
pp. 1422 ◽  
Author(s):  
Saman Naghieh ◽  
M. Sarker ◽  
Mohammad Karamooz-Ravari ◽  
Adam McInnes ◽  
Xiongbiao Chen
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Mechanical Behavior ◽  
Model Development ◽  
Three Dimensional ◽  
The Finite Element Method ◽  
Hydrogel Scaffolds ◽  
Important Index ◽  
Geometrical Features ◽  
Scaffold Structure

Three-dimensional (3D) bioplotting has been widely used to print hydrogel scaffolds for tissue engineering applications. One issue involved in 3D bioplotting is to achieve the scaffold structure with the desired mechanical properties. To overcome this issue, various numerical methods have been developed to predict the mechanical properties of scaffolds, but limited by the imperfect representation of one key feature of scaffolds fabricated by 3D bioplotting, i.e., the penetration or fusion of strands in one layer into the previous layer. This paper presents our study on the development of a novel numerical model to predict the elastic modulus (one important index of mechanical properties) of 3D bioplotted scaffolds considering the aforementioned strand penetration. For this, the finite element method was used for the model development, while medium-viscosity alginate was selected for scaffold fabrication by the 3D bioplotting technique. The elastic modulus of the bioplotted scaffolds was characterized using mechanical testing and results were compared with those predicted from the developed model, demonstrating a strong congruity between them. Once validated, the developed model was also used to investigate the effect of other geometrical features on the mechanical behavior of bioplotted scaffolds. Our results show that the penetration, pore size, and number of printed layers have significant effects on the elastic modulus of bioplotted scaffolds; and also suggest that the developed model can be used as a powerful tool to modulate the mechanical behavior of bioplotted scaffolds.

Thermomechanical Finite Element Analysis of Impact-Induced Magnetic Erasures in Magnetic Storage Thin Film Media

2007 ◽  
Author(s):  
Ning Yu ◽  
Andreas A. Polycarpou ◽  
Jorge V. Hanchi
Keyword(s):  
Finite Element ◽  
Hard Disk Drives ◽  
Three Dimensional ◽  
Thermal Response ◽  
Rotating Disk ◽  
Oblique Impact ◽  
Magnetic Storage ◽  
The Finite Element Method ◽  
Element Analysis ◽  
The Impact

Oblique impact of a slider with a rotating disk in hard disk drives was analyzed using the finite element method. A three dimensional, thermomechanical, impact model was developed to study the mechanical and thermal response during the impact of a spherical slider corner with the disk. The model was validated by comparing finite element results with analytical solutions for homogeneous glass disk under simple conditions. Impact penetration, stress and incurred flash temperature were obtained for various normal impact velocities.

DESIGN STRATEGY OF THREE-DIMENSIONAL PRINTED CAGES TO REDUCE IMPACT-INDUCED DEBRIS ALONG THE LOAD-TRANSFERRING PATH

2021 ◽  
pp. 2050021
Author(s):  
Shang-Chih Lin ◽  
Yu-Pao Hsu ◽  
Ching-Hsiao Yu ◽  
Chun-Ming Chen ◽  
Po-Quang Chen
Keyword(s):  
Finite Element ◽  
Cellular Structure ◽  
Three Dimensional ◽  
Peak Stress ◽  
Transforaminal Lumbar Interbody Fusion ◽  
Design Strategy ◽  
Cellular Structures ◽  
The Finite Element Method ◽  
3D Printed ◽  
The Impact

Peri-implant debris certainly lead to osteolysis, necrosis, pseudotumor formation, tissue granulation, fibrous capsule contractions, and even implant failure. For the three-dimensional (3D) printed cage, impaction during cage insertion is one of the most potential sources of fracture debris. A finite-element study was carried out to reduce the impact-induced debris of the 3D-printed cage. This study focused on the design strategy of solid and cellular structures along the load-transferring path. Using the finite-element method, the cellular structure of the transforaminal lumbar interbody fusion (TLIF) cage was systematically modified in the following four variations: a noncellular cage (NC), a fully cellular (FC) cage, a solid cage with a cellular structure in the middle concave (MC) zone, and a strengthened cage (SC) in the MC zone. Three comparison indices were considered: the stresses at the cage-instrument interfaces, in the MC zone, and along the specific load-transferring path. The NC and FC were the least and most highly stressed variations at the cage-instrument interfaces and in the MC zone, respectively. Along the entirely load-transferring path, the FC was still the most highly stressed variation. It showed a higher risk of stress fracture for the FC cage. For the MC and SC, the MC zone was consistently more stressed than the directly impacted zone. The further strengthened design of the SC had a lower peak stress (approximately 29.2%) in the MC zone compared with the MC. Prior to 3D printing, the load-transferring path from the cage-instrument interfaces to the cage-tissue interfaces should be determined. The cage-instrument interfaces should be printed as a solid structure to avoid impact-induced fracture. The other stress-concentrated zones should be cautiously designed to optimize the coexistence strategy of the solid and cellular structures.

Multi-Disciplinary Optimization of a Centrifugal Compressor for Micro-Turbine Applications

2016 ◽  
Author(s):  
Andrea Perrone ◽  
Luca Ratto ◽  
Gianluca Ricci ◽  
Francesca Satta ◽  
Pietro Zunino
Keyword(s):  
Mechanical Behavior ◽  
Centrifugal Compressor ◽  
Transport Model ◽  
Three Dimensional ◽  
Optimization Procedure ◽  
Aerodynamic Performance ◽  
Multidisciplinary Optimization ◽  
Navier Stokes ◽  
Phase Lag ◽  
High Rotational Speed

The present paper presents the multi-disciplinary optimization of a centrifugal compressor for a 100kW micro gas turbine. The high rotational speed fixed by the cycle optimization (75,000 rpm) required a simultaneous analysis of flow aerodynamics and mechanical behavior to account for the high centrifugal stresses the blades are subjected to, while maximizing the aerodynamic performance. A commercial 3D (three dimensional) computational fluid dynamics (CFD) solver adopted for the aerodynamic computations and an open source finite element FEM code for the mechanical integrity calculations have been coupled with metamodels to speed up the optimization process. Home-made scripting modules, which manage multidisciplinary optimization, mesh generation, geometry parameterization and result post-processing have been written and utilized. A sample data-base has been generated on the basis of the parameters selected to describe aerodynamic and mechanical constraints, and an optimization procedure based on a genetic algorithm has been performed. A RANS (Reynold Averaged Navier Stokes) steady approach with a two-equation SST (Shear Stress Transport) model has been adopted for the aerodynamic computations during the optimization procedure. The optimized compressor so achieved showed an important boost in aerodynamic performance, without any penalty in the mechanical behavior, as compared with the preliminary design. The optimized configuration has been tested also by means of URANS (Unsteady Reynolds Averaged Navier Stokes) phase-lag investigations, which confirmed the aerodynamic performance increase predicted by steady RANS calculations.

Aerodynamic Analysis of a Multistage Centrifugal Compressor

2003 ◽  
Author(s):  
Duccio Bonaiuti ◽  
Andrea Arnone ◽  
Alberto Milani ◽  
Leonardo Baldassarre
Keyword(s):  
Flow Field ◽  
Centrifugal Compressor ◽  
Three Dimensional ◽  
Operating Range ◽  
Aerodynamic Analysis ◽  
Critical Elements ◽  
Multi Stage ◽  
The One ◽  
Multistage Centrifugal Compressor ◽  
The Impact

The aerodynamic analysis of a four–stage centrifugal compressor was performed by means of a three–dimensional multi stage CFD code. The whole operating range of the compressor was investigated and the critical elements affecting the choke and stall limit were identified. The isolated impellers were also analyzed separately and the flow field was compared to the one coming from the multistage analysis. This allowed us to study the effect of the interactions between components and quantify the impact of the multistage environment on the impellers’ performance.

scholarly journals Stress concentration in the vicinity of road сoating cracks

2021 ◽  
pp. 41-53
Author(s):  
Viktor Gaidaichuk ◽  
Liudmyla Shevchuk ◽  
Olena Bilobrytska ◽  
Serhii Baran
Keyword(s):  
Stress Concentration ◽  
Mechanical Behavior ◽  
Asphalt Concrete ◽  
Plastic Material ◽  
Multilayer Coating ◽  
Three Dimensional ◽  
Element Model ◽  
Operating Conditions ◽  
The Road ◽  
The Impact

The article presents the results of a computer analysis of the stress-strain state of a multilayer asphalt pavement under the influence of traffic loads. Based on the finite-element model of coating deformation, a study was made of the mechanical behavior of the system considered for various structural schemes for the existence of vertical cracks in various layers of the structure under the action of vertical transport loads. The effects of stress concentration in the system due to high-gradient deformation fields and structural imperfections of the multilayer coating were found. Multi-layer asphalt roads are one of the most common construction projects. Based on a review of the tasks of science about their strength and durability, these structures can be attributed to significantly complex types of building systems. This is primarily due to the multi-parameter nature of the factors that determine their design, material properties, types of loads and the impact on them, as well as their operating conditions. Therefore, designers of road structures and specialists who are involved in the theoretical modeling of the mechanical behavior of layered massifs during operation have to take into account many additional factors that complicate their work. These include the most important design and operational features of these systems, which significantly affect the nature of the distribution of stress and strain fields, as well as their intensity. First of all, they include special structural schemes of the road and pavement. It is a multilayer three-dimensional package having disproportionately different sizes along each direction. Hidden (as well as obvious) vertical cracks and horizontal delamination of the structure, sometimes permissible under operating conditions, can be added to the design model of a structure. Such violations of the continuity of the system also lead to discontinuity of the displacement functions, which further worsens the system’s performance and complicates the task of its modeling. The materials of the coating layers, which include asphalt concrete, cement, crushed stone, sand, soil, and others, also bring particular specificity to the work of the road structure. All of them differently resist tensile, compression and shear, and asphalt concrete is also elastic-viscous - plastic material, whose properties are largely dependent on temperature.

scholarly journals Numerical analysis of the behavior of a three-layer honeycomb panel with interlayer defects under action of dynamic load

2021 ◽  
Vol 17 (4) ◽  
pp. 357-365
Author(s):  
Aleksandr L. Medvedskiy ◽  
Mikhail I. Martirosov ◽  
Anton V. Khomchenko ◽  
Darina V. Dedova
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Impact Load ◽  
Geometric Model ◽  
Three Dimensional ◽  
Element Model ◽  
Failure Criteria ◽  
Stress Fields ◽  
The Impact ◽  
Honeycomb Panel

The aim of the work is to study the effect of interlayer defects of the bundle type on the behavior of a rectangular flat three-layer panel with a honeycomb filler under the influence of a dynamic impact load. Methods. The problem was solved numerically using the finite element method in the Simcenter Femap and LS-DYNA (Livermore Software Technology Corp.) software complexes. For this purpose, a geometric model of a panel with a honeycomb placeholder was developed. Based on the geometric model, a finite element model of the panel was created using three-dimensional finite elements. In the software complexes, the finite element model was calculated under specified boundary conditions, then the stress fields and fracture indices in the panel were determined, taking into account and without taking into account damage. Results. The stress fields in the panel are numerically determined with and without defects. The fields of the failure indices of the panel layers under the impact load are investigated using various failure criteria (Puck, Hashin, LaRC03 (Langley Research Center)) of polymer composite materials. The analysis of the influence of a defect on the behavior of a honeycomb panel under the impact load is carried out.

Performance-Based Geometric Tolerancing of Compressor Blades

2004 ◽  
Author(s):  
Caroline Twomey Lamb ◽  
David L. Darmofal
Keyword(s):  
Geometric Model ◽  
Three Dimensional ◽  
Aerodynamic Performance ◽  
Compressor Blade ◽  
Geometric Parameters ◽  
Performance Limits ◽  
Compressor Blades ◽  
Performance Limit ◽  
Geometric Tolerancing ◽  
The Impact

The relationship between statically measured geometric parameters (tolerances) and the aerodynamic performance of an airfoil are investigated in this paper. The goal is to determine which geometric parameters are critical to control during manufacturing, such that a blade will have acceptable aerodynamic performance. A probabilistic model of geometric variability for a three-dimensional blade is derived. Using this geometric model, probabilistic aerodynamic simulations are conducted to analyze the variability in aerodynamic performance. Tolerance optimization is then applied in which tolerance ranges are modified to best sort blades according to some arbitrary performance limit. The optimization is performed for several limits, expressed as a percent of nominal performance, to observe both which parameters best predict performance and the accuracy of that prediction at each limit. Two blade cases are considered, both based on the same compressor blade: the base compressor blade with nominal manufacturing noise; and a probabilistic redesign of the blade geometry designed to minimize the impact of manufacturing noise, also analyzed with nominal manufacturing noise. Results show the best static indicators of meanline performance are parameters concerning the LE of the airfoil, and the effectiveness of these parameters vary greatly depending on the chosen performance limit. In addition, it was shown that the optimized tolerances for the redesigned blade were consistently looser, or less restrictive, than those for the original blade population for a given performance limit. The differences in observed optimized tolerance ranges are small for less restrictive performance limits but at more aggressive performance limits, there is a 20–30% increase in tolerance range for the redesigned blade population.

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