Study on Process of Particle Impact on Curved Surface of Vane by Finite Element Method

2010 ◽  
Vol 139-141 ◽  
pp. 1303-1307
Author(s):  
Xiao Jing Yang ◽  
Yi Lin Chi ◽  
Guan Zhang He
Keyword(s):  
Particle Size ◽  
Energy Exchange ◽  
Surface Deformation ◽  
Plastic Property ◽  
Impact Angle ◽  
Surface Shape ◽  
Curved Surface ◽  
Particle Impact ◽  
Size Of Particles ◽  
Distribution Of Stress

The process of particle impacting and contacting curved surface of vane was studied, and the characteristics of particle size, particle initial velocity and its impacting direction affect the stress of subsurface were analyzed by using ANSYS/LS-DANY software. It is shown that the interaction between particles and surface of vane is affected by nonlinear factors such as the elastic-plastic property of material, the state of impacting and contacting and surface shape. The increment in particle size increases the stress of the surface impacted and the sphere of action is also enlarged. The influence of the size of particles is remarkable. Particle impact velocity is related to energy exchange and has influences on stress value and the area of surface deformation. Due to impact angle is related to shape of curved vane, so the distribution of stress is changed and the value of the stress in surface layer is also influenced when particles impact curved surface of vane from different directions. The research will be helpful to disclose the mechanics of the wear on the condition of particle impact.

Residual Stress in Bone: A Parametric Study

2008 ◽  
Author(s):  
A. Hizal ◽  
B. Sadasivam ◽  
D. Arola
Keyword(s):  
Residual Stress ◽  
Particle Size ◽  
Residual Stresses ◽  
Material Removal ◽  
Surface Deformation ◽  
Radius Of Curvature ◽  
Near Surface ◽  
Size And Shape ◽  
Air Jet ◽  
Particle Size And Shape

A preliminary study was conducted to evaluate the parametric dependence of the residual stress distributions in bone that result from an abrasive air-jet surface treatment. Specifically, the influence of particle size and shape used in the treatment on the residual stress, propensity of embedding particles and material removal were studied. Rectangular beams of cortical bone were prepared from bovine femurs and treated with aluminum oxide and glass particles with different treatment angles. Residual stresses within the bone were quantified in terms of the radius of curvature of the bone specimens measured before and after the treatments, as well as a function of time to quantify decay in the stress. The sub-surface distribution was also examined using the layer removal technique. Results showed that the particle size and shape could be used to control the amount of material removal and the magnitude of residual stress within the treated surfaces. An increase in size of the glass particles resulted in an increase in the residual stress and a decrease in material removed during the treatment. The magnitude of residual stress ranged from 22 MPa to nearly 44 MPa through modulation of the particle qualities (size and shape). A microscopic examination of the treated surfaces suggests that the residual stresses resulted primarily from near-surface deformation.

Multiple-Points Constraints Based Deformation for Free-Form Surfaces

1999 ◽  
Author(s):  
J. M. Zheng ◽  
K. W. Chan ◽  
I. Gibson
Keyword(s):  
Surface Deformation ◽  
Single Point ◽  
Displacement Function ◽  
Surface Shape ◽  
Free Form ◽  
Surface Model ◽  
Deformation Method ◽  
Multiple Points ◽  
Free Form Surface ◽  
Free Form Surfaces

Abstract There is an increasing demand in the conceptual design for more intuitive methods for creating and modifying free-form curves and surfaces in CAD modeling systems. The methods should be based not only on the change of the mathematical parameters but also on the user’s specified constraints and shapes. This paper presents a new surface representation model for free-form surface deformation representation. The model is a combination of two functions: a displacement function and a function for representing an existing NURBS surface called parent surface. Based on the surface model, the authors develop two deformation methods which are named SingleDef (Single-point constraint based deformation method), and MultiDef (Multiple-points constraints based deformation method). The techniques for free-form surface deformation allow conceptual designer to modify a parent surface by directly applying point constraints to the parent surface. The deformation methods are implemented and taken in an experimental CAD system. The results show that the designer can easily and intuitively control the surface shape.

scholarly journals A Methodology for Multi-Camera Surface-Shape Estimation of Deformable Unknown Objects

Robotics ◽  
2018 ◽  
Vol 7 (4) ◽  
pp. 69 ◽  
Author(s):  
Evgeny Nuger ◽  
Beno Benhabib
Keyword(s):  
Particle Filtering ◽  
Surface Deformation ◽  
Vision System ◽  
Three Dimensional ◽  
Target Object ◽  
Surface Shape ◽  
Shape Estimation ◽  
Formal Approach ◽  
Camera System ◽  
Unknown Objects

A novel methodology is proposed herein to estimate the three-dimensional (3D) surface shape of unknown, markerless deforming objects through a modular multi-camera vision system. The methodology is a generalized formal approach to shape estimation for a priori unknown objects. Accurate shape estimation is accomplished through a robust, adaptive particle filtering process. The estimation process yields a set of surface meshes representing the expected deformation of the target object. The methodology is based on the use of a multi-camera system, with a variable number of cameras, and range of object motions. The numerous simulations and experiments presented herein demonstrate the proposed methodology’s ability to accurately estimate the surface deformation of unknown objects, as well as its robustness to object loss under self-occlusion, and varying motion dynamics.

The impact angle dependence of erosion damage caused by solid particle impact

Wear ◽  
1997 ◽  
Vol 203-204 ◽  
pp. 573-579 ◽  
Author(s):  
Y.I. Oka ◽  
H. Ohnogi ◽  
T. Hosokawa ◽  
M. Matsumura
Keyword(s):  
Solid Particle ◽  
Impact Angle ◽  
Particle Impact ◽  
Erosion Damage ◽  
Angle Dependence ◽  
The Impact

Experimental Investigation on the Influence of Particle Size in a Submerged Slurry Jet on Erosion Rates and Patterns

2017 ◽  
Author(s):  
Soroor Karimi ◽  
Amir Mansouri ◽  
Siamack A. Shirazi ◽  
Brenton S. McLaury
Keyword(s):  
Particle Size ◽  
Erosion Rate ◽  
Erosive Wear ◽  
Impact Angle ◽  
Piping System ◽  
Slurry Erosion ◽  
Material Particle ◽  
Impact Speed ◽  
Effect Of Particle Size ◽  
Sand Particles

Sand particles entrained in fluids can cause erosive wear and damage to piping materials by impacting their surfaces which could result in failure of the piping system. Several parameters have been determined to affect the erosion behavior and mechanism of solid particle erosion. Some of these parameters include surface material, particle impact speed and angle, and particle size, shape and hardness. However, the effect of particle size on the total erosion rate and local erosion pattern has not been thoroughly investigated. It has been observed that sand particles with various sizes cause different slurry erosion patterns. Changing the particle size alters the Stokes number and consequently produces different erosion patterns and magnitudes. Thus, the effects of particle size on total erosion rate and erosion pattern in a submerged slurry jet are investigated for different impingement angles. Experiments are performed on 316 stainless steel specimens for average particles sizes of 25, 75, 150, and 300 μm. The jet angle is varied to 45, 75 and 90 degrees, and the slurry jet velocity is set to 14 m/s. The erosion pattern of the specimen is examined by obtaining the 3D microscopic profile of the eroded specimen by means of an optical profiler. It is found that the erosion profile changes as the jet angle varies. It is also observed that erosion profile is significantly different for smaller particles as compared to the larger particles. Moreover, these differences become more pronounced as the jet angle decreases. The present work discusses the differences of erosion patterns produced by both large and small particles. Computational Fluid Dynamics (CFD) is also used to study the effect of particle size on particle trajectories, impact speed, and impact angle. Also, CFD results help in explaining the differences observed in the erosion profiles caused by different particle sizes.

An Investigation on the Application of Cryogenic Ball Milling to Ibuprofen Particle and Its Characteristics

2006 ◽  
Vol 505-507 ◽  
pp. 355-360 ◽  
Author(s):  
Kyong Yop Rhee ◽  
Hyun Kab Cho ◽  
Jai Sung Hong
Keyword(s):  
Particle Size ◽  
Ball Milling ◽  
Weight Ratio ◽  
Milling Process ◽  
X Ray Diffraction ◽  
Chemical Changes ◽  
Ball Milling Process ◽  
Particle Size Analyzer ◽  
Before And After ◽  
Size Of Particles

For a present study, a cryogenic ball milling process was applied to reduce the Ibuprofen particles to submicron in order to enlarge their dissolution rate. The cryogenic ball milling was performed using 6 mm zirconia balls at a temperature of -180 °C or lower. The effects of milling time, the weight ratio of ball to Ibuprofen, and milling speed on the particle size were investigated. SEM and particle size analyzer were used to analyze the shape and size of particles before and after ball milling. The chemical changes before and after the cryogenic ball milling process were examined through XRD (x-ray diffraction) analysis. The results show that the size of Ibuprofen particles was reduced to about 1/20 of its initial size and the particle size showed negligible change after six hours of ball milling. The effect of weight ratio and the milling speed on the particle size was almost negligible. The results also show that cryogenic ball milling yielded no chemical changes in the particle.

scholarly journals Impact Angle Dependence of Erosion by Solid Particle Impact for Metallic Materials

1999 ◽  
Vol 48 (6) ◽  
pp. 355-361 ◽  
Author(s):  
Yoshinori Isomoto ◽  
Miyuki Nishimura ◽  
Kazuo Nagahashi ◽  
Masanobu Matsumura
Keyword(s):  
Solid Particle ◽  
Impact Angle ◽  
Particle Impact ◽  
Metallic Materials ◽  
Angle Dependence

scholarly journals Physicochemical and Microstructural Properties of Polymerized Whey Protein Encapsulated 3,3′-Diindolylmethane Nanoparticles

Molecules ◽  
2019 ◽  
Vol 24 (4) ◽  
pp. 702 ◽  
Author(s):  
Abbas Khan ◽  
Cuina Wang ◽  
Xiaomeng Sun ◽  
Adam Killpartrick ◽  
Mingruo Guo
Keyword(s):  
Particle Size ◽  
Zeta Potential ◽  
Whey Protein ◽  
Surface Shape ◽  
Core Material ◽  
Microstructural Properties ◽  
Brussels Sprouts ◽  
Mean Particle Size ◽  
Mass Ratios ◽  
Repulsive Forces

The fat-soluble antioxidant 3,3′-diindolylmethane (DIM), is a natural phytochemical found in Brassica vegetables, such as cabbage, broccoli, and Brussels sprouts. The stability of this compound is a major challenge for its applications. Polymerized whey protein (PWP)-based DIM nanoparticles were prepared at different mass ratios of protein and DIM by mixing PWP and DIM followed by ultrasound treatment for 4 min. All the nanoparticles were studied for particle size, zeta potential, rheological and microstructural properties, and storage stability. The mean particle size of the PWP-based nanoparticles was significantly increased (p < 0.05) by the addition of DIM at different mass ratios, ranging from 241.33 ± 14.82 to 270.57 ± 15.28 nm. Zeta potential values of all nanoparticles were highly negative (greater than ±30 mV), suggesting a stable solution due its electrostatic repulsive forces. All samples exhibited shear thinning behavior (n < 1), fitted with Sisko model (R2 > 0.997). Fourier Transform Infrared (FTIR)spectra revealed that the secondary structure was changed and the absorption intensity for hydrogen bonding got stronger by further incorporating DIM into PWP. Transmission electronic microscopy (TEM) images showed spherical and smooth surface shape of the PWP-based nanoparticles. DIM encapsulated by PWP showed enhanced stability at 4, 37 and 55 °C for 15 days evidenced by changes in mean particle size and color (a*-value and b*-value) compared with control (DIM only). In conclusion, the polymerized whey protein based 3,3′-diindolylmethane nanoparticles are stable and the encapsulation may protect the core material from oxidation.

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