CFD Evaluation of Bend Angle Effects on Sand Particle Erosion in Multiphase Flows

Author(s):  
A. Farokhipour ◽  
Z. Mansoori ◽  
M. Saffar-Avval ◽  
S. A. Shirazi ◽  
G. Ahmadi

Abstract In many industrial applications, gas-liquid-particle three-phase flows are observed. Predicting erosion damage in this type of flow is a challenging issue, and so many factors, such as the liquid film behavior have significant effects on the erosion rate. In the present study, the Eulerian-Lagrangian approach was implemented to study the process of sand particle erosion in elbows with different bend angles. For this purpose, gas and liquid phases under annular flow conditions were introduced at the pipe inlet, and the volume of fluid (VOF) method was employed to solve the governing equations. For evaluating the erosion rate, the Det Norske Veritas (DNV) model was applied. The predicted erosion results for the bend angles of 30°, 60° and 90° at different orientations were compared with those of the two-phase gas-particle flows. The simulation results indicated that for gas-liquid-particle flow, the behavior of film thickness in the bend plays a major role on the particle impact velocity and the corresponding erosion rates. By comparing the impact characteristics for gas and liquid superficial velocities of 40 and 0.4 m/s, respectively, in the 90° elbow, it was found that the impact velocities for gas-particle and gas-liquid-particle flows at the erosion hotspot are 38 and 14 m/s, respectively. In addition, among the studied geometries, the 30° elbow is the most erosion-resistant bend angle configuration among those studied for both two- and three-phase flows.

2021 ◽  
Author(s):  
Ali Farokhipour ◽  
Zohreh Mansoori ◽  
Majid Saffar-Avval ◽  
Goodarz Ahmadi ◽  
Siamack Shirazi

2020 ◽  
Vol 143 (8) ◽  
Author(s):  
Kang Shu ◽  
Wen-Jian Wang ◽  
Enrico Meli ◽  
Hao-Hao Ding ◽  
Zhen-Yu Han ◽  
...  

Abstract Usually, rail materials are exactly affected by the erosion of windblown sand in the desert environment. For this reason, the influence of impact angle, particle velocity, and particle size on the erosion wear behavior of the U75V heat-treated rail steel, a material frequently employed in Chinese railways, were studied in this work. The results showed that, with increasing impact angle, the erosion rate increased between 15 deg and 45 deg, decreased between 45 deg and 75 deg, and then increased again between 75 deg and 90 deg. The highest erosion rate occurred at about 45 deg. When the particle velocity increased, the erosion rate increased approximately in a quadratic way. As the sand particle size increased, the erosion rate presented a decreasing trend. During the initial stage of erosion, shear craters, indentation craters, and ploughing craters were the main surface damage features. The shear craters predominated at the impact angle of 45 deg whereas the indentation craters predominated at 90 deg. During the steady-state of erosion, the rail damage was mainly composed of craters, platelets, and cracks. Both the length and depth of craters increased almost linearly with increasing particle velocity, whereas the increased rate of length was significantly higher than that of depth. The length and depth of craters increased with increasing particle size at 90 deg, whereas only the length increased with increasing particle size at 45 deg. The microstructure evolution and the formation mechanism of platelet at low impact angles were different from those at high impact angles. Platelet formation was the main erosion wear mechanism.


Author(s):  
A. Farokhipour ◽  
Z. Mansoori ◽  
M. Saffar-Avval ◽  
M. A. Rasoulian ◽  
A. Rasteh ◽  
...  

Sand particle erosion is the main cause of the failure of bends in the natural gas pipelines. The rapid progress of computational power and modern numerical methods has provided the opportunity for developing realistic simulation of the erosion process. The goal of this paper is to predict the sand erosion rates with the use of computational fluid dynamics in the gas/solid flows in the plugged tees and standard elbows. For this purpose, the Eulerian-Lagrangian approach was used. To simulate the flow, the SIMPLE algorithm and the k-ω SST turbulence model were used. Particles were injected into the inlet pipe with different sizes. To predict more realistic results the Grant and Tabakoff stochastic rebound model was applied and the Oka model was used to calculate erosion. The results showed that, the use of plugged tee instead of a standard elbow would reduce the erosion rate only for fine particles. Also, for them, by increasing the plugged length the pipe will experience less erosion. For coarser particles, however, the vortex created in the plugged section did not affect the particles velocity; therefore, the erosion rate was not reduced.


2021 ◽  
Author(s):  
Marc Willerth ◽  
Briana Dodson ◽  
Kelton McCue ◽  
Mahmoud Farrag

Abstract Appropriate selection of a bottom-hole assembly (BHA) is critical to the success of a drilling operation. In US Land drilling, these assemblies are often selected using local heuristics rather than rigorous analysis. These heuristics are frequently derived from the incentives of the directional contractor as opposed to incentives for the operator. Large motor bends enable more rotation though the curve and reduce the possibility of tripping for build rates. Unstabilized motors are believed to aid sliding and tool face control. Both of these practices lead to drilling a more tortuous wellbore and may cause problems later in the well’s life. This study quantifies the impact of these practices and proposes alternatives that can balance the needs of directional companies with the desire of operators for high-quality wellbores. Over 60 conventional motor assemblies used to drill curves in the Eagle Ford and Permian were analyzed for directional performance using commercial drillstring analysis software. The sliding and rotary tendencies were modelled through the curve across a range of potential drilling conditions. Expected build-rate models were validated by comparison to the maximum achieved doglegs in the directional surveys. When available, additional validation was performed using motor yields calculated from slide sheets. The validated models were compared to the dogleg severity requirements for each assembly’s respective well plan. Comparisons of slide ratios and slide/rotate tendencies of the BHAs were used to estimate the impact on wellbore quality using the tortuosity metric proposed by Jamieson (2019). Typical well plans for both basins had curves of 10 degrees/100ft with no well plan greater than 12 degrees/100ft. Typical bottom hole assemblies were capable of >15 degrees/100ft under normal sliding conditions, with some assemblies capable of >20 degrees/100ft of build. Predicted build rates were validated by slide sheets and observed dogleg severities. Common characteristics among assemblies with excess capacity were high bend angles (>=2 degrees) and minimal stabilization. These slick assemblies also had a strong drop tendency in rotation at low inclinations. The combination of high-build rate with rotary drop greatly increases tortuosity, particularly in the early stages of well. A minority of the assemblies used a lower motor bend angle (<2 degrees) combined with multiple stabilizers. These assemblies had a more consistent directional capability throughout the curve and held angle in rotation. The success of these assemblies confirms that a higher quality wellbore with an improved BHA design is technically achievable. As increasing attention is afforded to the topic of wellbore quality it is important to have methods available to technically achieve high-quality wellbores. In addition to the management of drilling practices, it is also important to have an appropriate BHA design that can enable those practices


Author(s):  
Shunsen Wang ◽  
Guanwei Liu ◽  
Jingru Mao ◽  
Zhenping Feng

This study is concerned with experiments for the relation of solid particle erosion (SPE) and the nozzle profiles. The exfoliated scale from boiler tubing results in hard particles that erode steam turbine components, especially on the control stage nozzles of high parameters turbine. To characterize SPE, solid particle trajectory is measured using particle image velocimetry (PIV) and its relation with the erosion rate of the nozzle surfaces is correlated. In addition, erosion characteristic of nozzle material is investigated by experiments and results reveal that the erosion rate is directly proportional to the impacting velocity of particles with the power of 2.31 and the maximum erosion rate is taken place at the impact angle of 20–25 degree. Furthermore, 0.5% increase in the erosion rate for every one degree of steam temperature rise is observed in the range of 839K∼883K. The erosion rate of front-loaded nozzle A is 2∼3 times higher than that of conventional design nozzle B. The life cycle of nozzle is determined by the erosion of outlet edge, and the life of nozzle B is about 5 times as long as the life of nozzle A. Based on the relation of erosion rate and nozzle profile characteristic, it can be inferred that a aft-loaded nozzle with a contoured endwall substituting a planar endwall may outperform over other nozzle profiles in anti-SPE, prolonging the life cycle of the nozzle.


2014 ◽  
Vol 1049-1050 ◽  
pp. 167-170
Author(s):  
Bao Hui Guo

The solid particle erosion behaviors of TC4 Alloy were studied at different erosion angles. The results show that the erosion rate of TC4 alloy at impact angle 30o was higher than those at the impact angles of both 60o and 90o. At low impact angle, the erosion mechanism could be concluded as grinding erosion and furrow erosion. However, the erosion mechanism could be fatigue erosion at large impact angle.


2011 ◽  
Vol 239-242 ◽  
pp. 1165-1170
Author(s):  
Xiao Qing Lian ◽  
Xiu Mei Feng ◽  
Ming Xue Jiang

Erosion tests on high strengh refractory castables were carried out using SiC grains at impact angles of 30°,45°,60°,and 90° with the velocity of 5m/s.In order to study the variation in stress and system energy with impact angles during solid particle erosion process,a single particle erosion model was designed by means of three-dimensional explicit dynamic software ANSYS/LS-DYNA according to experiment parameters. The Johnson-Holmquist brittle ceramic model was employed to model the failure of target material. The impact angles varied from 15° to 90° in increments of 15°.The simulation results were compared with erosion rate values from experiments. The results show that the variation trends of both the maximum stress of targets and system total energy loss are in a good agreement with experiment data,which increaes with increasing impact angle. The variation of erosion rate as a function of impact angle can be explained by the variation of the maximum stress of target material. The rule “the maximum erosion of typical brittle material occurs at 90°” is confirmed by the view of energy analysis.


Author(s):  
Florian Kuisat ◽  
Fernando Lasagni ◽  
Andrés Fabián Lasagni

AbstractIt is well known that the surface topography of a part can affect its mechanical performance, which is typical in additive manufacturing. In this context, we report about the surface modification of additive manufactured components made of Titanium 64 (Ti64) and Scalmalloy®, using a pulsed laser, with the aim of reducing their surface roughness. In our experiments, a nanosecond-pulsed infrared laser source with variable pulse durations between 8 and 200 ns was applied. The impact of varying a large number of parameters on the surface quality of the smoothed areas was investigated. The results demonstrated a reduction of surface roughness Sa by more than 80% for Titanium 64 and by 65% for Scalmalloy® samples. This allows to extend the applicability of additive manufactured components beyond the current state of the art and break new ground for the application in various industrial applications such as in aerospace.


2021 ◽  
Vol 13 (8) ◽  
pp. 4547
Author(s):  
Mohamed E. El-Sharnouby ◽  
Metwally M. Montaser ◽  
Sliai M. Abdallah

The flower industry depends on oil and fragrance, which is addressed in the current work. Different concentrations of NaCl (0, 250, 500, 1000, and 1500 ppm) were applied to Taif rose plants (Rosa damascena var. trigintipetala Dieck) to evaluate their effects on growth and essential oil content. Results clearly indicated the highest survival percentage (98.3%) was seen in untreated plants compared to plants under salinity stress. Moreover, increasing the NaCl levels induced an adverse effect on the growth parameters of Taif rose plants, while some essential oil contents were increased to the maximum degree of their tolerance to salinity stress. The extracted essential oils were analyzed using GC/MS. The essential oils of Taif rose plants treated with 500 ppm NaCl recorded the highest values of citronellol, geraniol and phenylethyl alcohol contents (16.56, 8.67 and 9.87%), respectively. NaCl at 250 ppm produced the highest values of heneicosane (13.12%), and then decreased to the lowest value (7.79%) with the increase of NaCl to 1500 NaCl, compared to the control and other NaCl levels. The current results could highlight the impact of salinity stress on Rosa damascena Miller var. trigintipetala Dieck for better economic and industrial applications.


Sign in / Sign up

Export Citation Format

Share Document