Numerical Simulation of the effect of L-shaped spur dike wing length on scouring at a 90 ° bend.

Spur dike is one of the common structures in organizing and controlling erosion on the river bank. On the other hand, the placement of the spur dike in the bended part of the river, while removing strong currents from the shore and directing the flow to the river axis, also changes the flow pattern and scour around the spur dike. The aim of this study was to numerically investigate the effect of length change in L-shaped Spur dike wing on scour depth located in a channel with a 90° bend. For this purpose, the three-dimensional SSIIM numerical model was used for simulation. L-shaped spur dikes with different wing lengths were tested and simulated. At the end, the outputs of the numerical model were compared with the laboratory results and validated. The results while confirming the SSIIM numerical model in scour simulation around the spur dike showed that by increasing the length of the spur dike wing and decreasing the angle of the spur dike in the bend, the depth and volume of the scour decreases significantly. In addition, the maximum depth and volume of scour around the spur dike was recorded at a 90 ° angle with a length to web ratio of 0.5. On the other hand, in all cases, scour around the simple spur dike was more than the L-shaped spur dike with different wing lengths

Carbon Dioxide Geological Storage (CGS) – Current Status and Opportunities

Carbon dioxide sequestration has gained a great deal of global interest because of the needs and applications of mitigation strategy in many areas of human endeavors including capture and reduction of CO2 emission into atmosphere, oil and gas enhanced production, and CO2 geological storage. In recent years, many developed countries as well as some developing ones have extensively investigated all aspects of the carbon dioxide geological storage (CGS) process such as the potential of storage sites, understanding the behavior of CO2, and its interaction with various formations comprising trapping mechanisms, flow pattern, and interactions with formation rocks and so on. This review presents a summary of recent research efforts on storage capacity estimation techniques in most prominent storage options (depleted oil and gas reservoir, saline aquifers and coal beds), modeling and simulation means followed by monitoring and verification approaches. An evaluation of the more interesting techniques which are gaining attention in each part is discussed

The Association Between Dietary Energy Density and Musculoskeletal Pain in Adult Men and Women

Musculoskeletal pains (MPs), defined as persistent or recurrent pain, is a complex health problem. High overall calorie and fat intake have been related to obesity and MPs. Dietary energy density (DED), defined as energy content of food and beverages (in kcal) per unit total weight, has been associated with chronic muscle, cartilage, bone damage and pain. Thus, the purpose of this study is to investigate the association between DED and MPs in adult men and women. A total of 175 men and women (> 18 years) with MP participated in the study. A validated short form physical activity (PA) questionnaire, demographic, and McGill Pain Questionnaire were used. Anthropometric measurements were evaluated via standard protocols. Furthermore, a seven-day 24-hour recall of diet was used to determine the dietary intake. Total DED was calculated and divided into quartiles. Linear regression was used to discern the association between DED and MPs in adults. Participants assigned in the highest category of DED were characterized by lower intake of potassium, magnesium, vitamin C, folate, and fiber. However, results showed displayed higher intake of sodium, vitamin E, vitamin B3, fat, protein, cholesterol, saturated fatty acids, monounsaturated fatty acids, and polyunsaturated fatty acids (p < 0.001). Finally, after adjustment for confounders such as age, gender, PA, body mass index, waist circumference, education, job, marital status, history of some chronic diseases and vitamin C supplementation, a significant positive association was detected between DED and pain intensity. There was no significant association between DED and pain frequency in all models

Application of numerical model in determining the discharge coefficient containing suspended sediments passing through side weirs

Side weirs are one of the most common water structures that are used to transfer or pass flood and excess water from headwater to downstream in channels and dams. One of the factors, which is often less considered in the design of such weirs, is the amount of suspended load along with the flow. Basically, suspended sediments along with the flow, in addition to changes in the density of the passing water, can change most of the assumptions in the design of weirs. Due to the high cost and time-consuming nature of physical modeling, the powerful Flow-3D numerical model was used to simulate the flow of suspended sediments in this study. A channel with a side weir was modeled according to laboratory conditions and the discharge coefficient passing through the side weir at different concentrations of the suspended load was calculated. The results, while confirming the ability of the Flow-3D numerical model to simulate the flow containing sediment passing through the side weirs, showed that with increasing the concentration of suspended flow load, the discharge coefficient passing through the side weir increases. Also, increasing the weir’s height along with increasing the concentration of suspended sediments has led to a significant increase in the discharge coefficient passing through the side weir

Experimental and Numerical Investigation of Local Scouring around Bridge Piers in Different Geometric Shapes at a 90° Convergent meander

The presence of several convergent meanders is a basic characteristic of natural flowing rivers. It is important to construct bridge piers in different geometric shapes at convergent meanders. The formation of secondary flows at meanders and their enhancement by the convergence effect can bring complexities and irregularity in the erosion pattern around bridge piers. The present study experimentally and numerically investigates the effects of the geometric shapes of bridge piers on local scour around piers at a 90° convergent meander. Tests were carried out within a channel with a 90° convergent meander and a centerline radius of 170 cm. Cylindrical piers with the diameters of 40 and 60 mm and cubic piers with the sizes of 40*40 and 60*60 mm were placed at the center of the meander, investigating scour in clear-water conditions. Also, a three-dimensional SSIIM-2 model was employed to simulate the problem and compare the results to the experimental ones. The results indicated that the shapes and sizes of the piers affected the scour depth, and the maximum scour depth was estimated to be smaller around the cylindrical piers than around the cubic piers in all the tests. Moreover, convergence-induced contraction along with the placement of the piers at the meander enhanced scour around the piers. The numerical SSIIM-2 results were found to be in a good agreement with the experimental results

Application of SSIIM numerical model in simulation of local scouring around the aerodynamic bridge pier located in 90 ° bend

Bridges are one of the most important and widely used river structures. Every year, a large number of them are destroyed by factors such as scouring and erosion. It is sometimes observed that the bridges are placed in the river bend, due to restrictions such as the road construction or river instability. On the other hand, studies have shown that the geometric shape of the bridge pier will have significant effect on the depletion of flow energy and thus reduce the scour depth around the bridge pier. Therefore, in this study, the effect of bend angle changes on flow pattern and local scouring around the of cylindrical bridge piers with aerodynamic shapes were investigated. SSIIM Three-dimensional software was used for modeling. The results showed that by increasing the bend angle and also placing the pier with a wide nose upstream, the amount of depth and volume of scouring increases, so that, the maximum depth and volume of scour occurred at a 90-degree angle to 0.1197123m and 0.08436892m3, respectively

Investigating drainage rate effects on fractal patterns and capillary fingering in a realistic glass micromodel

Ispravna karakterizacija postupaka i mehanizama istiskivanja fluida razmjera pora je od bitne važnosti za razumijevanje i opisivanje ponašanja pri istiskivanju kod većih mjera jezgre i rezervoara. Detaljno vizualno ispitivanje fenomena istiskivanja može se ostvariti jedino korištenjem staklenih mikromodela stvarnih dimenzija sličnih onom razvijenom u ovom radu. Provedena su razna ispitivanja brzine drenaže s fluidima iste viskoznosti u svrhu promatranja uzoraka toka u vodom ovlaženom staklenom mikromodelu. Potpuno zasićenje St, lokalna zasićenja Sx, prednja fraktalna dimenzija Df i površinska fraktalna dimenzija Ds, izračunati su iz slika testova visoke rezolucije i upotrijebljeni za kvalitativnu i kvantitativnu procjenu postupaka. Ustanovljeno je da St i Ds prate trendove porasta, a staze Df trend opadanja s kapilarnim brojem. To se događa zbog stabilnijih uzoraka i kompaktnih struktura koje se razvijaju u testovima s većim brzinama ubrizgavanja. Krivulje Sx su, međutim, ostale usporedive kod različitog broja kapilarnih testova zbog istog uzorka mreže primijenjenog u svim eksperimentima. Napredne fraktalne mjere zajedno sa slikama eksperimenata visoke rezolucije omogućile su da se precizno opišu i istraže uzorci i strukture istiskivanja kako se stvaraju i s vremenom razvijaju pri različitim kombinacijama kapilarnih i viskoznih sila na koje se najvjerojatnije nailazi u stvarnim uvjetima spremišta.Proper characterization of fluid displacement processes and mechanisms at pore scale is essential to understand and describe the displacement behaviour at larger core and reservoir scales. Detailed visual investigation of displacement phenomena is only realized using real-size glass micromodels similar to what we developed in this study. Different drainage rate experiments are performed with viscosity match fluids to observe flow patterns in a water-wet glass micromodel. Total saturation St, local saturations Sx, front fractal dimension Df and surface fractal dimension Ds, are calculated from high resolution images of the tests and are used for the qualitative and quantitative evaluation of the processes. It is found that St and Ds follow increasing trends and Df tracks a decreasing trend with capillary number. This is due to the more stable patterns and compact structures that are developed in the tests with higher injection rates. Sx curves, however, remained comparable for different capillary number tests due to the same network pattern used in all the experiments. Advanced fractal measures along with high resolution images of the experiments made it possible to precisely describe and investigate the displacement patterns and structures as they initiate and develop with time at different combinations of capillary and viscous forces most likely encountered in real reservoir conditions

Experimental and numerical investigation the effect of pier position on local scouring around bridge pier at a 90° convergent bend

Natural rivers have several bends along the path that are not generally uniform and some are convergent. Installing the bridge piers in river convergent bends may result in complicated flow and erosion patterns around the bridge piers. Most of previous studies on the flow and the scour pattern around piers were carried out in straight channels and fixed-width bends. Studying the local scouring around pier located at a converging bend, experimentally and numerically, has brought novelty to this paper. In this research, a physical hydraulic model with a 90° convergent bend and central radius of 170 cm was built. A cylindrical pier with a diameter of 60 mm was installed in positions of 0, 30, 45, 60, and 75 degrees and local scour were studied under clear-water conditions. The SSIIM-2 numerical model was also used to simulate the scour pattern and the results were compared with experimental results. The results showed that, increasing the convergence and changing the pier position in a bend leads to an increment in the continuity between the flow lines and secondary currents, respectively, so that the maximum depth and volume of the scour hole occurred in the second half of the bend at an angle of 75 degrees. The comparison between experimental and numerical data shows that SSIIM-2 model can efficiently simulate the scour pattern in a 90° convergent bend. Furthermore, in all cases by increasing the Froude number, maximum depth and volume of the scour hole were increased