پیوندهای مفید
آمار
| تعداد نشریات | 9 |
| تعداد شمارهها | 447 |
| تعداد مقالات | 5,734 |
| تعداد مشاهده مقاله | 8,049,306 |
| تعداد دریافت فایل اصل مقاله | 6,548,595 |
شبیهسازی عددی جریان گلآلود سهبعدی حاوی دو نوع ذره در یک کانال آزمایشگاهی در حضور مانع | ||
| نشریه مهندسی مکانیک امیرکبیر | ||
| مقاله 16، دوره 52، شماره 7، مهر 1399، صفحه 1955-1974 اصل مقاله (2.29 M) | ||
| نوع مقاله: مقاله پژوهشی | ||
| شناسه دیجیتال (DOI): 10.22060/mej.2018.14882.5967 | ||
| نویسندگان | ||
| صبا تیموری1؛ احسان خواصی* 2 | ||
| 1مهندسی مکانیک، دانشگاه زنجان، زنجان، ایران | ||
| 2گروه مهندسی مکانیک، دانشکده فنی و مهندسی، دانشگاه زنجان | ||
| چکیده | ||
| در این پژوهش انتشار جریان چگال پیوسته سهبعدی حاوی دو نوع ذره در برخورد با مانع به روش گردابههای بزرگ و با استفاده از کد اپن فوم، بهصورت عددی مدلسازی شدهاست. به علت تعداد زیاد ذرات معلق، از روش اویلری- اویلری استفاده شده است و برای هر نوع ذره یک معادله غلظت، که دارای پارامتر سقوط ذرات است، حل میشود. نتایج نشان میدهند که قبل از مانع تغییر چندانی در پروفیل سرعت جریان در حالت با مانع و بدون مانع ایجاد نمیشود، ولی حضور مانع سرعت ماکزیمم جریان را 10 درصد کاهش میدهد. همچنین بار ذرات معلق نیز در عرض کانال برروی مانع کاهش مییابد. در حالت شبه پایدار نهایی، غلظت ماکزیمم (بعد از مانع) 15/3 درصد نسبت به حالت بدون مانع کاهش یافته است. با افزایش قطر ذرات تا 20 و 30 میکرون، ماکزیمم غلظت به ترتیب 12/5 و 22/3 درصد افزایش مییابد. بار ذرات معلق نیز برای ذرات با قطر 20 و 30 میکرون به ترتیب 21 و 68 درصد کاهش مییابد. در نتیجه ذرات با قطر بیشتر، زودتر و بیشتر رسوب میکنند. تغییر غلظت ورودی در حالت ذره با قطر کمتر، موجب افزایش بار ذرات معلق به میزان 11/2 درصد شده و جریان قابلیت حمل بار معلق بیشتری را خواهد داشت. | ||
| کلیدواژهها | ||
| جریان چگال پیوسته؛ مانع؛ آشفتگی؛ ذرات؛ شبیهسازی گردابههای بزرگ | ||
| عنوان مقاله [English] | ||
| Numerical Simulation of Three-Dimensional and Bi-Disperse Particle-Laden Turbidity Current in an Experimental Channel in the Presence of an Obstacle | ||
| نویسندگان [English] | ||
| Saba Teymouri1؛ Ehsan Khavasi2 | ||
| 1Department of Mechanical Engineering, University Of Zanjan, Zanjan, Iran. | ||
| 2Mechanical engineering department, University of Zanjan | ||
| چکیده [English] | ||
| In the present study, the propagation of a continuous three-dimensional, in collision with obstacle and bi-disperse particle-laden turbidity current with a large eddy simulation method was modeled using the OpenFOAM numerically. Due to the presence of a large number of suspended particles, the Eulerian-Eulerian method has been used and for each particle a concentration equation, which the particles settling velocity has been added to, is solved. The results show that before the obstacle, there is no significant change in the current velocity profiles in with and without obstacle state, but the presence of an obstacle decreases the maximum velocity by 10%, also the number of suspended particles on the obstacle decreases in channel width. In the final semi-stable state, the maximum concentration of 15.3% is reduced compared to the without obstacle state. By increasing the particle diameter to 20 and 30 microns, maximum concentration is increased by 12.5% and 22.3%, the number of suspended particles also decreases by 68% and 21%, respectively. As a result, particles with larger diameter precipitate more and rapidly. Changing the inlet concentration in the case of smaller diameter particle increases the number of suspended particles by 11.2% and current will have more capability for carrying suspended particles. | ||
| کلیدواژهها [English] | ||
| Density continuous current, Obstacle, Turbidity, Particles, Large eddy simulation | ||
| مراجع | ||
|
[1] J. Zordan, C. Juez, A. J. Schleiss, and M. J. Franca, Entrainment, transport and deposition of sediment by saline gravity currents, Advances in Water Resources 115 (2018) 17-32. [2] L. Ottolenghi, C. Adduce, R. Inghilesi, V. Armenio, and F. Roman, Entrainment and mixing in unsteady gravity currents, J. Hydraul. Res 54 (5) (2016) 541– 557. [3] J. Pelmard, S. Norris, and H. Friedrich, LES grid resolution requirements for the modelling of gravity currents, Computers & Fluids 174 (30 September) (2018) 256-270. [4] M. Mahdinia, B. Firoozabadi, M. Farshchi, A.G.Varnamkhasti, Large Eddy Simulation of LockExchange Flow in a Curved Channel, J. Hydraul. Eng 138 (1) (2011) 57–70. [5] L. Ottolenghi, C. Adduce, R. Inghilesi, F. Roman, and V. Armenio, Mixing in lock-release gravity currents propagating up a slope, Phys. Fluids 28(5) (2016). [6] G. Gonzalez-Juez, E., Meiburg, E., and Constantinescu, Gravity currents impinging on bottom-mounted square cylinders: Flow fields and associated forces, J. Fluid Mech 631(2009) 65–102. [7] M. Nasr-Azadani and E. Meiburg, Influence of seafloor topography on the depositional behavior of bi-disperse turbidity currents: a three-dimensional , depth-resolved numerical investigation, Environ. Fluid Mech 14 (2) (2014) 319–342. [8] M. M. Nasr-Azadani and E. Meiburg, Turbidity currents interacting with three-dimensional seafloor topography, J. Fluid Mech 745 (2014) 409–443. [9] M. M. Nasr-Azadani, B. Hall, and E. Meiburg, Polydisperse turbidity currents propagating over complex topography: Comparison of experimental and depth-resolved simulation results, Comput. Geosci 53 (2013) 141–153. [10] M. M. Nasr-azadani, E. Meiburg, and B. Kneller, Mixing dynamics of turbidity currents interacting with complex seafloor topography, Environ. Fluid Mech 18 (1) (2016) 201-223. [11] N. Najafpour, 3D modeling of continuous dense current using large eddy simulation method, Master’s Thesis, Department of Mechanical Engineering, Sharif University of Technology, Tehran, 2012. (in Persian) [12] S. Abbaszadeh, Large Eddy Simulation of Continuous Density Current impinging on Obstacles, PhD Thesis, Department of Mechanical Engineering, Sharif University of Technology, Tehran 2014. (in Persian) [13] J. H. Francisco, E.P., Espath, L.F.R., and Silvestrini, Direct numerical simulation of bi-disperse particleladen gravity currents in the channel configuration, Appl. Math. Model 49 (2017) 739–752. [14] M. H. Garcia, Hydraulic jumps in sedimentdriven bottom currents, J. Hydraul. Eng 119 (1993)(10) 1094–1117. [15] C. D. Pierce, Progress-variable approach for largeeddy simulation of turbulent combustion, in Rep. TF-80, Mech. Eng. Department, Rep. TF-80, Mech. Eng. Dep. Stanford Univercity 2001. [16] S. K. Ooi, G. Constantinescu, and L. Weber, Numerical simulations of lock-exchange compositional gravity current, J. Fluid Mech 635 (2009) 361–388. [17] J. Kim, and P. Moin, Numerical investigation of turbulent channel flow, J. Fluid Mech 118 (1982) 341–377. [18] E Khavasi, M. Oshaghi, S. M. A. Mousavi, V. Zarei, M. Ghenaatpishe, B. Firoozabadi, and H. Afshin Experimental investigation of the effect of obstacle on turbidity currents, in Center of Excellence in Energy Conversion, School of Mechanical Engineering, Sharif University of Technology, Tehran, Iran 2012. [19] D. K. Lilly, A proposed modification of the Germano subgrid-scale closure method, Phys. Fluids A Fluid Dyn 4 (3) (1992) 633–635. [20] C. Härtel, E. Meiburg, and F. Necker, Analysis and direct numerical simulation of the flow at a gravitycurrent head. Part 1. Flow topology and front speed for slip and no-slip boundaries, J. Fluid Mech 418 (2000) 189–212. [21] C. Härtel, F. Carlsson, and M. Thunblom, Analysis and direct numerical simulation of the flow at a gravity-current head. Part 2. The lobe-and-cleft instability, J. Fluid Mech 418 (1) (2000) 213–229. [22] S. Venayagamoorthy, S. J. Koseff, J. Ferziger, and L. Shih, Testing of RANS turbulence models for stratified flows based on DNS data., DTIC Doc (2003) 127-138. [23] B. P. Leonard, A stable and accurate convective modelling procedure based on quadratic upstream interpolation, Comput. Methods Appl. Mech. Eng 19 (1) (1979) 59–98. [24] A. Peer, A., M. Dauhoo, and M. Bhuruth, A new fourth-order nonoscillatory central scheme for hyperbolic conservation laws, Appl. Numer. Math .886–476 )8002( )5( 85 [25] M. Garcia and G. Parker, Experiments on the Entrainment of Sediment into Suspension by a Dense Bottom Current, J. Geophys. Res 98 (3) (1993) 4793–4807. [26] M. H. Garcia, Depositional turbidity currents laden with poorly sorted sediment, J. Hydraul. Eng 120 (11) (1994) 1240–1263. [27] E. Khavasi, Experimental study of sediment behavior of the particle laden density current, Master’s Thesis, Department of Mechanical Engineering, Sharif University of Technology, Tehran 2009. (in Persian) [28] M. S. Altinakar, W. H. Graft, and E.J. Hopfinger, Flow Structure in Turbidity Current, J. Hydr. Res 34 (5) (1996) 713-718. | ||
|
آمار تعداد مشاهده مقاله: 827 تعداد دریافت فایل اصل مقاله: 1,092 |
||