بررسی جریان غیرخطی در شکستگی های سنگی با دیواره زبر

نوع مقاله : مقاله پژوهشی

نویسندگان

1 نویسنده مسئول و استادیار دانشگاه صنعتی امیرکبیر

2 دانشجوی کارشناسی ارشد دانشگاه صنعتی امیرکبیر

3 دانشیار دانشگاه صنعتی امیرکبیر

چکیده

در بسیاری از ساختارهای زمین شناسی، نفوذپذیری ماتریکس سنگ در مقایسه با شکستگی های توده سنگ ناچیز است و شکستگی ها مسیر اصلی جریان سیال در توده سنگ هستند. رفتار جریان سیال درون شکستگی به دلیل افزایش کارایی مطالعات طراحی، اجرا و ایمنی سازه های زیرزمینی و روباز به عنوان یک موضوع مهم تحقیقاتی تلقی می شود. در این مقاله، جریان سیال یک فازی درون شکستگی های سنگی مطالعه شده است. دامنه محاسباتی یک شکستگی فرضی سه بعدی تولید شده و شبیه سازی جریان آرام و آشفته برای دامنه گسترده ای از سرعت های ورودی جریان و با استفاده از روش حجم محدود انجام شده است. افت فشار در بین مقاطع قائم متوالی در داخل شکستگی محاسبه شده و برای توصیف ارتباط بین دبی و افت فشار ناشی از جریان سیال استفاده شده است. نتایج شبیه سازی نشان می­دهد که: (1) افت فشار استاتیک پیش بینی شده با شبیه سازی جریان آشفته برای محدوده عدد رینولدز 5/4 تا 5/89 به ترتیب  %3 تا %17 بیشتر از مقادیر پیش بینی شده با شبیه سازی جریان آرام است؛ (2) قانون فورچی میر به خوبی با نتایج شبیه سازی جریان مطابقت دارد و رینولدز بحرانی 15 برای جریان غیر خطی پیشنهاد شده است.

کلیدواژه‌ها


عنوان مقاله [English]

Evaluation of Non-linear Fluid Flow Through Rough-walled Fractures

نویسندگان [English]

  • Mostafa Sharifzadeh 1
  • Morteza Javadi 2
  • Korosh Shahriar 3
چکیده [English]

In many geological structures, the matrix permeability is negligible and the fractures are the main flow paths. The fluid flow and particle transport through rock fracture are increasingly important research topics mainly to the demands for design, operation and safety assessments of underground/ surface constructions. In this paper, single-phase fluid flow through a rock fracture is studied. Computational domain for an artificial three-dimensional fracture is generated and used for numerical fluid flow simulations. Both laminar and turbulent flow simulations are performed by using finite element method for a wide range of inlet velocities. The calculated average pressure drops, between consecutive vertical sections are compared to describe the flow rate dependant pressure drop. The simulations results show that; (i) the predicted static pressure drop for turbulent flow simulation was roughly 3% to 17% more than laminar simulation at Reynolds number of 4.5 to 89.5, respectively, and (ii) the Forchheimer law is fitted very well to flow simulation results and critical Reynolds number of 15 is suggested.

کلیدواژه‌ها [English]

  • Non-linear fluid flow
  • Fluid flow simulation
  • Turbulent and laminar flow
  • Forchheimer law
  • Rock fractures
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