شبیه سازی رفتار هیدرودینامیکی یک قطره رسانا در حضور میدان الکتریکی

نوع مقاله : مقاله پژوهشی

نویسندگان

دانشکده مهندسی، دانشگاه یاسوج، یاسوج، ایران

چکیده

در این تحقیق، اثر میدان الکتریکی روی تغییر شکل و تغییر فاز یک قطره کاملا رسانای معلق در یک سیال عایق بررسی می‌شود. معادلات اساسی، معادلات جریان و انرژی در حالت تراکم ناپذیر می‌باشند. اثر میدان الکتریکی به صورت تنش‌های نرمال در سطح مشترک ظاهر می‌شود که باید هنگام حل معادلات جریان اعمال شوند. از روش سطح تراز برای ردیابی سطح مشترک استفاده می‌شود. ناپیوستگی های موجود در سطح مشترک با استفاده از روش سیال مجازی اعمال می‌گردند. ابتدا تاثیر میدان الکتریکی روی هیدرودینامیک قطره مطالعه می‌شود. تطابق خوبی بین نتایج شبیه سازی و نتایج آزمایشگاهی مشاهده می‌گردد.. در اثر تنش‌های الکتریکی، قطره دچار تغییر شکل شده و در جهت میدان کشیده می‌شود. با افزایش عدد مویینگی الکتریکی، تغییرشکل قطره افزایش می‌یابد. اگر عدد مویینگی الکتریکی از حد بحرانی فراتر رود، تغییر شکل قطره ناپایا خواهد بود. نوآوری تحقیق حاضر مربوط به مطالعه اثر میدان الکتریکی روی تبخیر قطره می‌باشد. بر اساس نتایج حاصل، نرخ تبخیر قطره در حضور میدان الکتریکی افزایش می‌یابد. در صورتی که عدد مویینگی الکتریکی از حد معینی )عدد مویینگی الکتریکی بحرانی تبخیر( تجاوز کند، تبخیر قطره به میزان قابل توجهی افزایش می‌یابد. این مقدار بحرانی برای اولین بار در این تحقیق معرفی می‌شود.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Simulation of Hydrodynamic Behavior of a Conductive Drop Under an Electric Field

نویسندگان [English]

  • H. Nazari
  • P. Pournaderi
Department of Engineering, Yasouj University, Yasouj, Iran
چکیده [English]

In this research , the effect of an electric field on the deformation and phase change ofa perfect conductive drop suspended in a perfect dielectric fluid is studied . Basic equations are theincompressible flow and energy equations . Electric field effect appears as normal stresses at interfacewhich are taken into account in solving flow equations . The level-set method is used for interfacetracking. Discontinuities at interface are imposed using the ghost fluid method. In the first step , the effectof an electric field on the hydrodynamic of a drop is studied . A good agreement between the simulationand experimental results is observed. Due to electric stresses , drop deforms in the direction of electricfield . The drop deformation increases with the electric capillary number. If the electric capillary numberexceeds the critical value, deformation will be unsteady. Novelty of this research is related to the studyof electric field effect on the drop evaporation. Based on the results, drop evaporation rate is enhancedin the presence of an electric field . If the electric capillary number exceeds a specific value (evaporationcritical electric capillary number) , drop evaporation will increase considerably . This critical value isintroduced in this research, for the first time.

کلیدواژه‌ها [English]

  • Level set Method
  • electric field
  • Drop deformation
  • Phase change
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