کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
145637 456345 2016 11 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Prediction of fluid dynamic instabilities of low liquid height-to-tank diameter ratio stirred tanks
ترجمه فارسی عنوان
پیش بینی غیر قابل انعطاف پویایی مایع نسبت مخزن به مخزن مخلوط کم ارتفاع مایع به مخزن
کلمات کلیدی
شیار تصویری ذرات، مخلوط کردن، نسبت پر کردن، انتقال جریان، بی ثباتی سطح آزاد، پوسته پوسته شدن
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی مهندسی شیمی (عمومی)
چکیده انگلیسی


• Stirred tanks of unconventional geometry are widely adopted and poorly investigated.
• The relationship between flow field transition and free surface oscillation is found.
• The instability frequencies are identified by the FFT of the pressure time series.
• A novel interpretation of the instabilities’ origin is proposed.

In this work, original experimental data on the fluid flow instabilities associated with the oscillation of the liquid free surface in low liquid height-to-tank diameter ratio stirred tanks are presented. The local flow features of this type of tanks, which are commonly adopted as (bio)-reactors in important industrial productions such as drugs and bio-energy, are investigated by Particle Image Velocimetry. The local mean flow field and the turbulent characteristics are found to depend critically on the periodic variations of the liquid free surface, whose features vary as a function of the fill ratio. The frequency analysis of the dynamic pressure time series collected by a Pitot system shows that the frequency of the flow instabilities is mainly affected by the geometrical characteristics of the system. Therefore, the observed instabilities do not arise from the same origin of the so-called macro-instabilities previously identified in stirred vessels. A novel interpretation based on the liquid sloshing dynamics in cylindrical vessel is suggested.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Chemical Engineering Journal - Volume 295, 1 July 2016, Pages 336–346
نویسندگان
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