کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
7052239 1457408 2015 29 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Experimental study of transient behaviour of laminar flow in zigzag semi-circular microchannels
ترجمه فارسی عنوان
بررسی تجربی رفتار گذرا جریان لمینار در میکرو کانال نیمه دایره ای زیگزاگ
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی جریان سیال و فرایندهای انتقال
چکیده انگلیسی
An experimental investigation is carried out to understand the hydrodynamics of single-phase water flow in a zigzag microchannel with a semi-circular cross-section (diameter 2 mm). The present study covers Reynolds numbers in the laminar regime, under both steady and transient conditions. Time-resolved velocity measurements were made using high-speed micro-PIV techniques. The influence of inlet unsteadiness on flow characteristics is investigated. Through time-resolved velocity measurements, a transition from a steady flow to a time-dependent oscillatory flow having a few dominant frequencies and subsequently to a complex transient flow is observed in the wavy channel. However, the transition to a transient flow occurs at much lower Reynolds numbers (Rec ∼ 215) than predicted numerically. The early transition is believed to be triggered by small inlet flow disturbances in the experiments, since the flow is very sensitive to the inlet conditions at sufficiently high Reynolds numbers. This hypothesis is supported by results from transient CFD simulations with fluctuating inlet boundary conditions.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Experimental Thermal and Fluid Science - Volume 68, November 2015, Pages 644-651
نویسندگان
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