مهندسی مکانیک مدرس

مهندسی مکانیک مدرس

بررسی آزمایشگاهی دقت سرعت‌سنج صوتی جانب‌نگر در میدان جریان آشفته

نویسندگان
1 دانشجوی دکتری، دانشگاه تربیت مدرس (دانشکده عمران و محیط زیست)
2 دانشگاه تربیت مدرس (دانشکده عمران و محیط زیست)
3 دانشگاه صنعتی امیرکبیر
4 دانشگاه بین المللی قزوین (دانشکده عمران و محیط زیست)
5 دانشگاه تربیت مدرس، تهران، ایران
چکیده
از جمله روش‌های پرکاربرد اندازه‌گیری میدان جریان در کانال‌های باز استفاده از دستگاه سرعت سنج صوتی داپلر می‌باشد. حضور شاخک‌ها و بدنه دستگاه سرعت سنج صوتی در داخل جریان موجب تغییر الگو و ساختار آشفتگی جریان می‌شود. بنابراین خطای دستگاه سرعت سنج صوتی داپلر ناشی از دو عامل خطای ذاتی دستگاه و حضور بدنه و شاخک‌های دستگاه در داخل جریان می‌باشد. برای فهم بهتر این موضوع، در این مقاله میدان جریان با استفاده از ابزار سرعت‌سنجی تصویری ذرات و دستگاه سرعت‌سنج صوتی جانب‌نگر اندازه‌گیری شد. نتایج حاصله نشان داد که در اندازه‌گیری سرعت طولی، نتایج هر دو ابزار به یکدیگر نزدیک بوده و به‌طور متوسط 5 درصد اختلاف دارند، در حالی که سرعت‌های قائم و عرضی دارای تفاوت قابل توجهی با یکدیگر می‌باشند. همچنین مقایسه مقادیر شدت آشفتگی طولی و عرضی و تنش برشی رینولدز نشان می‌دهد که اختلاف مقادیر در نزدیکی سطح آب کمتر و با نزدیک‌شدن به بستر افزایش می‌یابد.
کلیدواژه‌ها

عنوان مقاله English

Experimental study of side looking ADV probe accuracy in a turbulent flow field

نویسندگان English

mostafa nabipour 1
ali akbar salehi neyshabouri 2
Reza Sadeghi Dodaran 2
Amir reza zarrati 3
Hossein Mohajeri 4
Mohammad Zabetian 5
1 ph.d student
2 Professor, Tarbiat Modares University
3 professor, amir kabir university
4 Assistant Professor, ٍEmam khomeini international University
5 Assistant Professor, Tarbiat Modares University
چکیده English

One of the practical and useful techniques for the flow field measurement in open channels is Acoustic Doppler Velocimeter (ADV). Presence of ADV probe and its holding system against flow disturb natural flow pattern which can change turbulent flow structure. Thus, the error of the Acoustic Doppler Velocimeter is consist of its intrinsic error and the presence of ADV against flow. To have better understating about this effect, in this paper, flow field in an open-channel is measured using Particle Image Velocimetry (PIV) technique and side-looking ADV probe. The results show that sreamwise velocity obtained from both methods are in good agreement and on average, there is 5 percent difference, while vertical and lateral components of velocity are considerably different. Also, comparison of sreamwise and lateral turbulence intensities and the Reynolds shear stress shows lower differences for measured points near the water surface and the differences increase approaching to the bed.

کلیدواژه‌ها English

Side looking Acoustic Doppler Velocimeter
Particle Image Velocimetry
Flow pattern
Turbulence parameters
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