کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1537491 996588 2011 5 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Simultaneous measurements of multiple flow velocity components using frequency modulated lasers and a single molecular absorption cell
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد مواد الکترونیکی، نوری و مغناطیسی
پیش نمایش صفحه اول مقاله
Simultaneous measurements of multiple flow velocity components using frequency modulated lasers and a single molecular absorption cell
چکیده انگلیسی

Since unsteady, complex flow phenomena play an important role, optical measurements techniques are required for flow investigations, which provide simultaneous measurements of multiple velocity components. Doppler global velocimetry has this potential. It is a flow measurement technique, where the Doppler shift of scattered light is measured by a molecular absorption cell for frequency-to-intensity conversion. However, novel Doppler global velocimeters with laser frequency modulation were only used for single component measurements yet. In order to enhance such a system for the simultaneous measurement of multiple components, a concept based on frequency division multiplexing is introduced for the first time. Besides multiple lasers, only a single molecular absorption cell and a single detector unit is required. Two-component measurements of velocity profiles from nozzle flows are presented as a proof of principle. The designed measurement system provides high measurement rates of up to 20 kHz, which is three orders of magnitude higher than for typical Doppler global velocimetry setups.

Research Highlights
► We describe an optical flow measurement system using laser frequency modulation.
► A frequency multiplexing technique is introduced for overlaying three light signals.
► As a result, all three velocity components are measured simultaneously.
► The built measurement system provides high measurement rates in the kilohertz range.
► This allows to analyze complex turbulent and non-stationary flows.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Optics Communications - Volume 284, Issue 12, 1 June 2011, Pages 3060–3064
نویسندگان
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