SOLUTION SHEET

StreamLine Pro CTA system
Research grade hotwire anemometer for
turbulence investigations

High performance anemometer system for the most demandingapplications
The Dantec Dynamics StreamLine Pro system is the next generation CTA based on
the popular StreamLine system. Using the latest developments in signal processing
technology, the StreamLine Pro provides the highest Signal-to-Noise Ratio andwidest bandwidths of any commercially available CTA system. Some of the additional
improvements in this new design include higher accuracy of gain and offset settings,
and new software features running on the latest Windows OS. For fundamental fluid
dynamics and turbulence research, these significant improvements are critical tosuccessful results especially in the most challenging measurement applications.

Key benefits•

High temporal resolution: Fluctuations up to 450 kHz can be measured•

High spatial resolution: Eddies down to fractions of a mm can be resolved•High dynamic range: from a few cm/s to supersonic•

Real-time continuous output signal: Provides full information in the entire
frequency range•

Application software supports set-up, automatic calibration, data acquisition anddata reduction•Turbulence statistics in both amplitude and frequency domain based on velocity
time series

The StreamLine Pro solution in brief
Constant Temperature Anemometer (CTA) technology is a well-establishedtechnique for the measurement of velocity in gas and liquid flows. The
measurement principle uses King’s law and the cooling rate of small, heatedsensors placed in the flow. As the name suggests, the sensor temperature
is kept constant and using a Wheatstone bridge. The output voltage fromthe anemometer is digitized and converted to velocity based on the probecalibration. Even though CTA technique is intrusive it is still the only solution
for high frequency turbulence investigations, i.e. the accurate determinationof high frequency flow fluctuations, boundary layer diagnostics,
simultaneous multi-point velocity and temperature measurements.

A typical StreamLine Pro configuration.

Using the StreamLine Pro CTA system is made easy with our StreamWare
Pro software. This comprehensive software package interfaces with theelectronics to set the probe overheat, automatically balances the bridge,
provides data acquisition, and data analysis of the results. The system
combines the advantages of the high quality hot-wire anemometer,high accuracy A/D converters and graphical user interface. The systemcomprises:•Frame with controller and temperature monitor•

CTA anemometer modules•

Temperature modules•

Automatic velocity calibrator•

Automataic temperature calibrator•

Hotwire and fiber-film probes with supports•

Analog to digital converters•

StreamWare Pro application software
Frame with controller and three temperature modules and three velocity
channels

System components
Frame with controller
The StreamLine Pro frame contains 6 power supplies, a controller and slots for
6 modules (CTA or temperature modules). Six frames can be combined in one
CTA measurement system allowing for up to 3-6 simultaneous measurement
channels.
The CTA modules are state-of-the art electronics containing three bridge
configurations, two 1:20 bridge ratios with 20 ohms and 10 ohms top
resistors, and one 1:1 bridge ratio, selectable from the software. The 1:1
configuration is useful especially in situations where high bandwidths andlonger cables are required.

Automatic Calibrator

As the sensor response depends on velocity, a calibration is required foraccurate CTA measurements. The StreamLine Pro Automatic Calibrator can
provide in situ air velocity calibrations to assure high accuracy.
The StreamLine Pro Automatic Calibrator is designed for velocity calibration ofwire and fiber-film probes in air at velocities from a few cm/s up to > 300 m/s.
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Automatic Velocity Calibrator

The probe is placed in a free jet with a flat, low-turbulent velocity profile
during calibration. The calibrator is connected to a computer via USB orEthernet and the calibration process is controlled from StreamWare Pro.
The velocity calibrator is delivered with a certificate including the calibration
data of the internal transducers (traceable to accredited laboratories) and averification of the jet velocity in three points over the velocity range.
For measurements in water, a water calibration system is also available.

Automatic Directional Calibrator

Hot-wire sensors have velocity, temperature and directional sensitivity.
Multiple sensor probes are used to perform 2- and 3- component velocity
measurements using information about the directional sensitivity.
Although it is possible to use typical (default) k and h factors for thecalculation of angular velocity, for the most accurate measurement,directional as well as magnitude calibration is required. We offer botha manual as well as high precision automatic (motorized) directional
calibration modules.
During the directional calibration, the probe is yawed and rolled around
two axes, while it is exposed to a constant velocity. Measuring the probe
response with the actual velocity on each sensor, StreamWare Pro
software calculates the pitch and yaw factors for each individual probe.
This calibration is stored in the software and is automatically referenced
during data reduction.

Automatic Directional Calibrator allows
probe rotation around two axes.

Completing the measuring chain - probes
Dantec Dynamics hot-wire and hot-film probes cover most applications inflow measurements. Additionally, special probe and support designs forunique flow situations in accordance with customer’s specifications canbe offered upon request. Examples of these include; 2-D/3-D probes withtemperature sensor, 4-wire vorticity probes, extended length probe supports,
2-D high temperature probes, and more. Please contact your Dantec
Dynamics representative and refer to the probe catalog for more details.
Hot-wire and hot-film probes

SoftwareStreamWare Pro is a complete software package for Windows environmentthat helps the user to design, organize and document the measurements
as well as post process the results. The complete system can be controlled
by StreamWare Pro, which performs hardware set-up, automatic probe
calibration, data acquisition, conversion and reduction. Raw and reduced
data can be presented in StreamWare Pro or they can be exported to otherapplications (e.g. Excel and Tecplot®) for further analysis.

Turbulence spectrum downstream of acylinder in cross flow.

Turbulence Diagnostics in StreamWare Pro
CTA is the preferred technique for investigation of turbulence due to its
unmatched frequency response. In the frequency domain, power spectra
can be computed for analysis of the fluctuating flow characteristics.

Data export and presentation
Based on time series acquired in one or several points in the flow statistics,
mean velocity, turbulence intensity, Reynolds stresses and autocorrelation
function can be calculated and displayed. Results can be displayed on
StreamWare Pro or exported to other applications for further analysis or foradvanced graphical presentation.
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3D plot of velocity profile of a round jetOptions
Temperature module for temperature fluctuations
An optional temperature module is available for measurement of fast
temperature fluctuations with wire probes of diameters down to 1 µm. It
delivers a constant current adjustable between 0.1 and 5 mA through thewire and offsets, amplifies and filters the output voltage, which is a linear
function of the flow temperature. The output is acquired by StreamLine Pro
and can be analyzed individually or correlated with velocity fluctuations
measured with an ordinary hot-wire. For temperature measurements, atemperature calibration system is also available.

Traversing systems
Dantec Dynamics offers traversing systems that can move the probe in one,
two or three directions with micrometer accuracy.

Probe Rotation Unit
A motorized probe rotation unit is available which can also be mounted ona standard traverse mechanism. The accurate rotation is useful to obtainproper alignment of the probe with respect to the flow, or for obtaining twoor three velocity components (non-simultaneously) from single slanted wireprobe.

System Computer
The StreamLine Pro CTA system can be delivered with a system computer,which is preconfigured, tested and ready to use. All necessary hardware
and software installation is performed before delivery.
All Dantec Dynamics systems with system computer have to pass a detailed
system test procedure before shipment where test data is recorded on thesystem computer. The system test procedure ensures a smooth installationof the system on site and a quick start to actual research activities.

Technical specifications
Specifications			

StreamLine Pro

Number of modules		Max. 6 per frame

Number of frames			Max. 3 per system

Number of channels		Max. 16 per system

Max. Frequency response		

450kHz (1:1 bridge, dedicated HF probe)

Equivalent Input Noise		

Typical 1.8 nV/√Hz

Equivalent Input Drift		

Typical 0.3 µV/°C

Communications			

USB 2.0 and 10/100 Mbit LANDimensions			

45 cm x 18.5 cm x 46.5 cm

Solution Sheet SS_0566_v3. Subject to change without notice. Copyright © 2024.
Dantec Dynamics. All Rights Reserved. www.dantecdynamics.com

Three-axis traversing system.