Technical Specifications

Specifications

• Compact, free-standing open-circuit suction subsonic wind tunnel with a working section of 300~310 mm by 300~310 mm and 600~620 mm long
• Air velocity: 0 to 36 m/s
• Air enter the tunnel through an aerodynamically designed effuser (cone) that accelerates the air linearly
• It then enters the working section and pass through a grille before moving through a diffuser and then to a variable speed axial fan
• The grille protects the fan from damage by loose objects

The air leaves the fan, pass through a silencer unit and then back out to the atmosphere

• A separate control and instrumentation unit controls the speed of the axial fan (and the air velocity in the working section)
• The control and instrumentation unit includes manometers and electrical outlets to supply electrical power to other instruments.
• A metal frame supports the wind tunnel
• The frame includes lockable castors for convenient mobility
• The working section of the tunnel is a square section with a clear roof, sides and floor
• The sides are removable and the floor and each side panel have a special position to support the wind tunnel models
• Supplied with the wind tunnel are a protractor and a model holder to support and accurately adjust the angle of models fitted
• Two traversing probes are fitted on the working section
• One is a Pitot-static tube and the other is a standard Pitot tube
• They fit upstream and downstream of the models and connect to the manometers on the instrumentation unit to show pressure
• The model holder supplied to hold a model
• It is designed to hold a shaft of diameter 11.95 ±0.015 mm (diameter) and 215 ±1.25 mm (length) mounting stem
• The protractor fits on to the shaft of a model when a Balance is not being used
• It can be used when setting up models and rotating them during experiments

Three Component Balance Module AT002/01:

• The Three-Component Balance fits onto the working section of the above Subsonic Wind Tunnel
• Provides an easy-to-use support system for wind tunnel models
• It measures lift, drag and pitching moment exerted on the model
• The balance comprises a mounting plate secured to the wind tunnel working section
• A triangular force plate is held on the mounting plate by a mechanism that constrains it to move in a plane parallel to the mounting plate only, while leaving it free to rotate about a horizontal axis
• This arrangement provides the necessary three degrees of freedom
• The forces acting on the model are transmitted by cables to three strain gauged load cells
• The output from each load cell is taken via an amplifier to a display module
• The display module is mounted onto the wind tunnel control and instrumentation frame and includes a digital display to show the lift, drag and pitching moment directly
• The equipment should be fully compatible with ‘Sci-Cal’ Data Acquisition System and can quickly and conveniently connect to the frame-mounted interface unit
• The model support of the balance can be rotated by 360 degrees
• This allows adjustment of the angle of incidence of the model to the direction of air flow
• The model support can be locked in the required position by a simple clamp after adjustment

Balance Angle Feedback Unit Module AT002/02:

• The Balance Angle Feedback Unit to be used with the Three- Component Balance to measure the angular position of models mounted on the balance in the wind tunnel
• Mountable on the Three-Component Balance attached to the wind tunnel
• Transmits the rotational angle of the model to data acquisition system
• The angle of the model can be logged on a suitable computer along with the other captured experimental data

Differential Pressure Unit (2 Nos.) Module AT002/03:

• The Differential Pressure Transducer and readout measures and display pressures in Pitot-static tubes and other pressure-sensing devices fitted to a wind tunnel, with respect to the atmosphere or differential pressures
• The control and instrumentation panel includes a location for mounting up to two Differential Pressure Transducer modules
• Each module contains a calibrated pressure transducer
• The unit has an integral liquid crystal display that allows the user to read pressure directly
• The signals of the pressure sensors can be output to Data Acquisition System
• When the Differential Pressure Transducer is used with the automatic data acquisition unit provides a significant advantage over conventional instruments such as manometers.

16 to 32-Way Pressure Display Unit Module AT002/04 (to be advised):

• The 16 to 32-Way Pressure Display Unit measures and display up to 16 to 32 different pressures from models and other measuring instruments fitted to a wind tunnel
• It ideally suites in applications where multiple pressure measurements are required, for example in tapped aerofoil model investigations
• The unit is mounted onto the control and instrumentation frame of the wind tunnel
• The unit contains between 16 to 32 calibrated pressure transducers
• Input connection to each are via quick-release pressure inputs mounted on the front panel of the unit
• This allows easy and quick connection between the unit and an experiment mounted in a wind tunnel
• All pressures are measurable with respect to atmosphere
• The unit has an integral liquid crystal display with a scroll switch that allows all channels to be viewed in groups of four at any time
• The conditioned outputs of the pressure sensors can be output to ‘Sci-Cal’ Data Acquisition System
• When the 16 to 32- Way Pressure Display Unit is used with the system it allows laboratory time to be used more efficiently because data can be captured and processed much more quickly than when using manual techniques
• The facility in the software to average data to remove the fluctuations inherent in wind tunnel measurements, enhances the quality of the results by making their interpretation much easier

Pitot Static Traverse Module AT002/05:

• A Pitot-static tube that is mounted in the working section of the wind tunnel, either upstream of the position of the test model or on the fore-aft traverse
• This allows students to do ‘wake’ traverses, of a model
• The vertical position of the tube, which is adjustable, displays on a digital indicator
• The digital indicator position can be set to zero in any position
• The position of the Pitot-static Traverse to be output to data acquisition system unit to allows computer-based data acquisition and display

Technical Specifications

• Dimensions (Assembled): L x W x H: 3 m x 1 m x1.2 m
• Working section: 300 mm x 300 mm, and 600 mm long, Made in Plexi-glass
• Air velocity: 0 to 36 m/s
• Fan:

• Type: Axial Fan,
• Rated Air Flow: Upto 11,000 m3/hr

• Fan Motor:

• Capacity 3 hp,
• Speed: 1440 / 2800 RPM
• Make: Siemens / ABB

• Variable Speed Drive:

• Type: Micro-processor Based VFD
• Capacity 3 hp
• Supply Voltage: 380 – 440 V AC, Three Phase
• Make: Delta / ABB

• Air Flow Measurement by Pitot Tube & Manometer
• 16 Tube, Inclined Manometer (AF-02.01)
• Three Component Force Balance for Lift, Drag & Pitch Measurement with digital indicator
• Cylinder model for pressure measurement
• NACA 2412 Aerofoil for Drag Measurement
• NACA 0012 Aerofoil with Pressure Tappings
• Three Dimensional Drag Models
• 12 Chanel Electronic Manometer Bank

• Measures up to 12 different pressures from models
• All pressures are measured with respect to atmosphere
• Range 0-300 mm of H₂O
• Angle Feedback Unit
• Pitot Traverse Mechanism
• Data Acquisition System and Software:
• USB Based Multi-Functional Data Acquisition Device
• 16 to 32 Analog inputs (16-bit, 250 kS/s)
• 2 Analog outputs (16-bit, 250 kS/s);
• 4 digital I/O
• Make: National Instruments, USA
• Lab view based customized programmed software and Data processing:

LabVIEW based software with Graphical & Numerical displays for parameters measured by

different sensors.

The software enables user to control the air speed from computer.

Following measured parameters are displayed on screen during experimentation –

• Air Velocity
• Pressure Distribution around different models
• Lift & Drag Forces
• Angle of Attack
• The software analyses experimental data & performs calculations.
• Experimental test results are displayed in tabular format along with relevant graphs.
• The measured parameters, test results can be exported in to Excel format or Printed using any printer connected to computer / laptop.

Experiments

• Flow past bodies with pressure and velocity observations in the wake
• Performance of an aerofoil
• Pressure distribution around a cylinder
• Study of the characteristics of models involving basic measurement of lift and drag forces
• Study of the pressure distribution around an aerofoil model to derive the lift and comparison with direct measurement of lift
• Drag force on a body normal to an air flow
• Determine drag and lift coefficients for different models (Aerofoil and Flat plate)

Optional Accessories

• Data Acquisition System
• Three-Component Balance
• Angle Feedback Unit
• 16 Way Digital Pressure Display Unit
• Smoke Generator