Wind Tunnel Lab

Two Dimensional Wind Tunnel

The test section can be fitted with two interchangeable variable incidence model carriers, one with a cylindrical section and the other with a low velocity sub-sonic aerofoil. The cylinder has a single static tapping which can be used to plot the pressure profile around the cylinder. Two Dimensional Wind Tunnel is designed for use with either Air Flow Bench or Fan Test Stand. The wind tunnel has a high aspect ratio clear acrylic test section 250 mm high and 65 mm deep. Pressures can be measured using Multitube Manometer or the Multiple Pressure transducer Module which provides 0-10 Volt analogue outputs for connection to a computer or data logging system. The aerofoil has 14 static pressure tappings allowing the pressure profile around the nose and along both the upper and lower cambered surfaces to be measured.

Experimental Capability:
Pressure profile around an aerofoil section and derivation of lift and drag forces and coefficients  
Pressure profile around a transverse cylinder and derivation of drag force coefficient  
Variation of lift and drag forces and coefficients, and liftdrag ratio with aerofoil incidence
Direct measurement of lift and drag on an aerofoil
Direct measurement of drag on a transverse cylinder.

Two Component Balance

Adjustable balance weights allow easy initial setup and zeroing of the system. Two component balance features a simple unique lever system employing vertical and horizontal balance beams to provide independent measurement of lift and drag forces using precision spring balances. 

Experimental Capability:
Lift and Drag coefficients and Lift Drag ratio
Lift and Drag Force by direct measurement  

Features:
Accurate force measurement provided by two precision spring balances  
Adjustable balance weights for initial set-up  
Independent measurement of lift and drag by unique vertical and horizontal balance beams  
Optional analogue load cells providing 0 to 10 Volt output.

Pressure Cylinder

Mounts vertically and spans the test section of an Educational Wind Tunnel
Angular position is adjustable
Comes with ample tubing
24 flush-mounted pressure taps around its circumference
Outside diameter of 4 inches (10.16 cm).

Water Tunnels And Channels

Top Speed:
Demonstrated - 60 ft/sec (18.3 m/s)
Nominally - 30 ft/sec (9.1 m/s)

Model Positioning System

Trans/supersonic systems:
Nominal pitch angle range: <10 degrees + / <5 degrees.
Subsonic systems:
Nominal yaw angle range: +/- 30 degrees typical
Nominal pitch angle range: +/- 30 degrees typical

Yaw Probe

Featured machined aluminum triangle that shows the orientation of the ports from outside the test Section and acts as a handle
Three ports
Mounts easily in the test section of an Educational Wind Tunnel
Length of 10.5 inches (26.7cm)
Outside diameter (O.D.) of 0.125 inches (3.175mm)
Comes with ample tubing.

Traverse Systems

Sweep area - based on each unique test section and application
Position accuracy - customer defined.

Optional Features:
Models and Probes
Data Acquisition and Control (DAC) System.

Pressure Wing

18 Flush-mounted pressure taps around its Clark Y-14 airfoil
Angular position is adjustable
Mounts vertically and spans the test section of an Educational Wind Tunnel (12 inches / 30.48cm)
Comes with ample tubing
Pressure Wing has a chord of 3.5 inches (8.9cm).

Pitot Static Probe

Features a rounded-tip total-pressure tap
Reaches 2.6 inches (6.6cm) forward of the bend
Has an OD of 0.125 inches (3.175mm)
6 static ports
Extends 13 inches (33cm) to the bend
Comes with ample tubing.

Flat Plate And Mouse

Demonstrate and study boundary layers and boundary layer growth with ease. The pressure probes ascend on an angle covering a width of one inch (25.4mm) and a height of 0.24 inches (6.1mm). The probes are approximately 0.048 inches (1.22mm) apart along the diagonal. The Flat Plate And Mouse combination has a 10-tap total pressure probe, or mouse, that can be positioned in three locations along the length of the flat plate.

Flow Visualisation Wind Tunnel

Ideal for small group experiments or classroom demonstrations, the apparatus is floor standing. A variablespeed fan mounted on top of the wind tunnel produces the air flow through the working section. Air flow is vertically upwards. A vertical, suction-type wind tunnel with smoke visualisation. Allows demonstrations and student investigations into the flow of air around a wide variety of differently shaped models. Smoke is produced by the vapourisation of a high-quality food grade oil. A filter helps provide uniform air flow. A smoke generator connects to a comb mounted in the wind tunnel below the working section. Students can move the comb from side to side to aid investigations into the aerodynamic properties of a test model.

Experiments:
When used with the optional models, the visualisation and demonstration of:
Separation
Rotational flow
Boundary layers

Pyramidal Balance

Pyramidal Balance can be divided into two main groups: internal and external. The group names are derived from their location relative to the test model and wind tunnel test section internal balances reside inside a test model, while external balances reside outside the test section. During the early years of wind tunnel testing, Forces and Moments were literally measured through pan-type balances. Although technology has advanced dramatically since those early days, the term balance is still applied to the devices used for Force and Moment measurements today.

Sting Balance

Balances can be divided into two main groups: internal and external. The group names are derived from their location relative to the test model and wind tunnel test section internal balances reside inside a test model, while external balances reside outside the test section. During the early years of wind tunnel testing, Forces and Moments were literally measured through pan-type balances. Internal Force/Moment balances are almost universally used for measurements in supersonic and transonic tunnels. However, they are also becoming popular in subsonic tunnels. Although technology has advanced dramatically since those early days, the term balance is still applied to the devices used for Force and Moment measurements today.

Educational Wind Tunnel

The Complete Educational Wind Tunnel System is an easy-to-use, all-in-one fluids aerodynamics laboratory. Optional features include instrumentation, data acquisition, models and probes. Educational Wind Tunnel (EWT) System is a powerful tool for educators and researchers alike. With many optional features available, the budget-conscious user can start with a basic system and upgrade as needs change or funding becomes available. Perfectly scaled for high school or university use, the basic Educational Wind Tunnel system is also popular with small technical businesses needing an accurate, reliable testing device.

Schlieren Systems

In supersonic flow, air experiences very large changes in density as it approaches, passes through and trails shock waves. As the density of air changes, so does its index of refraction. Schlieren Systems let you see shock waves as a combination of bright and dark areas. In the study of supersonic flow, shock and expansion waves are used to determine Mach number. Schlieren are optical in homogeneities in transparent materials. In most situations, however, they are virtually invisible to the naked eye.

Closed Circuit Wind Tunnels

Most Closed Circuit Wind Tunnels designs are traditional single-return, horizontally arranged circuits. However, any configuration is possible. As with all wind tunnels, exceptionally steady test section flow with close uniformity of velocity is standard. The use of steel for construction offers complete design freedom to meet your unique specifications and needs, such as low overhead clearance or building support columns. Turbulence level is typically below 0.10 percent throughout the full tunnel speed range.

Blow Down Wind Tunnels

Blow Down Wind Tunnels are a special type of Open Circuit wind tunnel. For Blow Down Wind Tunnels, however, air is blown down into the wind tunnel by a fan located upstream of the test section, as the name implies. Compared to standard Open Circuit wind tunnel configuration, blow-down style tunnels provide an extra degree of testing flexibility. For most Open Circuit tunnels, fan assemblies are located downstream of the test section and air is drawn through the wind tunnel with suction. Most commonly, these tunnels are used for tests requiring liquid or particulate injection. All blow-down style tunnels have custom test sections, and many are requested to include built-in test article mounting arrangements. Because all tunnels are made to fit the customers needs, there is no limitation to the options available.

Transonic Wind Tunnels

Employing variable test section porosity, computer-controlled valves, chokes and flaps, target airspeeds are easy to achieve and maintain. Using compressed air Transonic Wind Tunnels offer running speeds of M=0.3 to M=1.3. Systems with test section sizes of 8-inch x 8-inch (20.32cm x 20.32cm) and 20-inch x 20-inch (51cm x 51cm) are available.

Supersonic Wind Tunnel

Supersonic flow and the occurring shock waves can be directly observed with the supplied Schlieren optic apparatus. The continuous operation can allow enough time to take measurements and to observe the phenomena. This an open, continuously operating supersonic wind tunnel with a rectangular measuring section. Transonic and supersonic flows from Mach 0.8 up to Mach 1.8 can be realized with interchangeable measuring sections and nozzle profiles. The tunnel is driven by a vacuum pump (included). The pump is effectively silenced so it can be placed in the same room as the wind tunnel. Four aerofoil models are supplied: a wedge, a double wedge, a bullet and a rocket. A flow straightener at the inlet ensures a low degree of turbulence.

Fan Test Stand

The centrifugal fan which has a low chord impeller and split volute diffuser casing is directly driven by a DC dynamometer giving a variable speed from 0-4000 rpm, with a swinging stator providing load cell torque measurement and equipped with a toothed wheel for speed measurement. The bench consists of a welded steel frame mounted on castors providing two work surfaces for experiments together with ample storage space for experimental apparatus when not in use. The working surfaces accommodate a control console and a centrifugal fan with variable speed dynamometer drive, to which can be coupled a series of inlet and outlet ducts. The control console houses all electrical components and circuitry associated with the power and speed control, while the instrument panel includes: START/STOP pushbuttons, speed control knob and torque, speed, armature voltage and current displays. The ductwork supplied with the bench is manufactured in aluminium sections assembled by deep spigoted sockets, sealed by O rings. It includes a venturi nozzle, a bell mouthed inlet, flow straighteners, pressure tapping points and disc valves and is designed to allow assembly to various configurations by means of quick release toggle latches. A dual multi-slope manometer scaled 0- 5 and 0-2.5 kPa is supplied for use with the air flow nozzle.

Boundary Layer Experiment

Boundary layer studies involve the determination of the thickness of this layer and the velocity profile within it. These parameters will vary with velocity of the fluid flowing over the surface, the distance from the leading edge of the surface and the degree of roughness of the surface. When a fluid flows adjacent to a stationary surface, e.g. down a tube, the fluid immediately in contact with the stationary surface will have zero velocity. The resulting shear forces in this area will be significant and lead to high values of drag forces between the flowing and stationary surface. As a result there will be a comparatively steep velocity gradient associated with the adjacent boundary layer of the fluid. Boundary Layer Experiment accommodates these studies.

Experimental Capability:
Boundary layer growth on smooth and rough surfaces
To determine the velocity profile of the boundary layer at different distances from the sharp leading edge of a smooth test plate
To determine the velocity profile of the boundary layer at specified distances from the blunt leading edge of a smooth test plate

Subsonic Open Circuit Wind Tunnel

Air enters the test section through a carefully designed contraction followed by an aluminum honeycomb flow straightener designed to ensure that the flow is steady in both magnitude and direction and has a flat transverse velocity profile. The Sub Sonic Open Circuit Wind Tunnel is simple and safe in operation. It is supplied as a complete self-contained facility mounted on castors for ease of movement. Main equipment comprises the tunnel with a three-component balance system (lift, drag and pitching moment) and an air speed indicator. One number of floor mount 3 component balance for lift force, drag force and pitching moment measurement is installed in the test section. A low angle diffuser at the outlet end contributes to flow stability in the test section. An axial flow fan is located at the outlet of the diffuser section.
Forces and moment data are digitally shown on LCD graphic display screen and are able to transfer to computer.  
Adjustment of pitch angle of models can be made with the tunnel in operation.  
Lift force: 0 to 100 N, sensitivity ±0.01 N
24 bit analogue to digital conversion of 3 strain gauge load cells for greater accuracy at low forces.  
The accuracy of the tunnel and its instrumentation make it suitable for undergraduate and simple research work.
Drag Force: 0 to 50 N, sensitivity ±0.01 N
Pitching Moment: 0 to 2.4 Nm, sensitivity ±0.001 Nm. 

Turbulent Jet

The apparatus is shown mounted on the working surface of the basic Air Flow Bench and connected to the blown experiment duct of the fan by a re-enforced plastic hose. The equipment consists of a plenum chamber with outlet tube and a calibrated stand to mount the pitot tube which can then be traversed along the axis of the air flow at various heights. The pitot tube is connected to the larger of the two sloping manometers which is leveled and zeroed before starting the experiments.
Although used with the basic Air Flow Bench the apparatus can be operated as a standalone unit if supplied with an air flow of approximately 500 litres/second at a pressure of 600 Pascals.

Introduction:
The student can then study air jet velocity in order to determine both velocity and momentum profiles of the air jet at various distances from the emission point.
Turbulent Jet Studies apparatus is designed to demonstrate the general behaviour of a jet of air emitted from a circular pipe into free surroundings.