Wind Tunnel Testing ($25.00/hour) BACK
AeroRocket can assist you in determining Drag (CD), Lift (CL), pitch-moment (CM), lift slope (CLa) and pitch-moment slope (CMa) for almost any aerodynamic shape utilizing its own subsonic wind tunnel and two-component force measurement system. The wind tunnel at AeroRocket's disposal was developed in-house to provide a wide range of drag, lift, velocity and pressure profile measurements. The test section is 7 inches wide x 10 inches high and is 16 inches long. Maximum test section velocity is 80 ft/sec with a test item installed. The AeroRocket wind tunnel is ideal for measuring subsonic drag and flow visualization of unusual rocket designs like the SS1 and shapes not treated by AeroDRAG or any other rocket analysis computer program until the development of AeroCFD and VisualCFD. The AeroRocket subsonic wind tunnel is ideal for measuring drag and lift using the in-house built two-component force measurement instrumentation system.

Basic Cost Information
Subsonic Wind Tunnel: Cost for using the AeroRocket subsonic wind tunnel is $25 per hour and reflects a 50% reduction from the normal AeroRocket consulting fee of $50 per hour. The AeroRocket subsonic wind tunnel testing fee includes set-up time, aerodynamicist labor required to operate the wind tunnel and data presentation. Set-up typically takes one hour and actual measurement time will vary depending upon the number of measurement points requested. For drag and lift wind tunnel testing at a single angle of attack, total wind tunnel time is approximately 3 hours for a total of $75 when utilizing a customer supplied wind tunnel model. For more complex wind tunnel measurements, a customer supplied project description and test matrix is required to accurately determine total cost for wind tunnel usage. Please contact AeroRocket to receive a cost estimate for your specific wind tunnel requirement.

Supersonic Wind Tunnel: Cost for using the AeroRocket supersonic shock-tube wind tunnel is $100 per hour reflecting the labor intensive nature of shock-tube wind tunnel testing. Presently, measurements are limited to determination of drag coefficient (CD) at Mach 1 to Mach 5. Measuring CL is a future capability for the AeroRocket shock tube wind tunnel. Please contact AeroRocket to receive a cost estimate for your specific supersonic wind tunnel requirement.

Model Requirements
Customer's model must be 12 inches long or less.
Customer's model over-all width must be 3.25 inches or less.
Customer should supply a 1/4" diameter mounting hole at the center of gravity of the model to insert a sting for testing purposes. However, if the model is not to delicate AeroRocket will drill the sting mounting hole. AeroRocket will also supply the sting.
For supersonic wind tunnel models please email for more information.

Wind Tunnel Model Fabrication
Subsonic Wind Tunnel: For a cost of only $50 per hour AeroRocket will fabricate your wind tunnel model. Just mail or email your model's dimensions using the requirements listed above as guidelines for model fabrication. A Typical wind tunnel model can be fabricated in about 2 to 10 hours and will cost approximately $100 to $500 depending on the level of detail required. The HTV-3X, HL-20, X-30 NASP, X-43 and Sprint ABM wind tunnel models pictured below were fabricated by AeroRocket. Wind tunnel model fabrication costs in this group range from $500 for the HTV-3X to $100 for the Sprint ABM.

Supersonic Wind Tunnel: Supersonic shock tube wind tunnel models cost $100 per hour to fabricate reflecting the difficulty in making miniature supersonic wind tunnel models. A miniature shock tube wind tunnel model like the HTV-3X pictured above costs $500 to fabricate.

Wind Tunnel Testing Ordering Instructions BACK
Cost for testing a customer supplied subsonic wind tunnel model is $25 per hour. A typical series of subsonic wind tunnel tests as described in the TECHNICAL DETAILS section cost approximately $250. Please contact AeroRocket for a FREE quote for testing your specific model in the AeroRocket Wind Tunnel. When contacting AeroRocket for the first time concerning wind tunnel testing please provide a "test matrix" that includes model configuration (geometry), AOA, velocity, and whether the model is to be tested using the vertical-sting or rear-sting mounting technique. Please review the TECHNICAL DETAILS section prior to deciding which type of mounting is appropriate. In addition, center of pressure location testing and flow visualization testing are available and illustrated below. Please contact AeroRocket by e-mail for prompt attention to all wind tunnel testing requests. Telephone requests for wind tunnel testing cannot and will not be accepted.

COST SUMMARY
Subsonic Wind Tunnel Testing @ $25 per hour
Subsonic Wind Tunnel Model Fabrication @ $50 per hour
Supersonic Wind Tunnel Testing @ $100 per hour
Supersonic Wind Tunnel Model Fabrication @ $100 per hour
(Please email for a FREE quote)

Wind Tunnel Test Features BACK
Wind tunnel measurements at a maximum wind speed of 80 ft/sec (54.5 mph).
Drag (CD) and lift (CL) at 0, 5, 7.5, 10, 12.5, 15 and 17.5 degrees AOA using vertical-sting or rear-sting mounted models for angles of attack ranging from 0.0 degrees to 40 degrees AOA.
Center of Pressure location (XCp) measurement.
Flow visualization using probe-mounted yarn filaments or smoke that define areas of reverse flow and vortical motion corresponding to lift.
Experiments photographically documented.
Turbulent flow measurement using trip-wire if required.
Report summarizing the results.

Drag (CD) and Lift (CL) Coefficients BACK
Figure-1 illustrates the force balance system used to determine rocket drag (CD) and lift (CL) of a wind tunnel model mounted on a vertical-sting. Displacement in the axial (drag) and vertical (lift) directions are measured using the two load cells labeled DRAG and LIFT respectively and then converted to drag and lift forces in Newtons using the Vernier CBL-2 computerized data acquisition system. The force balance system pictured in Figure-1 is designed to separate the aerodynamic forces and the associated displacements in the axial and vertical directions when the weight on the force-balance plate causes the model to be freely suspended. Models tested in the AeroRocket wind tunnel may be mounted on a vertical-sting as in Figure-2 or mounted on a rear-sting as in Figure-3. Either mounting configuration may be selected depending on the objectives of the wind tunnel test.

Figure-1, Basic System For Measuring Drag (CD) and Lift (CL) Figure-2, Vertical-Sting Mounted Model, 0.0 to 15 Degrees AOA Figure-3, Rear-Sting Mounted Model, 0.0 to 15 Degrees AOA

Center of Pressure (XCp) Location Measurement BACK
Center of pressure location measurements are performed using a special XCp-Caliper that secures the model in the wind tunnel test section using two opposing low friction points. Figure-4 illustrates a ring-fin model rocket being tested in the AeroRocket wind tunnel for the determination of center of pressure location. The ring-fin model in this configuration is stable because the support point is ahead of the actual center of pressure. The actual center of pressure location (XCp) is determined by moving the sting support location rearward until the model becomes unstable and "noses over" to one side or the other when the wind tunnel is operating. Figure-5 further illustrates how the ring-fin rocket model is secured in place during center of pressure location testing. Please notice the pitot tube used to measure the difference between static pressure and dynamic pressure for determining flow velocity in the wind tunnel. An analog velocity meter is used to convert the resulting pressure differential to test section flow velocity in feet per minute (fpm).

Figure-4, Center of Pressure (XCp) Location Measurement Figure-5, XCp Measurement Instrumentation

Filament Flow Field Visualization BACK
A single-strand filament of low mass yarn on a long slender probe illustrates the flow on and around an object. Regions of reverse flow behind blunt bodies become visible. Please refer to Figure-6, Figure-7 and Figure-8 to see how the base flow of the Sprint ABM is investigated using a yarn tuft on a probe. In addition, regions where the flow rotates indicate stream wise vorticity and therefore lift and circulation. Please refer to Figure-9, Figure-10 and Figure-11 to see how the fin-tip vortical flow pattern of the X-43 at an angle of attack of 15 degrees is investigated using a yarn tuft on a probe. Please note the three photographs of the X-43 are of the yarn filament as it rotates in the clockwise direction as viewed from the front of the wind tunnel model.

FILAMENT FLOW VISUALIZATION Figure-6, Sprint ABM Base Flow on Rear-Sting Mount Figure-7, Sprint ABM Base Flow Circulation on Rear-Sting Mount Figure-8, Sprint ABM Base Flow Circulation on Vertical-Sting Mount Figure-9, X-43 Fin-Tip Vortical Circulation (1) Figure-10, X-43 Fin-Tip Vortical Circulation (2) Figure-11, X-43 Fin-Tip Vortical Circulation (3)