NASA Ames Wind Tunnel Test 2007

This is a view of the test section of the wind tunnel, looking downstream. The mass simulator test article is the light colored metal cylinder angled up in the center. It is attached via an angle-adjusting link to the force balance, which is in turn attached to the verticle structure (movable up and down) in the center of the wind tunnel. The Cougar data-acquisition system and notebook computer are on the small table.

This is a view of the force balance (on the moving vertical section) and test article looking upstream.

This is another view of the force balance, angle-adjusting sting, and test article looking upstream in the test section of the wind tunnel.

The small devices labeled with numbers and having cables attached are accelerometers used to measure the motion of the structure when it is truck with an instrumented hammer.

A total of 8 accelerometer transducers, 4 in direction +Y (toward the camers) and 4 in direction +Z (up) were used to measure the response of the test article, force balance system, and support structure.

This is a view of the test article with transducers in positions 1 (closest to the camera) through 4 (fartheest from the camera). All excitation was done at position 1 and position 4, in the +Y and -Z directions. This was called transducer location set A.

Transducer location A1, channels 2 and 3.

Transducer location A2, channels 4 and 5.

Transducer location A3, channels 6 and 7.

Transducer location A4, channels 8 and 9.

Setting up for transducer location set B on the force balance and attachment structure.

Checking out transducer location set B in place.

Transducer location B5, channels 2 and 3.

Transducer location B6, channels 4 and 5.

Transducer location B7, channels 6 and 7.

Transducer location B8, channels 8 and 9.

Setting up for the third set of transducer Locations Set C on the support structure, still in the high positive angle of attack configuration.

An overview of the transducer Location Set C on the support structure.

Transducer location C9, channels 2 and 3.

Transducer location C10, channels 4 and 5.

Transducer location C11, channels 6 and 7.

Transducer location C12, channels 8 and 9.

Changing the angle of attack from a high positive value to a small negative value. This is at the zero degree angle of attack position. Note that the force balance system was raised up quite a ways for the negative angle of attack configuration.

This is the negative angle of attack configuration, with the force balance raised. For transducer location set E, the transducers were positioned along the test article as in location set A, but the coordinate locations of the transducers was different due to the changed angle of attack. The transducer locations D13-D16 corresponded to A1-A4.

Transducer location E17, channels 2 and 3. Locations E17-E20 correspond to locations B5-B8 except the coordinates have changed because the force balance is in a raised position.

Transducer location E18, channels 4 and 5.

Transducer location E19, channels 6 and 7.

Transducer location E20, channels 8 and 9.

Upper transducer locations for set F, channels 6-9.

Lower transducer locations for set F, channels 2-5.

Transducer location F21, channels 2 and 3.

Transducer location F22, channels 4 aqnd 5.

Transducer location F23, channels 6 and 7.

Transducer location F24, channels 8 and 9.

This is a view upstream of the negative angle of attack configuration showing the force balance and downstream extension.

Following data acquisition activities, the resulting transfer function and coherence data were transferred to an analysis notebook computer where resonance frequencies for the two configurations were compared to assess the completeness of and quality of the acquired data. The decision was made that an additonal small positive angle of attack configuration would not have to be analyzed and testing operations were completed.