Abstract: A wind tunnel sting comprising a support member and a wind tunnel sting damper. The support member having a first support-member end configured for coupling with a wind tunnel, and a second support-member end configured for coupling with a balance. The wind tunnel sting damper having a reactive member, and a viscoelastic member disposed between the reactive member and the support member wherein, the reactive member is sized relative to the support member so as to radially compress the viscoelastic member against the support member.

Abstract: A wind tunnel sting comprising a support member and a wind tunnel sting damper. The support member having a first support-member end configured for coupling with a wind tunnel, and a second support-member end configured for coupling with a balance. The wind tunnel sting damper having a reactive member, and a viscoelastic member disposed between the reactive member and the support member wherein, the reactive member is sized relative to the support member so as to radially compress the viscoelastic member against the support member.

Abstract: A test stand for characterization of a tunable mass damper may include (a) a support base including a stop member, (b) a test plate coupled to the support base, with the test plate configured to move relative to the support base and to fixedly carry a tunable mass damper, (c) a spring coupled to the support base and the test plate, (d) a lever configured to be releasably coupled to the test plate and to move the test plate relative to the support base against the urging of the spring, and (e) a latch mechanism configured to release the test plate from the lever when the test plate is at a predetermined position relative to the support base. The motion of the test plate, after the test plate has been released by the latch mechanism, may be halted by the stop member of the support base.

Abstract: A tunable mass-damping apparatus may include a housing having an interior surface, an interior volume containing a fluid, and an axis. The housing may be configured to be coupled to a wind tunnel model. The apparatus may further include a mass configured to move back and forth in the interior volume along the axis. The mass may be configured to make an airtight seal with the interior surface of the housing, thereby dividing the interior volume into an upper chamber and a lower chamber. The apparatus may include a passage fluidly connecting the upper chamber and the lower chamber and a spring configured to exert a position-dependent force upon the mass. The spring may be characterized by a variable spring constant chosen based on a variable natural frequency of a support structure of the wind tunnel model. The variable spring constant may be established with a nickel-titanium alloy spring heated to at least one calibrated temperature that corresponds to a predetermined spring constant.

Abstract: A test stand for characterization of a tunable mass damper may include (a) a support base including a stop member, (b) a test plate coupled to the support base, with the test plate configured to move relative to the support base and to fixedly carry a tunable mass damper, (c) a spring coupled to the support base and the test plate, (d) a lever configured to be releasably coupled to the test plate and to move the test plate relative to the support base against the urging of the spring, and (e) a latch mechanism configured to release the test plate from the lever when the test plate is at a predetermined position relative to the support base. The motion of the test plate, after the test plate has been released by the latch mechanism, may be halted by the stop member of the support base.

Abstract: A tunable mass-damping apparatus may include a housing having an interior surface, an interior volume containing a fluid, and an axis. The housing may be configured to be coupled to a wind tunnel model. The apparatus may further include a mass configured to move back and forth in the interior volume along the axis. The mass may be configured to make an airtight seal with the interior surface of the housing, thereby dividing the interior volume into an upper chamber and a lower chamber. The apparatus may include a passage fluidly connecting the upper chamber and the lower chamber and a spring configured to exert a position-dependent force upon the mass. The spring may be characterized by a variable spring constant chosen based on a variable natural frequency of a support structure of the wind tunnel model. The variable spring constant may be established with a nickel-titanium alloy spring heated to at least one calibrated temperature that corresponds to a predetermined spring constant.