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.

An experimental setup for three-degree-of-freedom large-amplitude free vibration in a wind tunnel test. The setup includes a rigid test model, rigid circular rods, rigid lifting arms, arc blocks with grooves, lightweight high-strength thin strings, linear tensile springs, fixed pulleys, and bearings. Large-amplitude three-degree-of-freedom free vibrations of test models can be adapted by the vertical deformation of the springs without any tilt. The possible nonlinear mechanical stiffness due to vertical spring tilt and lateral spring deflection are excluded. It is convenient to install the test model and adjust the initial angle of attack in the new experimental setup. The linear stiffness property and hence constant vibration frequency can be ensured for very large-amplitude vibrations due to the eliminations of spring deflection and tilt.

The device described herein and the associated method relate, in particular, to a holding device for a wind tunnel test stand 1, in particular for a wind tunnel balance. The device may comprise a holding base 5a, 6a, which may be arranged outside of a conveyor belt 3 of the wind tunnel test stand 1, and a support element 7 having at least two ends 7a, 7b. Via a connection element 13, one end of the support element 7 may be connected to a wheel 22 of a test object 4. Furthermore, a support device 8 may be provided, which may be connected to the support element 7 in such a way that a change in a rotational orientation of the support element 7 can cause a lifting or lowering movement of the support device 8.

The invention provides a large-amplitude vertical-torsional coupled free vibration device, which belongs to the technical field of vertical-torsional coupled free vibration device for wind tunnel test. The gear blocks are consolidated at both ends of the beam. The screws, beam, and the gear blocks are fixed on the model, and they can fulfil the vertical-torsional coupled free vibration. The toothed plate is attached to the sliding block that iteratively moving along the vertical guide rail which is fixed to the ground. The vertical springs attached to the sliding blocks provide both vertical and torsional linear stiffness for the suspension vibration system. The springs only have vertical linear tensile deformations without any lateral tilt, which ensures the linear vertical and torsional stiffness of the model, and the lateral freedom is effectively restrained. This device can achieve the large-amplitude vertical-torsional coupled free vibration of the model, and the deficiency of the traditional device where springs are apparently tilted and the inefficacy of linear stiffness can be avoided. The lateral vibration is restrained, and it is applicable to large-amplitude vertical-torsional coupled free vibrations.

A multi-dimensional vibration control method based on piezoelectric ceramic actuator applied to wind tunnel test of aircraft model. The pitch and yaw acceleration sensors arranged on the center of mass of the aircraft model are used to measure the two components of the main vibration acceleration of the aircraft model, and the main vibration vector of the aircraft model is obtained and the real-time vibration plane of the strut is determined. Inertia is introduced to solve the dynamic bending moment on the active section of the multi-dimensional vibration damper, and then the stress distribution on the active section is obtained. The multi-dimensional active vibration control system is adopted to improve the stability and reliability of the active vibration control system of wind tunnel model, extend the service life of piezoelectric ceramic actuator, and ensure the quality of wind tunnel test data and the safety of wind tunnel test.

A large-amplitude vertical-torsional coupled free vibration testing device for wind tunnel test. The large-amplitude vertical-torsional coupled free vibration device for wind tunnel test includes rigid deck model, lightweight rigid rods, lightweight rigid circular aluminium hubs, the first thin strings, linear tensile vertical springs, and the second lightweight strings. Large-amplitude vertical-torsional coupled free vibrations of rigid deck models can be realized by using this device, in which the springs vertically deform without any tilt. In the traditional free vibration device, the spring may obviously tilt, and the linear torsional stiffness cannot be ensured. The device can be conveniently installed and the initial angle of attack can be easily adjusted. The extreme low and stable mechanical damping ratio required for large-amplitude vibrations can be readily guaranteed, owing to the invocation of the negligible rolling friction between the thin strings and the hub.

An experimental setup for bridge deck large-amplitude vertical-torsional coupled free vibration in wind tunnel test, which belongs to the technical field of wind tunnel test apparatus. The experimental setup includes the rigid model, the rigid circular rods, the lightweight rigid circular sprockets, the chains, the linear tensile vertical springs, the bearings, the sliders, and the guides. For the new setup, large-amplitude vertical-torsional coupled free vibration of a rigid deck model that failed in conventional testing device can be adapted by the vertical deformation of the springs without any lateral tilt. As a result, the possible nonlinear mechanical stiffness due to the springs tilt in conventional testing device is excluded. In addition, owing to the low rolling friction and damping between the sprockets and the chains, the mechanical damping ratio of the system are quite low and stable for very large-amplitude vibrations.

A test fixture for measuring the skin friction of anisotropic surface finish on a material is described. The test fixture can be utilized in a wind tunnel. The test fixture can include a plate having a cavity configured to receive a circular specimen disk. A motor can be coupled to the plate to rotate the circular specimen disk. During a test, a fluid can flow over the plate in a particular direction and the motor can rotate the circular specimen disk to determine the effect of the flow angle on the average skin friction coefficient of a surface finish of a material. The circular specimen disk can easily be attached and detached from the test fixture to allow circular specimen disks with different surface finishes to be tested.

This disclosure provides a balance for air resistance testing, compromising 2N dual-hole beam sensors and an upper plate; wherein, the 2N dual-hole beam sensors are arranged beneath the upper plate and fixed to the upper plate; each said dual-hole beam sensor comprises a beam, an upper hole and a lower hole, the upper hole and the lower hole are arranged along the longitudinal direction of the beam, the upper hole is arranged at the upper part of the beam, and the lower hole is arranged at the lower part of the beam.

Wind tunnel test stand for motor vehicles convertible into multiple configurations including a one-belt, three-belt and/or five-belt configuration. The wind tunnel test stand includes force sensors for sensing forces between a weighing platform and a test stand frame, a belt unit with a conveyor belt, and a carriage accommodating at least one belt unit, where the carriage is supported relatively movably with respect to the test stand frame in X- and Y-directions.