Research Of Vibration Damping Technology Of A Large-scale Wind Tunnel Equipment

To holding a position in the area of spaceflight, some rising Economic power economics begin to develop their urgent wind tunnels these years, and these facilities trend towards bigger caliber and simulating higher mach number. Large-caliber and high-pressure drive modes result in big impact force when these wind tunnels work, bigger than 500 tons sometimes. Such impact forces do harm to either the toft or the buildings nearby, and long-term running of these facilities would make the toft craze and be very dangerous. Further more,the big impact forces will conduct to the models through toft, and affect the test results. So the vibration-reduction framework must be designed to reduce the impact force of wind tunnel. To obtain an effective and feasible damper, modern simulation analysis method could be used in the design and optimization of damper system iteratively, and the results will sustain the design of damper.The mainly contributions of this research are listed as follows:① The effect of fluid damper’s parameter on the vibration-reduction system in the 2m shock tunnel is studied by using lumped parameter analysis methods. The effects of radius of the piston pinhole in the damper(R1) and radius of flow-limiting bolt(R2) on displacement of the test section and reaction force from ground are mainly studied. finite element method is used to model the vibration-reduction system, and structure characteristic of test section and install manner of fluid damper are both taken into account. The effect of vibration-reduction system is analyzed. Validation is done by comparing the two results, and a reasonable effect of vibration-reduction system is brought forward finally.② A large scaled impulse vitiated wind tunnel using rubber damper is simulated, and dynamics models for both with or without rubber damper are setup. The vibration-reduction effect of the damper is evaluated by several parameters, including horizontal displacement of centroid, rotating angle of concrete-toft test section, velocity of concrete-basis undersurface, and force on the damper. Finite element method is used to study and calculate the effect of the vibration-reduction system. Validation is done by comparing the two results. Then horizontal displacement of the wind tunnel’s concrete-toft centroid is obtained, effect of the rubber damper on the horizontal displacement is analyzed, and cushion effect of the damper on the force on test section is put forward.③ The large aperture shock tunnel is a large scaled facility to be built. Compared with the 2m shock tunnel, the impact force will be twice. The primary design of the vibration-reduction system is accomplished, and the system is modeled and studied by using lumped parameter analysis methods. According to the results, vibration-reduction effect is obtained, and improvement to the disadvantage is brought forward.All the wind tunnels studied are the most representative large scaled facilities with big impact force and strong destructive power when working. Lumped parameter and FEM are used to simulate the system, and the results are proved to be authentic and reasonable by tests. The studied and results provide better experience for simulation and sustain in theory for the construction of vibration-reduction system in larger scaled wind tunnels.