| Mechanical and fluid dampers have been placed at the bearing locations in turbomachinery to stabilize and attenuate vibration levels. Wire mesh, a material formed by compressing woven wires into the desired shape, is used in many industrial applications. This material possesses significant amounts of damping as was shown in previous studies. It requires no lubrication, cooling, or auxiliary systems. These favorable characteristics in addition to reliable operation under adverse conditions encouraged an in-depth investigation of wire mesh performance in vibration damping applications. Ring shaped wire mesh elements of different sizes, materials and densities were tested in this study to compound an understanding of how stiffness and damping behave with different design, installation and operational factors. The factors included radial thickness, radial interference fit, axial compression, response amplitude, excitation frequency, lubrication, cryogenic temperature and continuous vibration (endurance testing). A wire mesh element was installed in parallel with a structural bearing support and tested in a rotordynamic test rig at the Turbomachinery Laboratory of Texas A&M University. Vibration levels were drastically reduced when the wire mesh element was installed. These tests were conducted at several levels of axial compression applied to the wire mesh element. The tests proved the parallel arrangement valuable, with a primary advantage of allowing support stiffness modification without compromising damping. The results from studying the different factors were collectively used to investigate the sources of wire mesh damping and model its behavior. Several models were verified against collected data. Finally, engineering guidelines for designing wire mesh vibration dampers were developed based on the work of this research as well as previous efforts. The guidelines provide an optimized procedure for designing and testing wire mesh dampers in turbomachinery applications. Over all, wire mesh dampers in parallel with a structural support offer a solid alternative with many advantageous characteristics over conventional vibration dampers and traditional bearing supports. |
