Along with the developments of high-speed and highperformance turbomachines, there has been increasing occurrence of rotational speeds higher than the first critical speed. Under these circumstances, turbomachines may suffer from severe vibration and rotor whirl caused by fluid-dynamic forces. As possible causes of whirling instabilities, fluid forces on journal bearings and seals are well know...

Dynamic model of bearing-rotor system is developed considering the collision effects between cage and its guiding land. The modal characteristic vibration response are studied with fourth-order Runge-Kutta method. It demonstrated that whirling motion arising as a result land would induce abnormal frequency components in system’s including multiple well modulation speed natural frequency. Additi...

A pressure-based computational fluid dynamics (CFD) code is employed to calculate the flow field and rotordynamic forces in a whirling, grooved liquid annular seal. To validate the capabilities of the CFD code for this class of problems, comparisons of basic fluid dynamic parameters are made to three-dimensional laser Doppler anemometer (LDA) measurements for a spinning, centered grooved seal. ...

Introduction and spread of the parasite Myxobolus cerebralis, the causative agent of whirling disease, has contributed to the collapse of wild trout populations throughout the intermountain west. Of concern is the risk the disease may have on conservation and recovery of native cutthroat trout. We employed a Bayesian belief network to assess probability of whirling disease in Colorado River and...