Real-world products and physics-based simulations are becoming interconnected. In particular, real-time capable dynamic simulation has made it possible for simulation models to run in parallel and simultaneously with operating machinery. This capability combined with state observer techniques such as Kalman filtering have enabled the synchronization between simulation and the real world. State estimator techniques can be applied to estimate unmeasured quantities, also referred as virtual sensing, or to enhance the quality of measured signals. Although synchronized models could be used in a number of ways, value creation and business model development are currently defining the most practical and beneficial use cases from a business perspective. The research reported here reveals the communication and collaboration methods that lead to economically relevant technology solutions. Two case examples are given that demonstrate the proposed methodology. The work benefited from the broad perspective of researchers from different backgrounds and the joint effort to drive the technology development towards business relevant cases.

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In an active magnetic bearings (AMBs) supported rotor system, the touchdown bearings have been proposed to support the rotor during an electromagnetic field shortage. The heat generation due to the high impact and collision of the rotor and touchdown bearing, in addition to the internal friction in the bearing, raises the temperature of the touchdown bearing. In this work, a numerical model is applied to simulate the rotor dropdown where the FEmodel of the rotor is integrated with the dynamic and thermal model of the touchdown bearing. The rotor that is used as a case study is supported by a deep groove ball bearing and a pair of angular contact ball bearings installed in an X-configuration. The present study focuses on evaluating different orders of surface waviness in a pair of angular contact ball bearings. The equivalent electrical circuit model is implemented for computing the thermal behavior of the touchdown bearing. Results indicated that the dynamic friction coefficient between the rotor and inner race has a considerable impact on bounce height and the whirling motion of the rotor. Furthermore, for a certain amplitude of surface waviness, the effect of various orders of waviness is investigated and it has been found that surface waviness of the bearing alters the contact force and friction loss in the touchdown bearing. In addition, the effect of a higher amplitude of surface waviness on thermal expansion of the touchdown bearing is studied.

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In the active magnetic bearings (AMBs) supported rotating machinery, touchdown bearings are considered as safety devices to support the rotor in the deficiency of electromagnetic field. Generally, the industrial AMB machines do not have force sensors for touchdown bearings and the system is only equipped with the position sensors to monitor the rotor displacement that disables the opportunity to measure the forces during dropdown events that might be destructive for the safe operation of the rotor system. This study explores the relative severity of dropdowns that are evaluated from a computational rotor model using the rotor displacement data recorded from the position sensors installed in the machine as an input. The model for double-row angular contact ball bearing type touchdown bearings is integrated with the rotor model. The simulation model is verified by comparing the simulated rotor orbits against measured orbits at four different dropdowns. The Fast Fourier transform (FFT) is used to observe the studied dropdown events in frequency domain revealing from the rotor response the following details: harmonics of the operation speed, rub-impact frequencies, pendulum motion of the rotor and the first two bending frequencies of the rotor settled on the touchdown bearings. The critical speed map also verifies the bending frequencies and identified support properties. The model-based approach can be used to evaluate and compare a single dropdown event with respect to previous events providing an insight for decision making whether touchdown bearing should be replaced.