# Experimental Verification of a Compressor Drive Simulation Model to Minimize Dangerous Vibrations
## 1 Introduction  
Nowadays, ever growing emphasis is being placed on low levels of vibration and noise generated during the operation of machinery and equipment and transmitted to the surrounding area. They represent a detrimental factor in terms of environmental and general operational safety [1]. Numerical simulation tools such as Fluent software and k-\(\epsilon\) turbulence models are currently used to assess and control dangerous factors (including vibration) in the workplace [2].  
Vibrations have a negative effect on the operation of mechanical systems and on the safety of operation--their reliability and also their service life are reduced [3; 4; 5]. It is generally known that various types of sources are involved in the generation of vibrations in the structural parts of the machine, mainly unbalance, misalignment, mechanical clearance of the bearings, resonance of the structure, bent shaft, excessive wear of bearings, damage to the gearing [6; 7], lubrication [8; 9; 10], etc. These negative phenomena and their causes can be identified during the operation of the equipment by measuring the methods of technical diagnostics and monitoring [11; 12; 13]. As a result of inertial forces and variable load torque of individual machines and equipment, torsional oscillations occur [14; 15; 16; 17]. Torsional vibration can be dangerous, depending on the level for a particular mechanical system and the place of its occurrence. In torsionally oscillating mechanical systems (mainly mechanical systems with internal combustion engines [18; 19], piston compressors, piston pumps, and fans), which include flexible members, it is possible to reduce the dangerous torsional oscillation to an acceptable level by suitable adaptation of the dynamic properties (i.e., stiffness [20; 21; 22; 23; 24], damping coefficient [25], and mass moment of inertia [26]) of these members to the dynamics of the system [27; 28]. However, this may not only apply to elastic members but also to other members in the mechanical system. Recent developments include so-called active vibration isolation, where an additional torque is generated in real time directly at the driving electric motor or a special active damper [29; 30; 31; 32]. Dynamic properties largely affect the operation of the mechanical system, its lifetime, and reliability; therefore, to perform the above-mentioned procedure, the torsionally oscillating mechanical system needs to be appropriately tuned in advance [33]. The tuning of any mechanical system is most often verified on the basis of the results of the so-called Campbell diagram. It is used to determine whether resonance will occur [34]. The research of vibration problems in mechanical systems is not a new phenomenon in the field of engineering sciences. Vibrations represent phenomena occurring in every mechanical system since its manufacture. They are negative phenomena that interfere with the smooth operation of mechanical systems [35] and act as a threatening and risk factor. Therefore, it is both necessary and required to look for ways of their minimization [36; 37].  
Based on this fact, the main objective of this paper is to control the dangerous vibrations of the drive of a mechanical system by applying a pneumatic flexible coupling based on dynamic simulation models verified by experimental measurements. The main objective of the paper can be achieved by fulfilling the partial objectives, namely: selection of the comparison model, preparation of the mechanical system in the laboratory for experiments, obtaining input data for the model, calculation of natural frequencies and mode shapes, dynamic analysis, creation of the simulation model, realization of the experiments, verification of the model, and design of recommendations for control of dangerous vibrations.