Mathematical modelling of the rotor-driven revolving vane compressor with fixed vane (RV-I) with consideration of the vane thickness

Abstract

The rotor-driven revolving fixed vane (RV-I) compressor was introduced in 2008. It has been shown to exhibit superior mechanical performance as compared to conventional rotary compressors and the original revolving vane compressor design due to its unique cylinder-rotor arrangement. In such a machine, both the rotor and the cylinder rotate together with the help of the vane, resulting in significantly reduced frictional losses. Mathematical models had been developed and validated to simulate the characteristics of RV-I compressors. These models typically assumed negligible vane thickness to simplify the analysis. In this paper, a modified mathematical model for RV-I compressors that includes the vane thickness is introduced and discussed. The model consists of three main parts, i.e. geometry/kinematics, dynamics and thermodynamics. The dynamics of the components are assumed to be geometrically constrained like in the previous models. Tests were carried out by comparing the results with the available models. It was found that the overall performance predictions from both models are not significantly different in the range of parameters tested. However, the model opens the way for more accurate modelling of the machine. One of the phenomena that was previously unobservable with conventional models is the ‘vane side flip’. This is when the contact point between the vane and the slot moves from one side of the vane to the other. Experimental data suggest that this maybe important for RV-I machines. However, the process is dynamically complex and is impossible to be simulated with a geometrically constrained model. A more accurate modelling of the machine requires a dynamically-constrained model that allows for a complex interaction of the forces, torques and impacts.