Ovcharenko M. The influence of the design and operating parameters on the energy characteristics of the multifunctional hydrodynamic homogenizing unit

The thesis for the candidate degree in technical sciences, speciality 05.05.17 - Hydraulic Machines and Hydropneumatic Units - Sumy State University, Sumy, 2013. The thesis work presents the results of the numerical, theoretical and physical simulation of the multifunction hydrodynamic homogenizing unit work process. Numerical simulation has allowed to confirm the analytical assumptions about the flow pattern in the hydraulic part of the unit, specifically, the vortex structures forming within the rotor and stator channels and the presence of high-gradient flow in the running clearance. The fields of pressure distribution and the contours of dissipation of the kinetic energy, the analysis of which has indicated that the main energy losses were collected within the interstage clearance, within the stator channels and at the outer radius of the rotor disk, are shown in this thesis work. Mathematical simulation methods were used during theoretical research. These methods are based on the classical equations of fluid mechanics as well as the known dependencies of the hydrodynamic characteristics of the turbulent unsteady flows in thin sealing clearances. Such simulation has allowed to identify the factors influencing greatly to the level of power consumption, but also it has pointed to the unsustainable energy losses on the backside of the rotor disk, which can be eliminated by means of the double suction impellers. Physical simulation has allowed to estimate the degree of impact of the design and operating parameters on the power consumption. So, the power depends on the rotational speed of the rotor to the power of 2.86, and on the diameter - to the power of 3. It is shown that increasing of the number of channels from 2 to 24 increases the flow rate up to 18 times with an increase in the power consumption just up to 2 times. The increase in the width of the channel leads to a steady increase in performance and power consumption. There was founded, that the width of the multifunction hydrodynamic homogenizing unit stage can not be considered as an analogue of the width of the impeller, as the increase in the width of the stage increases the hydraulic resistance to flow of fluid, running along the clearance. This thesis work describes a method of designing the unit, which is based on the developed mathematical model. The adequacy of the methodology and mathematical model is confirmed by designing and manufacturing of six industrial models. Practical recommendations for unit design for different processes were obtained on the base of under-control operation of the industrial models.