IMPROVING CENTRIFUGAL PUMP BY ADDING VORTEX ROTOR

The improvements of the characteristics of centrifugal pump were investigated in this work experimentally and with computational fluid dynamics (CFD) analysis of the influence of adding vortex rotor to centrifugal one. The idea behind that improvement is in creating the so-called coherent structures of eddies and turbulence in the peripheral area of the vortex rotor mounted at the back side of centrifugal rotor. Research on the energy transformations in the centrifugal vortex pump in this work was carried out using control volume method for simulations of the flow in the centrifugal and the centrifugal vortex pump, and also by taking measurements of relevant parameters that describe the performance of pumps at their physical models. The measurement results were used as experimental validation and verification of numerical simulations; in contrast, flow visualization derived from the numerical simulation was used to interpret measurements. In deriving that experimental procedure, special care was taken with the flow measurements. The reason for this is in the fact that the flow measurements had the biggest influence on the overall measurement uncertainty. However, flow measurements were the most demanding with regard to experiment design and in taking the measurement readings. This experimental - CFD research made it possible to undertake an assessment of vortex rotor contribution on the head of centrifugal vortex pump. The influence of the vortex rotor on the efficiency of the centrifugal vortex pump was studied in contrast to the efficiency of a centrifugal pump with the same geometry. An analysis of the structure of flow was conducted in order to better understand the energy transformations that are the result of interaction between vortex rotor and the flow from the channels of centrifugal part of centrifugal vortex rotor.Original Abstract: Poboljsanja karakteristika centrifugalne pumpe istrazivana su u ovom radu primjenom eksperimenta i racunalne dinamike fluida (CFD). Istrazivan je utjecaj dodavanja vrtloznog na centrifugalni rotor. Pokretacka zamisao ovog nacina poboljsanja je u stvaranju tzv. tokova koherentnih struktura i turbulencije na vanjskom promjeru vrtloznog rotora koji je pricvrscen na straznjoj strani centrifugalnog rotora. Proucavanje energetskih transformacija u ovom radu provedeno je primjenom numericke metode kontrolnih volumena za simuliranje strujanja u centrifugalnom i centrifugalno vrtloznom stupnju te mjerenjem relevantnih paramet