Results of the theoretical and experimental investigations of the turbulent mean swirl flows characteristics change along straight conical diffuser of incompressible fluid (air) are presented in this paper. The main swirl flow characteristics review is given. In addition: the specific swirl flow energy, the energy loss, the mean circulation, the swirl flow parameter, the ratio between the swirl and axial flow loss coefficients change along the diffuser are presented. Among other values: the Boussinesq number, outlet Coriolis coefficient and swirl flow loss coefficient dependences on inlet swirl flow parameter are also given. The swirl flow specific energy and outlet Coriolis coefficient calculation procedure are presented in this paper, as well as experimental test bed and measuring procedures. The swirl flow fields were induced by the axial fan impeller. Various swirl parameters were achieved by the impeller openings and rotational speeds.

hydraulic turbines to be continued by the experimental and analytical approaches on the axial fans pressure side. The complexity of 3-D, non-homogeneous, anisotropic turbulent velocity fields required complex experimental and theoretical approach, associated with the complex numerical procedures. Analytical approaches, complex statistical analyses and experimental methods and afterwards CFD employed in the research are presented in this paper. The 150 scientific papers, numerous diploma works, several master of science (magister) theses, six Ph. D. theses and two in progress, 40 researchers, national and international projects are the facts about the School. Scientific references are chronologically presented. Numerous abstracts from scientific conferences, presentations, projects with industry and lectures are not given here.Many researchers of the School of the turbulent swirling flow at the Faculty of Mechanical Engineering, University of Belgrade (FME UB) carried on and contributed to the research of the turbulent swirling flows . Vušković (1912Vušković ( -2005 published his first paper [1] in 1941, where he studied the problem of generation and stability of the vortex core in turbomachines, specifically behind the hydraulic turbine runners. Vušković continued his research and afterwards published paper [2], and Vušković and Velenšek [4].Obradović [3] discussed vortex hydrodynamic stability with constant circulation in the cylindrical pipes.Determination of the dead water diameter behind the axial fan without guide vanes was done by Protić [5]. Also, he was the first to introduce the idea of investigating the turbulent swirling flow behind the axial fan in the pipe. Further investigations are conducted at the Chair for hydraulic machinery and energy systems and at the Chair for fluid mechanics FME UB.Experimental investigations of the turbulent swirling flow in the long lined straight pipes behind the axial fan without guide vanes started at the FME UB in 1972, when experimental test rig was built and measurement equipment was designed by Benišek. First results from this test rig were published in [6,7,9,13]. Čantrak S. [19] was the first to commence investigations of turbulence at the FME UB and implemented turbulence statistics in the turbulent swirling flow.These investigations are ongoing getting deeper into the turbulent swirling flow phenomenology. The defended theses and published papers are part of this review and are listed in references. Chronologically are presented almost all scientific papers, a number of master of science (magister) theses and six Ph. D. theses that belong to the School. Two Ph. D. theses in this field are in progress. Numerous diploma works were defended at the Chair for hydraulic machinery and energy systems and at the Chair for fluid mechanics FME UB in this field. Forty researchers from Serbia, and from abroad as well, are members of this School. National and international projects, numerous abstracts from scientific conferences, presentations, projects for industry and le...

Results of experimental investigations of the turbulent swirl flow in three straight conical diffusers with various diffuser total angles are presented in this paper. All three diffusers have the inlet diameter 0.4 m and total divergence angles 8.6?, 10.5?, and 12.6?. The incompressible swirl flow field is generated by the axial fan impeller, and for each diffuser several regimes were achieved by changing rotation number. Original classical probes were used for measurements. The distributions of the average main swirl flow characteristics along the diffuser are shown. Distributions of the inlet Boussinesq number, outlet Coriolis coefficient, ratio of the swirl and completely axial flow loss coefficients at conical diffuser on the inlet swirl flow parameter are also presented.

Fluid flow in curved channels with various cross-sections, as a common problem in theoretical and applied fluid mechanics, is a very complex and quite undiscovered phenomenon. Defining the optimum shape of the fluid flow boundaries, which would ensure minimum undesirable phenomena, like "dead water" zones, unsteady fluid flow, etc., is one of the crucial hydraulic engineering?s task. Method of kinetic balance is described and used for this purpose, what is illustrated with few examples. .