Mathematical modelling of flow and sediment transport – the Tisa dam case study

Velike brzine toka nizvodno od brane na rijeci Tisi kod Novog Bečeja (Srbija), uzrokovane velikom razlikom u vodostaju između uzvodnog i nizvodnog toka, dovode do erozije obale na desnoj strani neposredno nizvodno od pomoćnog preljeva, zbog čega je ugrožena i stabilnost brane. Imajući u obliku složenu interakciju parametara toka i pronosa nanosa na toj lokaciji, u radu se koristi pristup utemeljen na prostornom (3D) matematičkom modelu tečenja i pronosa nanosa koji je namijenjen za rješavanje takvih složenih procesa. Modelom je definirano optimalno rješenje koje udovoljava svim zahtjevima stabilnosti analiziranih građevina, pri čemu se uspoređuju rezultati dobiveni analizom postojećih uvjeta s rezultatom mjera koje se predlažu za rješavanje problema.High flow velocities downstream of the Tisa Dam at Novi Bečej (Serbia), produced by the large difference between water levels in the upstream and downstream reaches, cause bank erosion by the right bank immediately downstream of the emergency spillway, threatening stability of the dam itself. Due to complex interaction between the parameters of flow and sediment transport at the given location, an approach involving a spatial (3D) mathematical model of flow and sediment transport, aimed at solving such complex processes, is investigated in this paper. An optimum solution meeting all requirements for the stability of structures in question has been reached by the model, through comparison of the results generated by the existing conditions with the result provided by the measures proposed to fix the problems