Page - 1449 - in Book of Full Papers - Symposium Hydro Engineering

2. PRESUMPTIONS AND SIMPLIFICATIONS OF THE MODEL These are parameters and facts whose application leads to a partial simplification of the examined phenomenon. In the task, it is not necessary to take into account every detail. Therefore, the task remains with the basic settings of the model, but the examined phenomenon will be sufficiently described. The model should be configured to match the reality or physical model as much as possible. The following assumptions were implemented to the modelling process:  Isothermal system - is a system where the temperature is constant, throughout the system.  Air entrainment - there are two fluids set in the entire object. It is air and water; however, their mutual mixing is not taken into account, due to pressure changes in the turbulent flow. Requires a very fine computation network.  Roughness - the way to divide this variable into a real object is too complicated. Because the surface is concrete, although partially degraded, there is expected a large flow rate. Therefore, the effect is minimal on the flow rate.  Boundary condition - are for all software products the same (margins = wall, inside = atmosphere, discharge = continuous). Only the inlets are different. It depends on the desired setting of individual software product.  Turbulence - option in all software products is used the same two-equation turbulent model k − ω [1] for calculation of all parameters. 3. CASE STUDY The comparison of individual programs took place on the existing water work. Slušovice dam is located near the village of Slušovice in the southeast of the Czech Republic and is managed by state owned enterprise Povodí Moravy. Its primary function is the drinking water supply and flood protection as well. The side channel spillway is located on the left bank of the reservoir. Spillway and chute are reinforced concrete structures. The shape of the overflow edge in the cross section is circular with a radius of 0.75 m. The length of the spillway edge is 26.8 m and the channel width is 6.0 m. The original (designed) flow capacity of the object is 89.5 m3/s for the maximum level in the reservoir. 1449