The aim of the research is to improve the shape of the end site of hydrodynamic flow regulator in downstream for enlarging the range of pressure regulation. The improved design of hydrodynamic flow regulator was proposed. The design provides for applying as an end site of the rectangular diffuser with expansion ratio 4, angles of horizontal and vertical expansion 30° and 5° respectively in the presence of guide vanes. The study of the new construction was carried out by using experimental, numerical, and theoretical research methods. Simulation of free stream surface was done using two-phase interaction in Volume of Fluid method with gravitation term. Two-phase media was considered as single-phase fluid which properties varying according to volume portion of each phase presented. The model of turbulence used for calculations was based on the solution of averaged Reynolds equations. Turbulence was simulated by the standard set of constants. To verify obtained results by numerical simulation of fluid flow physical experiment was carried out in mirror hydraulic tray. The correctness of numerical simulation was proved by laboratory experiment, as well as the choice of basic size of calculating net. The result analysis made by three experimental procedures has shown that obtained values have good agreement to each other with an error less than 5 %. Limit value of relative coefficient of transient flow discharge, satisfied to alignment of water level in a fusion chamber and downstream, is equal to 0.77 which is satisfied the ratio 0.11 of driven and transient discharge that is the decreasing of capacity by 23 %. The range of pressure regulation was increased by 10.5 % comparing to construction of flow discharge proposed by S. I. Khusni.
Keywords: drawoff culvert, hydraulic facilities, hydrodynamic flow regulator, diffuser, guide vanes, expansion ratio.
