Hydraulic calculations on spillway now remained largely stable flow properties. In this report the author presents hydraulic calculation of spillway by instability characterized methods and calculation of water energy dissipation after spillway by means of digging pools. | Lê Xuân Long Tạp chí KHOA HỌC & CÔNG NGHỆ 139(09): 77 - 81 CALCULATION OF HYDRAULIC CHARACTERISTICS OF CHUTE SPILLWAY AND ENERGY DISSIPATION Le Xuan Long* College of Technology - TNU SUMMARY Hydraulic calculations on spillway now remained largely stable flow properties. In this report the author presents hydraulic calculation of spillway by instability characterized methods and calculation of water energy dissipation after spillway by means of digging pools. Keywords: spillway, instability characterized methods, stable flow, unstable flow, energy dissipation INTRODUCTION* Spillway is now being widely used in hydropower plants and hydraulic contructions. Spillway flow is not steady flow under the influence of waves rolling over spillway phenomenon. Regulatory process makes flow reservoir water level continuously change, especially in the rainy season. The current calculation considers the uphill flow is steady flow of water, waterline usually pour water line b2, without regard to the change of flow and water levels over time. In this report the author presents how to calculate the flow unstable by characterized methods. p: Pressure : coefficient of kinetic energy repair; J: Slope hydraulic Equations (1) is explained by many different methods, mainly used to represent smooth flow in the channel system, river. In hydraulic contruction, flow on the spillway overflow flood discharge was flowing stream. To set the algorithm can be used in the hydraulic calculation of spillway, this report presents algorithms equations (1) characterized by the method used for the coordinates system fixed in the sectional and know before class time to experience the flow and depth. Modified Saint Venant equations we get: CHARACTERIZED METHODS Conveniently system characteristic equation [2]: Unstable flow slowly changing one way is represented by Saint Venant equations [4]: Q w S t 0 2 o v z p v g t s 2g J 0 (1) ds dt
