There is a relevant hydraulic potential in Amazon rivers, from which it is generated most of the energy available for the largest part of Brazil. One of the most important hydropower plants in the Amazon is Tucuruí dam, which can produce 8370 MW through Francis turbines. This kind of turbine often presents hydrodynamic issues due to the vortex rope formation, which can induce vibrations and reduce assembly operating life. The present work concentrates in a computational study to determine the frequency pressure fluctuations in a hydraulic generation unit of the Tucuruí hydroelectric power plant. A numerical technique is applied for modeling the turbulent flow throughout the generation unit in a transient regime using finite volume method. For the analysis of velocity and pressure fields on the hydrogenerator, a 3D fully turbulent transient modeling for characterizing the pressure fluctuations at the runner outlet is performed. The structure of vortex rope formed is investigated in order to evaluate the hydrodynamic phenomena resulting from the turbine operating condition. Low-frequency pressure pulsations are caused by the movement of the vortex rope at the runner outlet. Additionally, vortex shedding dynamics is heavily influenced by the turbine operating conditions, demonstrating the importance of such investigation. For 63% distributor opening, the structure of the vortex rope reaches a big size in the suction duct, increasing the possibility of vibration. For 89% distributor opening, the turbine operates under overload condition, and the vortex rope becomes unstable. Comparisons with field data show the efficiency and validity of the numerical modeling, demonstrating good agreement.

亚马逊河具有一定的水力潜力，可以利用它来产生巴西大部分地区的大部分可用能源。亚马逊最重要的水力发电厂之一是图库里大坝，它可以通过弗朗西斯水轮机发电8370兆瓦。由于涡流绳的形成，这种涡轮机经常会出现流体动力学问题，这会引起振动并缩短组件的使用寿命。目前的工作集中在计算研究上，以确定图库里水力发电厂水力发电装置的频率压力波动。应用了一种数值技术，以有限体积法在瞬态状态下对整个发电单元内的湍流进行建模。为了分析水轮发电机的速度和压力场，进行了3D全湍流瞬态建模，以表征流道出口处的压力波动。研究形成的涡流绳的结构，以评估由涡轮机运行状况引起的流体动力学现象。低频压力脉动是由转轮出口处涡流绳的运动引起的。另外，涡流脱落动力学受到涡轮机运行条件的严重影响，证明了这种研究的重要性。对于63％的分配器开口，涡流绳的结构在吸气管中达到较大尺寸，从而增加了振动的可能性。对于89％的分配器开度，涡轮在过载条件下运行，涡流绳变得不稳定。