Abstract—

The digital acoustic model of a nuclear reactor (NRDAM) is represented as a self-oscillatory system belonging to a special class of nonlinear dissipative systems that can generate sustained oscillations whose parameters do not depend on the initial conditions and are only governed by the properties of the system itself. It has been found that a pressurized water reactor with coolant flowing in a turbulent mode is an open system of high complexity with a large number of components with links between them being probabilistic rather than predetermined in nature. The coolant loop components featuring negative dissipation (negative friction) are revealed. It is shown that chaotic turbulent pulsations and vortices are self-organized in these components into ordered wave oscillations, the frequency of which is determined according to the Thomson (Kelvin) formula. An electronic generator of self-oscillations with a transformer feedback used in radio engineering circuits has similar properties. A nozzle is an acoustic analog of a transformer. A negative resistance contained in nonlinear dynamic systems like a nozzle or a natural circulation loop results in that chaotic turbulent disturbances become self-organized, and self-oscillations are generated in the form of acoustic standing waves (ASW). Based on theoretical and experimental data, the certainty of the ability of a reactor together with the pipelines connected to it to simultaneously generate several ASWs—a property that has not been known previously—is confirmed. By using the NRDAM in designing and operation of nuclear power plants (NPPs), it becomes possible to reveal the sources of ASWs arising in the coolant, their occurrence conditions, and frequency. The use of the NRDAM is also necessary for determining the effect that the coolant circuit equipment geometrical parameters and layout have on the interaction of neutronic, thermal-hydraulic, and vibroacoustic processes. By applying the NRDAM, it becomes possible to optimize the engineering and design solutions in developing new-generation NPPs by eliminating the conditions causing the occurrence of undesirable self-oscillations of coolant and vibroacoustic resonances resulting from the coincidence of the ASW frequencies with the vibration frequencies of nuclear fuel and equipment in normal and emergency operation modes and also under the conditions of shock impacts and seismic loads.

中文翻译：

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压水反应堆的数字声学模型

摘要-

核反应堆的数字声学模型 (NRDAM) 表示为属于一类特殊非线性耗散系统的自振荡系统，该系统可以产生持续振荡，其参数不依赖于初始条件，仅受系统本身。已经发现，冷却剂以湍流模式流动的压水反应堆是一个高度复杂的开放系统，具有大量组件，它们之间的联系是概率性的，而不是本质上预先确定的。显示具有负耗散（负摩擦）的冷却剂回路组件。结果表明，混沌湍流脉动和涡旋在这些分量中自组织成有序波振荡，其频率根据汤姆森（开尔文）公式确定。无线电工程电路中使用的带有变压器反馈的自激电子发生器具有类似的特性。喷嘴是变压器的声学模拟。非线性动力系统（如喷嘴或自然循环回路）中包含的负阻力导致混沌湍流扰动变得自组织，并以声驻波 (ASW) 的形式产生自振荡。根据理论和实验数据，反应堆及其连接的管道能够同时产生多个 ASW（以前未知的特性）的能力得到确认。通过在核电厂 (NPP) 的设计和运行中使用 NRDAM，揭示冷却剂中 ASWs 的来源、它们的发生条件和频率成为可能。NRDAM 的使用对于确定冷却剂回路设备几何参数和布局对中子、热工水力和振动声过程相互作用的影响也是必要的。通过应用 NRDAM，可以消除由于 ASW 频率与振动频率重合而导致发生不希望的冷却剂自振荡和振动声共振的条件，从而优化开发新一代核电厂的工程和设计解决方案核燃料和设备在正常和应急运行模式下以及在冲击和地震载荷条件下。它们的发生条件和频率。NRDAM 的使用对于确定冷却剂回路设备几何参数和布局对中子、热工水力和振动声过程相互作用的影响也是必要的。通过应用 NRDAM，可以消除由于 ASW 频率与振动频率重合而导致发生不希望的冷却剂自振荡和振动声共振的条件，从而优化开发新一代核电厂的工程和设计解决方案核燃料和设备在正常和应急运行模式下以及在冲击和地震载荷条件下。它们的发生条件和频率。NRDAM 的使用对于确定冷却剂回路设备几何参数和布局对中子、热工水力和振动声过程相互作用的影响也是必要的。通过应用 NRDAM，可以消除由于 ASW 频率与振动频率重合而导致发生不希望的冷却剂自振荡和振动声共振的条件，从而优化开发新一代核电厂的工程和设计解决方案核燃料和设备在正常和应急运行模式下以及在冲击和地震载荷条件下。NRDAM 的使用对于确定冷却剂回路设备几何参数和布局对中子、热工水力和振动声过程相互作用的影响也是必要的。通过应用 NRDAM，可以消除由于 ASW 频率与振动频率重合而导致发生不希望的冷却剂自振荡和振动声共振的条件，从而优化开发新一代核电厂的工程和设计解决方案核燃料和设备在正常和应急运行模式下以及在冲击和地震载荷条件下。NRDAM 的使用对于确定冷却剂回路设备几何参数和布局对中子、热工水力和振动声过程相互作用的影响也是必要的。通过应用 NRDAM，可以消除由于 ASW 频率与振动频率重合而导致发生不希望的冷却剂自振荡和振动声共振的条件，从而优化开发新一代核电厂的工程和设计解决方案核燃料和设备在正常和应急运行模式下以及在冲击和地震载荷条件下。