Currently, gas turbine manufacturers frequently face the problem of strong acoustic combustion-driven oscillations inside combustion chambers. These combustion instabilities can cause extensive wear and sometimes even catastrophic damage of combustion hardware. This requires prevention of combustion instabilities, which, in turn, requires reliable and fast predictive tools. We have developed a two-step method to find a set of operating parameters under which gas turbines can be operated without going into self-excited pressure oscillations. As the first step, an unsteady Reynolds-averaged Navier–Stokes simulation with the flame speed closure model implemented in the OpenFOAM® environment is performed to obtain the flame transfer function of the combustion set-up. As the second step time-domain simulations employing low-order network model implemented in Simulink® are executed. In this work, we apply the proposed method to the Beschaufelter RingSpalt test rig developed at the Technische Universität München. The sensitivity of thermoacoustic stability to the length of a combustion chamber, flame position, gain and phase of flame transfer function and outlet reflection coefficient are studied.

中文翻译：

---

燃气轮机燃烧室中压力波动预测的两步法

当前，燃气轮机制造商经常面临燃烧室内强烈的由声​​燃烧驱动的振荡的问题。这些燃烧不稳定性会导致广泛的磨损，有时甚至会损坏燃烧硬件。这需要防止燃烧不稳定性，这又需要可靠且快速的预测工具。我们已经开发出一种分两步的方法来找到一组运行参数，在这些运行参数下燃气轮机可以运行而不会出现自激式压力振荡。第一步，执行不稳定的雷诺平均Navier-Stokes仿真，并在OpenFOAM®环境中实施火焰速度闭合模型，以获取燃烧装置的火焰传递函数。作为第二步骤，执行采用Simulink®中实现的低阶网络模型的时域仿真。在这项工作中，我们将建议的方法应用于由慕尼黑工业大学开发的Beschaufelter RingSpalt测试装置。研究了热声稳定性对燃烧室长度，火焰位置​​，火焰传递函数的增益和相位以及出口反射系数的敏感性。