Numerische Untersuchung der Lärmentstehung und der Lärmabstrahlung turbulenter Flammen

该研究项目的目的是加强对预混合湍流燃烧产生的噪声的物理认识。这种理解对于设计固定式燃气轮机和飞机发动机中的工业燃烧器是强制性的，这些燃烧器是环保的。问题是，在燃烧室的声学诱导不稳定强烈影响最佳操作条件。与项目第一阶段的合作伙伴(TP1 (Paschereit), TP2 （Janicka), TP4 (Bockhorn)）合作，将对通用燃烧器配置进行试点，以便燃烧器可以在精益预混状态下运行。研究了动量、温度、未燃烧气体的混合物以及喷嘴边界层湍流强度等参数对湍流火焰声发射的影响，并在声场的基础上对其进行了量化。TP1 （Paschereit）进行的实验将通过TP2 （Janicka）和TP4 （Bockhorn）的大涡模拟进行研究，以计算当前子项目TP3 （Schröder）的声场。此外，与TP2 （Janicka）合作，将研究火焰锋面正确声学模拟所需的数值解。此外，TP4 （Bockhorn）对直接数值模拟的详细评估将显著增强对声学扰动方程中声源公式的相关声源机制的了解。

The objective of the research project is to enhance the physical understanding of noise emission by pre-mixed turbulent combustion. This understanding is mandatory to engineer industrial burners in stationary gas turbines and aircraft engines that are environmentally friendly. The problem is that acoustically induced in-stabilities in the combustion chambers strongly influence optimal operating conditions. In coorperation with the partners of the first project phase (TP1 (Paschereit), TP2 (Janicka), TP4 (Bockhorn)) the generic burner configuration will be piloted such that the burner can be operated in the lean premixed regime. The impact of various parameters, i.e., the momentum, the temperature, the mixture of the unburnt gas, and the turbulence intensities of the nozzle boundary layer, on the acoustic emission of the turbulent flame will be investigated and will be quantified w.r.t. the acoustic field. The experiments conducted by TP1 (Paschereit) will be inves-tigated by large-eddy simulations by TP2 (Janicka) and TP4 (Bockhorn) to compute the resulting acoustic field in the present subproject TP3 (Schröder). Additionally, questions concerning the required numerical solution of the flame front for a correct acoustic simulation will be investigated in collaboration with TP2 (Janicka). Furthermore, a detailed evaluation of a direct numerical simulation by TP4 (Bockhorn) will significantly enhance the insight into the related acoustic source mechanisms using the source formulation from the acoustic perturbation equations.