Development and validation of a measurment procedure to determine the radiated sound power of a radial compressor

本项目的主要任务是开发一种测量系统，该系统能够在低传感器数量的情况下最准确地确定径向压缩机向连接的流量排放管发射的声功率。该测量系统将有助于进一步研究声发射声场的影响因素，并评估减少声发射的不同方法。与DIN EN ISO 5136方法（风扇声功率级在第三个八度频带估计）相反，这里开发的测量系统在确定径向压缩机发出的音调声功率成分方面具有更高的精度。此外，还可以很好地估计出特定叶片通过频率下的感应模场。与使用横贯管道截面进行的高分辨率测量相反，手头的测量系统基于简单，坚固和低成本的设计，使其适用于较小的研究小组。提供测量系统的长期目标是推动径向压缩机声学研究领域的发展，并减少固定压缩机设施的噪声排放。所要求的第二个项目阶段的目标是对两个测量系统的适用性进行实验证明，这两个测量系统在第一个项目阶段的虚拟环境中开发和测试。为此，测量系统将在亚琛工业大学的径向压缩机设施中实施。将项目二期应用的实验获得的音调声功率与项目一期的数值计算的音调声功率进行比较，将确定开发和实施的方法中哪一种表现更好，并由此推导出最终的测量系统。进一步将数值研究和测量方法的发展扩展到考虑叶片扩散器的径向压气机。

The primary task of the present project is to develop a measurement system capable of determining most accurately the sound power emitted by a radial compressor into the connected flow discharge pipe considering a low sensor count. This measurement system will help future studies to investigate the influencing factors in the emitted tonal sound field and evaluate different approaches to reduce sound emissions.In contrary to the DIN EN ISO 5136 Method (the fan sound power levels are estimated in third octave bands) the measurement system developed here will have a higher accuracy in the determination of the tonal sound power components emitted by the radial compressor. Furthermore, a good estimation of the induct mode field at specific blade passing frequencies will be achieved. Opposed to high resolution measurements conducted by using traversal duct sections the measurement system at hand is based on an easy, robust and low cost design making it accessible for smaller research groups. The long term goal by providing the measurement system is to advance the research field of radial compressor acoustics and to reduce the noise emissions of stationary compressor facilities.The goal of the requested second project phase is the experimental proof of applicability of two measurement systems, which were developed and tested in a virtual environment in the first project phase. To do so, the measurement systems will be implemented at the radial compressor facility of the RWTH Aachen. A comparison of the experimental obtained tonal sound power of the applied project phase II and the numerical computed tonal sound power of project phase I will determine which of the both developed and implemented methods preform better, from which the final measurement system will be derived. Furthermore the numerical study and the development of the measurement methods are extended to the radial compressor considering a vaned diffusor.