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，该系统能够在考虑传感器数量较少的情况下最准确地确定由径向压缩机发射到连接的流量排放管中的声功率。与DIN EN ISO 5136方法（风机声功率级在第三倍频程内估算）不同，本文开发的测量系统在确定离心式压缩机发出的音调声功率分量方面具有更高的精度。此外，在特定的叶片通过频率的感应模式场的一个很好的估计将实现。与使用横向管道部分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进径流式压缩机声学研究领域，降低固定式压缩机设施的噪声排放。项目第二阶段的目标是通过实验证明两个测量系统的适用性，这两个测量系统是在项目第一阶段开发并在虚拟环境中进行测试的。为此，测量系统将在亚琛RWTH的径向压缩机设施中实施。应用项目第二阶段的实验获得的音调声功率和项目第一阶段的数值计算的音调声功率的比较将确定哪一个开发和实施的方法更好地执行，从最终的测量系统将被导出。进一步将数值研究和测量方法的发展推广到考虑叶片扩压器的径向压气机。

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.