Abstract: It is necessary to measure and analyze the background noise of aero-acoustic wind tunnel in order to reduce its sound pressure level (SPL). In this paper, the measurement scheme and frequency spectrum analysis of a 0.55m×0.4m aero-acoustic wind tunnel are introduced. According to the acquired data, the power spectrum density is obtained by means of the average periodic diagrams, and the result is comprehensively analyzed. The result of measurement shows that the SPL of the background noise is 78.15dB when the wind speed in the open-jet test sections is 80m/s.

Key words: acoustics, acoustics measurement, aeroacoustic wind tunnel, spectrum analysis, average periodic diagrams, background noises

摘要： 为了降低航空声学风洞背景噪声的声压级水平，有必要对风洞背景噪声进行测试和分析。针对0.55 m×0.4 m航空声学风洞，介绍风洞背景噪声的测试方案及频谱分析。利用计算机采集得到的试验数据，使用平均周期图法计算噪声自功率谱密度，对测试结果进行详细分析。测试结果表明：风洞开口试验段风速为80 m/s时，背景噪声声压级为78.15 dB。

关键词: 声学, 噪声测量, 航空声学风洞, 频谱分析, 平均周期图, 背景噪声