摘要:
针对海中声源在海-气界面低频异常声透射问题,根据两层媒质声传输模型,分析了大气声速和密度与气压、气温、湿度及海水中声速和密度与海温、盐度间的关系,研究了低频声透射和传输受温度、气压、盐度、湿度等因素的影响,分析了各因素对声透射和传输的影响程度。结果表明:1)声透射到大气中的声功率与气温、湿度负相关,与海温、盐度、气压正相关;2)单极子与水平偶极子声源辐射到海中的声功率与海温、盐度负相关,而垂直偶极子声源辐射到海中的声功率与海温、盐度正相关;3)声透射指向性与海温正相关,与气温负相关;4)低频声透射受温度影响最大,其次是盐度,受气压和湿度影响较小,垂直偶极子声源的声透射受温度影响大于水平偶极子和单极子声源。
Abstract:
In view of low frequency abnormal sound transmission of sound source in the sea at the sea-air interface, according to the two-layer medium sound transmission model, we analyze the relationships of the sound speed and the density of the atmosphere with the atmospheric pressure, the air temperature, the humidity;we also analyze the relationships of the sound velocity and the density of seawater with the sea surface temperature (SST) and salinity;we investigate the low-frequency abnormal sound transmissions influenced by temperature, pressure, salinity, humidity and other environmental factors;we analyze the influences of various factors on the sound transmission. The obtained results are as follows. 1) the sound power in the air, obtained by the sound transmission of sound source in the shallow sea, is negatively correlated with atmospheric temperature and humidity, and positively correlated with the SST, salinity, and atmospheric pressure. 2) The sound power that is radiated into the sea by the monopole and horizontal dipole source at the sea, is negatively correlated with SST and salinity, while the sound power that is radiated into the sea by the vertical dipole sound source, is positively related to SST and salinity. 3) The sound transmission directivity is positively related to SST and negatively correlated with atmospheric temperature. 4) The air temperature and SST have the greatest influence on low-frequency abnormal sound transmission, while the effects of air pressure and humidity on them are smaller than that of salinity. The effect of temperature on the low frequency abnormal sound transmission of vertical dipole sound is greater than those of the horizontal dipole and a monopole sound source.