直升机辐射噪声是水下探测直升机的基础。讨论了直升机辐射声场指向性、频率特性及空气声向水下传播特性。结果表明,空气声入水折射波在水下传播具有余弦指向性特性,远距离传播损失与海底类型有关,与声源高度关系不大。最后分析了水下对直升机噪声的探测能力,结果表明水下探测直升机可行。 Helicopter radiation noise is the basis for underwater exploration helicopters. Discusses helicopter radiation field directivity, frequency characteristics and airborne acoustic underwater propagation characteristics. The results show that the refracted wave of air-infiltrated water has the characteristic of cosine directivity in underwater propagation. The long-distance propagation loss is related to the seafloor type and has little to do with the sound source height. Finally, the underwater helicopter noise detection capability is analyzed. The results show that underwater detection helicopters are feasible.