空气、水和其他介质中的声速
不同温度下空气、水、钢材和其他材料等各种介质中的声速。
概述
声速是压力扰动在介质中传播的速率。它depends on the elastic properties and density of the material. In gases it rises with temperature; in liquids and solids the relationship is governed by bulk modulus. Understanding sound speed is critical for acoustics, ultrasonics, aerodynamics, and underwater communication systems.
关键公式
理想气体中的声速
其中 为比热比， 为比气体常数， 为 absolute temperature in kelvin.
液体和固体中的声速
其中 为体积模量（或固体的弹性模量）， 为质量密度ity.
General Relationship
频率乘以波长等于传播速度。
变量
| 符号 | 说明 | Typical Unit |
|---|---|---|
| Speed of sound | m/s | |
| Specific heat ratio (1.4 for air) | — | |
| Specific gas constant | J/(kg·K) | |
| Absolute temperature | K | |
| Bulk modulus / elastic modulus | Pa | |
| 密度 | kg/m³ | |
| Frequency | Hz | |
| Wavelength | m |
Speed of Sound in Common Media
温度 (°C) | 声速 (m/s) | |
|---|---|---|
| Air (dry, 1 atm) | 0 | 331 |
| Air (dry, 1 atm) | 20 | 343 |
| Air (dry, 1 atm) | 100 | 386 |
| Carbon dioxide | 0 | 259 |
| Helium | 0 | 1007 |
| Hydrogen | 0 | 1270 |
| Water (fresh) | 20 | 1481 |
| Water (sea) | 20 | 1522 |
| Ethanol | 20 | 1162 |
| Mercury | 20 | 1450 |
| Aluminum (longitudinal) | 20 | 6420 |
| Steel (longitudinal) | 20 | 5960 |
| Glass (borosilicate) | 20 | 5640 |
| Rubber (hard) | 20 | 1560 |
| Wood (soft, along grain) | 20 | 3800 |
来源: engineeringtoolbox.com
Temperature Effect on Speed in Air
速度 of 声音 in 空气 vs 温度
水中声速与温度
温度 (°C) | 淡水 (m/s) | 海水 (m/s) |
|---|---|---|
| 0 | 1402 | 1449 |
| 5 | 1426 | 1471 |
| 10 | 1447 | 1490 |
| 15 | 1466 | 1507 |
| 20 | 1481 | 1522 |
| 25 | 1497 | 1535 |
| 30 | 1509 | 1546 |
| 40 | 1529 | 1565 |
| 60 | 1551 | 1593 |
来源: engineeringtoolbox.com
Calculator — Speed in Dry Air
速度 of 声音 in Dry 空气
单位换算器
声音 速度 单位 转换器
Subsonic and Supersonic Speed
如果马赫数低于 1，流速低于当地声速， speed is subsonic. If the Mach number is 1, the speed is transonic. If the Mach number is above 1, the flow velocity is higher than the speed of sound and the speed is supersonic.
还原的原始源表
以下表格还原自原始来源页面，以保留完整的参考数据。
一些常见物质的体积模量和密度
体积模量 - K - (109 N/m2) | 密度 - ρ - (kg/m3) | |
|---|---|---|
| Water (10 oC) | 2.09 | 999.7 |
| Oil | 1.35 | 920 |
| Ethyl Alcohol | 1.06 | 810 |
| Mercury | 28.5 | 13595 |
来源: engineeringtoolbox.com
原始源图
The following original source image is preserved to avoid losing visual reference material.
工程要点
- 空气中温度主导。 粗略经验法则：声速大约增加0.6 m/s for every 1 °C rise in temperature. Humidity has a minor secondary effect (~0.1–0.5 % variation).
- 压力对理想气体中的声速直接影响可忽略，因为密度和and bulk modulus scale proportionally with pressure, cancelling out. The dominant variable is temperature.
- 在水中，盐度、温度和压力（深度）都会显著影响声速。Underwater acoustic models such as UNESCO's Chen-Millero equation account for all three variables.
- 在固体中，波的类型很重要。上面显示的纵波（P 波）速度高于than shear (S-wave) speeds. Surface (Rayleigh) and plate (Lamb) waves travel at still different rates.
- 音爆和马赫数。 当地声速定义了mpressible flow. An object moving at Mach 1.0 creates a shock wave whose geometry depends directly on the ambient sound speed.
- 医用超声。 软组织成像假定平均速度为 1540 m/s。assumed speed cause blurring and misregistration in ultrasound images.
- 马赫锥角由 给出，其中 Ma 为马赫数。gher altitudes, lower temperature reduces the speed of sound and widens the cone for the same airspeed.
参考资料
- Engineering Toolbox — 声速
- Kinsler, L. E., et al., Fundamentals of Acoustics, 4th ed., Wiley.
- UNESCO, Algorithms for Fundamental Properties of Sea Water, Technical Papers in Marine Science.