波数
决定波的空间周期性的一个量（即波形重复自身所需的距离） —
\begin{align} \label{eq:12601a} k_w &= \frac {2 \pi \,f}{C} \\[0.7em]%eqn_interline_spacing &= \frac {2 \pi}{\lambda} \nonumber \end{align}
其中 —
| \( k_w \) | = 波数 |
| \( f \) | = 振动频率 |
| \( C \) | = 波速 |
| \( \lambda \) | = 波长 |
波速 \( C \) 必须与所评估的波的类型相适应。例如：
参考文献：Kinsler，第 36 页
Wave number
A number that determines the spatial periodicity of a wave (i.e., the distance required for a wave shape to repeat itself) —
\begin{align} \label{eq:12601a} k_w &= \frac {2 \pi \,f}{C} \\[0.7em]%eqn_interline_spacing &= \frac {2 \pi}{\lambda} \nonumber \end{align}
where —
| \( k_w \) | = wave number |
| \( f \) | = frequency of oscillation |
| \( C \) | = wave speed |
| \( \lambda \) | = wavelength |
The wave speed \( C \) must be appropriate for the type of wave that is being evaluated. Examples:
- For a pressure wave in a thin rod, the thin-wire wave speed \( c_{tw} \) must be used.
- For a pressure wave in an infinite medium, the dilatational wave speed \( C_{d} \) must be used.
Reference: Kinsler, p. 36