大学物理 ›› 2008, Vol. 27 ›› Issue (5): 46-46.

• 著者文摘 • 上一篇    下一篇

研究温度波的传播特性

王喆[1] 苏为宁[2]   

  1. [1]南京大学匡亚明学院,南京210093 [2]南京大学物理系,南京210093
  • 出版日期:2008-05-25 发布日期:2008-05-20

Study on the decay characteristic of the thermal wave

  • Online:2008-05-25 Published:2008-05-20

摘要: 根据振动与波的原理,把样品上某点温度随时间的周期性变化看作一种振动,把这种温度变化向外传播的过程看作波动,引进温度波,说明样品上各点温度随时间、距离的变化;采用一维模型,写出温度波的传播方程.考虑到样品(铜棒)散热,引进衰减系数,描述温度幅度随频率及传播距离的变化关系.利用傅里叶变换分析实验数据,得到温度波幅度与角频率、位置的对应关系.根据温度幅度衰减公式拟合数据,算出基频及倍频对应的衰减系数.结果说明:衰减系数与温度波的频率相关,温度波的频率越高,衰减系数越大,温度幅度衰减得越快.

关键词: 一维热传导系统, 温度波, 傅里叶变换, 衰减系数

Abstract: The periodic variation of temperature of the sample with time is regarded as a vibration based on the principle of vibration and wave. The temperature disturbance traveling through the sample is regarded as a wave motion. The temperature wave is defined to express the temperature varied with time and position, one - dimensional model is adopted to represent the temperature wave equation. The decay coefficient is introduced into showing dispersion of the copper bar. The temperature amplitude varies with the frequency and the transmitting distance. The experimental data is analyzed by using the Fourier transform. We get the temperature wave ampli- tude corresponding to the frequency and position. According to the decay formula, we get the decay coefficients of the fundamental and multiple frequencies. There is a correlation between the decay coefficients and the frequency of temperature wave. The higher temperature wave frequencis,the bigger decay coefficientis, and the faster temperature wave amplitude decays.

Key words: one-dimensional thermal conductive system, temperature wave, Fourier transform, decay coefficient

中图分类号: 

  • O551.2