Analysis of basic characteristics of air convection turbulence simulation device

Abstract

The random change of the atmospheric temperature field causes the fluctuation of the refractive index, which produces the optical turbulence effect. This will affect the results of atmospheric light transmission experiments. In order to study the effect of light transmission under different conditions, an air convection turbulence simulation device was developed. This device can simulate the turbulence field under different temperature conditions. The temperature pulsation method is used to measure the refractive index structure constant and one-dimensional temperature spectrum distribution inside the turbulence simulation device in detail under different temperature difference conditions. The results show that the refractive index structure constant distribution trend on the path of multiple measurements under the same conditions is relatively consistent. In general, the turbulence intensity on both sides is relatively large, and the middle is uniform. The range of equivalent coherence length generated on the optical transmission path is about 2.75cm~109.72cm. The outer scale is about 0.55m under the condition of 100 degrees Celsius temperature difference. The temperature fluctuation spectrum satisfies the -5/3 scale rate in the range of 0.3Hz~20 Hz. The basic turbulence characteristics simulated by this device are close to the actual atmospheric turbulence performance. It has the advantages of controllable experimental conditions, good repeatability and long-term stable operation, etc. Therefore, the device can be used for experimental research on light transmission under different turbulent conditions.