The Design Of Air-water Physical Measurement Sensor

The measurement of cloud liquid water cotent is an indispensable part in the weather modification and cloud physics research. It may have significant application in improving the capability of meteorological observation and disater warning. Under normal circumstances, an important condition for the operation of weather modification is that whether there is sufficient liquid water in the cloud. Water content is one of the most important parameters to measure the regional potential of artificial rainfall and the selection of rainfall operating condition. Therefore, the real-time measurement of water content is a very important part of the cloud physics and weather modification. Traditional cloud liquid water sensors are relatively bulky and feature high power consumption. A miniaturized cloud liquid water sensor which is used to measure the cloud liquid water in strong convective weather is proposed.In this thesis, by utilizing the theoretical analysis and the finite element simulation, the temperature distribution of sensor is simulated under the influence of liquid water evaporation and pneumatic flow. The relationship between the heating power requirement and the cloud water content is obtained. The feasibility of the sensor design is verfied.In order to measure the magnitude of the cloud water content per unit volume accurately, the system of a miniaturized cloud liquid content sensor is designed. It uses MSP430F149as the primary controller device. RS232communication protocol can achieve the goal of system data communication. Moreover, a PID algorithm is employed to control the temperature of the sensor windward side. The fluctuation of the temperature can be controlled with a range of±0.3℃.The design and experiment results show that the sensor measured value is0.37g/m3when cloud liquid water content is0.4g/m3. At the same time, the sensor consumes only3.32W power. Experimental results show that the sensor possesses the advantages of small dimensions, light weight, low power consumption. Potentionally, it can be used to measure the cloud liquid water content in the convective weather.