Wind speed refers to the distance the wind travels in a certain period of time; wind refers to the strength of the wind when it hits an object. There is no grade level for wind speed, only wind power is graded. Wind power is generally graded according to wind speed. Generally speaking, the lower the wind speed, the lower the wind level, the weaker the wind’s rupture power. Conversely, the higher the wind speed, the higher the wind level, the stronger the wind’s tetanic power.
Wind speed and wind force are important indicators analyzed by the Meteorological Bureau, and they are also key factors that they attach importance to. It not only has a great impact on people’s daily life, but also has important significance for the research work of the Meteorological Bureau and the voyage to sea. Therefore, the use of wind speed and direction sensors helps the smooth development of various social activities. According to the principle of measurement, I will explain the following methods for everyone: traditional measurement, mechanical measurement, ultrasonic measurement, etc.
Traditional measurement methods
Wind direction measurement: use wind vane
The direction of the wind direction arrow of the pair of weather vanes indicates which direction the wind was blowing at that time. When the wind vane and the air flow path form a certain angle, the air flow will cause a pressure on the wind vane tail. Its size is proportional to the projection of the geometric shape of the wind vane on the vertical plane of the airflow direction. The wind vane head has a small windward area and the tail wing has a large windward area. The wind pressure caused by this pressure difference causes the wind vane to rotate around a vertical axis until the wind vane is parallel to the airflow. The wind direction can be easily observed from the position of the weather vane and the fixed main azimuth indicator rod.
Mechanical measurement
The mechanical crosswind is like a wind meter to measure the wind, and the appearance looks like a mechanical watch. It is usually used to measure wind in wells. The wind speed needs to be estimated first, and then use the wind vane and stopwatch to reset the pointer of the wind meter and the stopwatch to zero, and then make the wind meter face the wind flow and be perpendicular to the direction of the wind flow. After the wind meter idling for 30 seconds, turn on the wind speed meter and stopwatch switches at the same time to start the measurement. It should be noted that the number of wind measurements on the same section is not less than 3 times, and the wind measurement process should be carried out steadily. For example, wind speed and wind direction sensors use common mechanical wind measurement methods to make better use of wind energy to generate electricity and support the development of new energy wind power technology.
Ultrasonic velocimetry
The principle of ultrasonic wind measurement is to measure wind speed and direction through the ultrasonic time difference method. Due to the spreading rate of the sound in the gas, it will be superimposed with the airflow velocity in the wind direction. If the ultrasonic wave’s propagation path is the same as the wind direction, its speed will accelerate; on the contrary, if the ultrasonic wave’s propagation path is opposite to the wind direction, its speed will slow down. Therefore, under a fixed measurement premise, the spreading rate of ultrasonic waves in the air can correspond to a function of wind speed. The wind direction and wind speed can be obtained by calculation.
