| 摘要 |
PROBLEM TO BE SOLVED: To limit the wind velocity disturbance to be measured to the minimum limit by calculating the difference of ultrasonic wave propagating times of forward and reverse directions as three-dimensional components of the wind velocity, and reducing the cost of the entire measuring system. SOLUTION: An ultrasonic transceiver 11 is disposed perpendicularly to its normal N, and ultrasonic transceivers 12 to 14 and disposed at an equal interval on the circumference of a virtual circle C having a center O for passing the normal N. The transceiver 11 has wide directivity, and propagating passages R12 to R14 are formed to the transceivers 12 to 14. A wind velocity calculator 20 propagates the ultrasonic wave forward on the passage 12, and detects a prescribed time from the transmitter 11 to the receiver 12 as a forward propagating time. Then, a reverse propagating time on the passage R12 is detected, the difference of the both is detected to calculate the three-dimensional components V12 of the velocity on the passage R12 . Similarly, the Three- dimensional components V13 , V14 of the velocities on the passages R13 an R14 are detected, and the components of the orthogonal three-axes directions of the wind velocities are calculated. |
