SU58211A1 - The method of determining the average speed of the river and other flow - Google Patents

Description

For the purposes of design, as well as for hydrological forecasts, it is often very important to know the time to move in on a particular section of the river or, equivalently, the average flow velocity on a given section (as applied to the determination of water flow). This task is solved with practically low accuracy by instrumental determination of speeds in individual cross sections, the use of floats, the movement of the flood wave, etc., which, of course, cannot always satisfy the request.

More perfect, according to the inventor, is his proposed method, based on the propagation of a sound wave in a stream and carried out in the following way.

In the upper section of the river, a shot, explosion or the like is produced, the sound wave of which in the water column spreads in all directions, including the lower section. Since there are many convolutions and obstacles along the river, the sound wave will have a complex trajectory. The time of the explosion and the time of arrival at the lower target of the first sound wave are recorded at the lower end by a light catcher and a sound absorber or other

in a way. After that, the trap is transferred to the upper end, and the sound source to the lower end and the operation is repeated. At the same time, the time Ti of the propagation of a sound wave down the river will be less than the time Ha of propagation of the sound wave up.

It is known that the speed of sound propagation in a medium depends on its composition, density, temperature, etc., and in this case, on the topography and configuration of the channel, which, of course, is not possible to take into account. But since these factors affecting the speed of sound, as well as the trajectory of the sound wave (no matter how zigzag it was), remain the same during the first and second tests, their influence is mutually exclusive from top to bottom. and from bottom to top will depend only on the flow rate.

7 4- G

The average time for the passage of a sound wave will therefore correspond to the passage of sound in standing water, all other conditions being equal.

The speed of propagation of a DOWN will be greater than the rate of propagation of sound from the lower to the upper range by twice the average velocity of the flow. "And this part xe, i.e., lv, IJ S whence V- (- (± - -2, where V is the average flow velocity, L is the length of the section along the flow axis. Since the speed is 3 (a sound wave in water significantly (more than in the air, i.e. 1400-1500 m / s, then the trap must be equipped with a high-precision clock mechanism that fixes hundredths of a second. By knowing the average flow velocity, it is easy to determine the average flow rate in this area according to the formula: Q vF, where F is the average area of the LIVE section. The value of the Average living section can be determined based on the volume W filled "o Doy channel, concluded between the top and m and lower sections, which is easy to find, having a plan with isobaths. The river section and the length of the section. The subject of the invention is a method for determining the average velocity of a river or another stream, characterized in that sound is oscillated at one point of the stream (e.g., by an explosion) in the stream and simultaneously measured at a second point 0, one hundred meters from the first distance , moment of explosion and moment of arrival of sound waves We measure the flow, and then repeat the operation, producing an explosion at the second point, and measuring at the first point, so that we can judge by the difference in the sound velocities obtained from the measured speed with.