What is the equation and units for liquid flow rate

The equation for flow rate is:

Q=Sv=constant. (S is the cross-sectional area, v is the velocity of water flow) (fluid mechanics commonly used Q = AV)

Incompressible fluid through the same flow tube for constant flow, each moment of the flow tube of each cross-section of the flow rate is the same.

The measurement of the flow rate of a fluid flowing in a certain channel is collectively referred to as flow metering. Flow measurement of the fluid is diverse, such as the measurement object has a gas, liquid, mixed fluids; fluid temperature, pressure, flow are large differences, the requirements of the measurement accuracy is also different.

Expanded

The development of flow measurement can be traced back to the ancient water conservancy projects and urban water supply system. The ancient Roman Caesar era has been used orifice plates to measure the amount of drinking water for residents. Around 1000 BC ancient Egypt used the weir method to measure the flow of the Nile River. China's famous Dujiangyan water conservancy project application of the water level of the mouth of the bottle to observe the size of the water and so on. 17th century Torricelli laid the theoretical basis for differential pressure flowmeter, which is a milestone in the flow measurement.

Since then, the 18th and 19th centuries, many types of flow measurement instrumentation prototype began to take shape, such as weir, tracer method, Pitot tube, venturi, volumetric, turbine and target flowmeter.

The 20th century due to the process industry, energy measurement, urban utilities on the flow measurement of the demand for the rapid growth of the instrument to promote the rapid development of microelectronics and computer technology, the rapid development of the instrument greatly promote the replacement of new types of flowmeters such as the emergence of new flowmeter like a spring. So far, it is said that there are hundreds of flowmeter to the market, the field use of many difficult problems can be expected to be solved.

China to carry out modern flow measurement technology is relatively late, the early required flow meter are imported from abroad.

Flow measurement is the study of material quantitative change in science, the law of mass reciprocal change is the basic law of the development of things connected, so its measurement object is not limited to the traditional sense of the pipeline liquid, wherever there is a need to grasp the quantitative change of the place have the problem of flow measurement. Flow and pressure, temperature and listed as the three major detection parameters.

For a certain fluid, as long as we know these three parameters can be calculated with its energy, in the measurement of energy conversion must be detected in these three parameters. Energy conversion is the basis of all production processes and scientific experiments, so the flow and pressure, temperature instrumentation as the most widely used.

Baidu Encyclopedia - Liquid Flow Meter

Baidu Encyclopedia - Flow Rate