Peak ultrasound echo intensity

In many engineering applications, gas-liquid flows of larger gas void fractions are encountered. In the next section, a method is described that makes use of the peak ultrasound echo intensity to detect the location of the gas-liquid interface in such flows. 

GAS-LIQUID INTERFACE INFERRED FROM THE PEAK ULTRASOUND ECHO INTENSITY... 

In this section, the peak ultrasound echo intensity is used to locate the position of the gas-liquid interface flowing in a horizontal pipe. The accurate detection of the gas-liquid interface in pipe flow has important implications in engineering. 

Second, a peak-intensity ultrasound echo can be used to detect the gas-liquid interface, but in this case the aim is the development of a flow meter capable of estimating the ratio of component phases accurately and in real time. Our results are promising for the estimation of the liquid flow rate of gas-liquid two-phase flow further research will produce valuable data that will allow the estimation of flow rates for the two phases simultaneously. The results presented here show the liquid flow rate estimated by the peak echo intensity method can provide an accurate estimate of the actual liquid flow rate. This method can be applied to pure liquid as well as to a two-phase flow where the void fraction is as high as 50%. The flows tested are of the stratified, elongated bubble, and slug flow types. Other types of flow such as wave flow and dispersive flow were not tested the present experimental setup does not provide the gas and liquid flow rates needed to achieve such flows. 

Ultrasound-based Gas-liquid Interface Detection in Gas-liquid Two Phase Flows (by Prof. Yasushi Takeda et al.) introduces two ultrasonic-based detection methods for gas-liquid interface of gas-liquid two-phase flows in horizontal pipes, based on ultrasonic velocity profiler (UVP) measurements. One approach using ultrasonic peak echo intensity information to predict gas-liquid interface has wider application range and has been validated. Another approach based only on liquid velocity information is a relatively new technique and is still at intermediate stage of an ongoing development. 

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