This device can simultaneously complete three levels of teaching tasks: qualitative demonstration, quantitative measurement, and design experiments in the same self circulating pipeline, helping students intuitively understand and verify the Bernoulli equation (energy equation) as well as core concepts such as energy loss and flow velocity distribution. Usage scenario: Group experiments for courses in fluid mechanics, thermal power, water supply and drainage, construction and environmental protection in universities/vocational schools; Fluid system awareness training for pump and valve manufacturers, architectural design institutes, etc; The interactive demonstration of the Bernoulli phenomenon in the science popularization exhibition hall shows that the faster the flow rate, the lower the pressure.