Research On Fluid Transients In Water Hydraulic Pipeline

Water hydraulics is gathering peoples’ more and more attention as the following benefits: safe, fireproof and environmental harmless. In the field of fluid transmission, the sudden closure of a valve or the shutdown of a pump may lead to fluid transients which involved in huge pressure vibrations. Fluid transients and their subsequent cavitation phenomenon may damage the pipeline and the valve. Owing to physical characteristics difference between water and oil, fluid transients happened in water hydraulic pipeline is different from what happened in traditional oil hydraulic pipeline, which requires further investigation.This topic is aiming to carry on simulation and experimental research on fluid transients in water hydraulic pipeline. The main contents are as follows:1. Based on the continuity equation and the motion equation of fluid dynamics to build the mathematical model of fluid transients happened in one-dimensional horizontal placed water pipeline.2. Using MATLAB/Simulink software and finite difference method to carry out simulation analysis on the proposed mathematical model, acquiring pressure pulsation simulation curve of different location in the pipeline and different initial flow speed. Using genetic algorithm to carry out dynamic friction parameter identification process, the identified results can make simulation curve more fit to the experimental curve.3. Design and build experimental testing platform, the validity of the self- made rapid shut-off electromagnetic valve is theoretically verified using JMAG finite element simulation software. The testing program and testing procedures are also drawn up.4. Carry out water hydraulic fluid transient experiment verifying test with different initial flow conditions, acquiring pressure pulsation curve and high speed camera video of cavitation. Building simulation model of cavitation taken into consideration, making comparison between simulation curve and the experimental curve.There are several innovation points. The fitness function in genetic algorism is determined by the difference of peaks of simulation and experimental curve, which achieved a good result. The self-made rapid shut-off electrical magnetic valve makes the experimental testing more facilitate and its validity is verified by both theoretical analysis using JMAG software and real test.