Theoretical Analysis On Dynamic Characteristics Of Pulsating Flow Hydranlic Impact System

In this paper, the principle of pulsating flow hydraulics and the background of the project—impact coal cutter were introduced at first. By analyzing the principle of the impact coal cutter, a experimental system of one phase pulsating flow hydraulic impact system was built. Through simplifying the system, the bond graph of the system was got by means of power bond graph, and the mathematical model, i.e. state equation, was got too. In terms of the mathematical model, the simulation model, including impact section model and temperature model, were built by use of the software MATLAB/Simulink. After setting the system parameters and simulation parameters, run the simulation model in the initial masked parameters. The variable dynamic characteristic curves of pressure, position and velocity were achieved. At last, changing the parameter values of impact frequency, the diameter of the tube, the length of the tube, etc of the system, the dynamic curves characteristic were derived in the different parameter values. The reflection regularities of those parameters on the dynamic characteristics of the system were found. Through the data statistics and calculation, the curves of the relations between these parameters and efficiency were drawn. Meanwhile, after simulating the temperature model, the temperature curves were also achieved in different impact frequencies and tube diameters. From the curves, the key factors that influenced the temperature most were analyzed so that we can take effective measures to ensure that the system worked in the normal temperature if the temperature was so high. The results of the research will be not only useful to extending the utility fields of pulsating flow hydraulics, but also provide some theoretical bases for the design and analysis of pulsating flow hydraulic impact system.