Modeling and Sliding Mode Control of Rotating Helical Pump

Two-phase fluids transportation is very important in industry. Rotating helical pump is a special form that can be used to transfer fluid-gas flows and also to generate pulsatile flows. The structure of this pump differs from conventional pumps and its geometry can be changed during operation. In this paper, while demonstrating a fabricated second version of the rotating helical pump, a dynamic analysis is performed for the first time and the governing equations are extracted based on the input control variables (rotational speed and tilt angle of the pump). In the dynamical analysis, a rotating control volume corresponding to a spiral tube is considered. In order to determine the values of the inputs corresponding to the desired outputs, we use the non-dimensional characteristic curves of the pump that was published in the previous study. Then the control is performed on the basis of two input variables to reach the desired pump head and flowrate. A sliding mode controller is implemented. The results are shown for the desired value of head and flowrate. The attractive features of this pump are that it can work with the low rotational speed, and it can change the point of operation (head-flowrate) without changing the speed (just with changing the tilt angle). The results include governing equations of the rotatical helical pump that can be used in future studies. Moreover, the results show the success of the sliding mode method in control of the pump.