Electromagnetic Force Control System Of Turbulent Boundary Layer And Torpedo Model Drag Reduction Experiment

This paper based on the theory of electromagnetic fluid control, designs the electromagnetic force control system,with the processing of digital signal technology and the supply of switching power technology. The electromagnetic control experiments of torpedo drag model were made in large-scale pool.The electromagnetic force control system device of fluid boundary layer experimentalThe paper analyzes the mechanisms of span-wise Lorentz force reducing the fictional resistance, designs the electromagnetic force control system.The control power is designed with the experiment indicators and based on DSP 2812. The paper introduces the hardware and software design methods. Then we analyze the method of the electro-magnetic actuator and designed an electro-magnetic actuator matched with the torpedo model.The boundary layer of torpedo model drag reduction experiments.Experimental torpedo model is lm in length and 0.1m in diameter, the head is the hemisphere structure and the tail is vertebrae structure.The torpedo model was surface-mounted with an actuator and immerged into the test pool. The periodic change of electromagnetic force applied to the surface of the torpedo, then measured the drag of torpedo with the strain gauge.Experimental results show that:When the velocity of torpedo reached 0.5m/s and 7 V or 5 V applied to the electro-magnetic actuator, the span-wise Lorentz force did not affect the drag of torpedo. We analyzed the reasons, the fluid condition of torpedo was laminar flow state that the Lorentz force did not have the action of reducing drag.When the velocity reached lm/s, there was a significant effect on the torpedo drag, approximately reducing the drag of 17.47%.The experimental results successfully show that the span-wise Lorentz force can significantly reduce the drag and also prove the applicability and reliability of the electromagnetic force control system.