Tangential force panel for active flow control of a conductive fluid

Abstract

Magnetic and electric fields are used in a controlled manner to create equal and oppositely-directed Lorentz forces tangential to the surface of a control tile that affect the flow of a conductive fluid near the boundary layer of the control tile, or a matrix of control tiles, immersed in a conductive fluid. The control tiles are combined to form control cells, with each control cell including a pair of electrodes and at least one permanent magnet. The pair of electrodes are coupled to a current source which biases the electrodes to cause an electrical current to flow from a positive electrode (anode), through the conductive fluid in which the cell electrodes are immersed, to a negative electrode (cathode). The current source may be time multiplexed to better control the direction of the current flow between adjacent electrodes. The permanent magnet generates a magnetic field which is positioned to interact with the electrical current where the magnetic field is strongest, thereby creating a strong tangential Lorentz force. Such force influences the flow of the conductive fluid, near the boundary of the control tile, e.g., reduces drag of the fluid as it flows over the tile surface. The invention may be used, e.g., within the hull of an ocean-going ship to reduce the drag of the sea water passing over the surface of the hull.