Generator utilizing fluid-induced oscillations

Abstract

An electrical generator including a magnetic field generator and at least one energy converter for converting energy present in fluid flows into vibrations or oscillations. The converter includes a flexible membrane having at least two fixed ends. The membrane vibrates when subject to a fluid flow. One of the electrical conductor and the magnetic field generator is attached to the membrane and configured to move with the membrane. The vibration of the membrane caused by the fluid flow causes a relative movement between the electrical conductor and the applied magnetic field. The relative movement causes a change in the strength of the magnetic field applied to the electrical conductor, and the change in the strength of the magnetic field applied to the electrical conductor induces a current flowing in the conductor.

1 . A method for modifying the performance of an electrical generator in response to environmental conditions comprising the steps of:
 providing a flexible thin membrane defining a central axis and having at least two fixed ends;   allowing the membrane to vibrate when subject to a fluid flow substantially transverse to the central axis;   providing an electrical conductor, providing a magnetic field generator that applies a magnetic field to the electrical conductor, and attaching one of the electrical conductor and the magnetic field generator to the membrane;   detecting the speed of the fluid flow;   adjusting the membrane based upon the detected speed of the fluid flow.   
     
     
         2 . The method of  claim 1 , wherein the step of allowing the membrane to vibrate when subject to a fluid flow includes allowing the membrane to aeroestatically flutter when subject to the fluid flow. 
     
     
         3 . The method of  claim 1 , wherein the step of detecting the speed of the fluid flow includes the step of detecting and comparing the voltage generated by the electrical generator. 
     
     
         4 . The method of  claim 1 , wherein the step of adjusting the membrane includes adjusting the tensioning of the membrane. 
     
     
         5 . The method of  claim 4 , wherein the step of adjusting the tensioning of the membrane includes the step of adjusting the tension of the membrane if the detected speed of the fluid flow is greater than a predetermined value. 
     
     
         6 . The method of  claim 5 , wherein the step of adjusting tensioning of the membrane includes reducing the tension of the membrane. 
     
     
         7 . The method of  claim 4 , wherein the step of adjusting tensioning of the membrane includes maintaining a predetermined tension in the membrane. 
     
     
         8 . The method of  claim 7 , wherein the step of adjusting tensioning of the membrane includes the steps of providing a constant force mechanism, coupling the constant force mechanism to the two fixed ends of the membrane, and allowing the constant force mechanism to maintain a predetermined tension in the membrane. 
     
     
         9 . The method of  claim 8 , wherein the step of providing a constant force mechanism includes the step of providing a constant force spring. 
     
     
         10 . The method of  claim 1 , wherein the step of adjusting the membrane includes twisting the membrane. 
     
     
         11 . The method of  claim 10 , wherein the step of twisting the membrane includes twisting the entire membrane. 
     
     
         12 . The method of  claim 10 , wherein the step of twisting the membrane includes twisting the membrane if the detected speed of the fluid flow is greater than a predetermined value.