Optimized accelerator-extractor pairs for fluid power generation

Abstract

A device includes an extractor structurally configured to extract energy from a fluid flow, an accelerator structurally configured to accelerate a fluid stream through the extractor thereby creating an accelerated fluid stream, and an extractor feature structurally configured to minimize blockage of the accelerated fluid stream. The extractor feature may include one or more of a linear cascade, an oscillating foil, and an axial extractor.

What is claimed is: 
     
         1 . A device comprising:
 an extractor structurally configured to extract energy from a fluid flow;   an accelerator structurally configured to accelerate a fluid stream through the extractor thereby creating an accelerated fluid stream; and   an extractor feature structurally configured to minimize blockage of the accelerated fluid stream, the extractor feature including one or more of a linear cascade, an oscillating foil, and an axial extractor.   
     
     
         2 . The device of  claim 1  wherein the extractor feature is structurally configured to minimize individual extraction plane flow effects by reducing individual plane solidity. 
     
     
         3 . The device of  claim 2  wherein the extractor feature includes the linear cascade, the linear cascade including two or more co-planar blades and a stage solidity of less than 20%. 
     
     
         4 . The device of  claim 2  wherein the extractor feature includes the oscillating foil, the oscillating foil including two or more co-planar foils and a stage solidity of less than 20%. 
     
     
         5 . The device of  claim 2  wherein the extractor feature includes the axial extractor, the axial extractor including two or more co-planar collapsible foils and a stage solidity of less than 20%. 
     
     
         6 . The device of  claim 1  wherein the extractor feature is structurally configured to minimize blockage by minimizing flow effects engendered by power extraction. 
     
     
         7 . The device of  claim 6  wherein the extractor feature extracts power from a mono or bidirectional radial motion. 
     
     
         8 . The device of  claim 7  wherein the mono or bidirectional radial motion includes a linear cascade. 
     
     
         9 . The device of  claim 6  wherein the extractor feature extracts power from an axial motion. 
     
     
         10 . The device of  claim 9  wherein power from the axial motion is extracted by one or more of a piston and collapsible kite configuration or an electrostatic system. 
     
     
         11 . The device of  claim 6  wherein the extractor feature extracts power from a combination of axial and radial motion. 
     
     
         12 . The device of  claim 11  wherein the combination of axial and radial motion is caused by one or more of an oscillating foil or an unsteady aerodynamics configuration. 
     
     
         13 . The device of  claim 1  wherein the extractor feature is structurally configured to extract power from a volume by utilizing multiple extraction planes. 
     
     
         14 . The device of  claim 1  wherein the extractor feature is structurally configured to minimize flow effects by minimizing a size of one or more extractor elements relative to boundaries of the accelerator and other extraction planes. 
     
     
         15 . The device of  claim 14  wherein the flow effects include wakes. 
     
     
         16 . The device of  claim 1  wherein the extractor feature is structurally configured to reduce individual plane solidity to minimize individual extraction plane flow effects. 
     
     
         17 . The device of  claim 1  wherein the extractor feature is structurally configured to limit flow effects to an outside of a swept area by increasing a number and reducing a size of one or more extractor elements. 
     
     
         18 . The device of  claim 1  wherein the extractor feature is structurally configured to counterbalance effects to an outside of a swept area in at least one of a two-dimensional or three-dimensional anhedral configuration thereby reducing one or more of a tip leakage or a tip vortex expansion angle. 
     
     
         19 . The device of  claim 1  wherein the extractor feature is structurally configured to minimize blockage between extractor elements by changing a geometry of an extractor blade row from a nozzle to one or more of a tube or diffuser configuration that utilizes an axial offset in one or more of a spiral or angled configuration.