Pressure Based Load Measurement

Abstract

A system and method for a pressure based load measurement system are provided. The system includes two pressure orifices arranged on a top surface and a bottom surface of an airfoil. The pressure differential between these two points is determined and an estimate of the aerodynamic load generated by the airfoil is determined from a linear correlation between pressure differential and load. The location of the orifices may be optimized using analytical or experimental techniques and a least squares empirical curve fit may be used to fit the data collected.

1 . A method comprising:
 determining, by a computing device having at least one processor, a pressure differential between a first pressure location and a second pressure location on an airfoil; and   determining, by the computing device, an aerodynamic lift force associated with the airfoil based on at least one non-pressure differential parameter and only pressure differential data corresponding to the pressure differential between the first pressure location and the second pressure location.   
     
     
         2 . The method of  claim 1 , further including identifying an optimum location for the first pressure location and the second pressure location. 
     
     
         3 . The method of  claim 2 , wherein the step of identifying the optimum location for the first pressure location and the second pressure location includes using at least one of analytical or experimental methods. 
     
     
         4 . The method of  claim 2 , wherein the step of identifying the optimum location for the first pressure location and the second pressure location includes identifying the first and second pressure locations based on a geometry of the airfoil. 
     
     
         5 . The method of  claim 1 , wherein the at least one non-pressure differential parameter includes wind speed. 
     
     
         6 . The method of  claim 1 , wherein the at least one non-pressure differential parameter includes barometric pressure. 
     
     
         7 . The method of  claim 1 , wherein the at least one non-pressure differential parameter includes rotor speed. 
     
     
         8 . The method of  claim 1 , wherein the at least one non-pressure differential parameter includes air density. 
     
     
         9 . The method of  claim 1 , wherein the at least one non-pressure differential parameter includes temperature. 
     
     
         10 . The method of  claim 1 , wherein the airfoil is at least one of an airplane wing, helicopter rotor, wind turbine blade, automobile spoiler and ship rudder. 
     
     
         11 . The method of  claim 1 , further including adjusting at least one of a geometry, position and flow control device of the airfoil based on the determined aerodynamic lift force. 
     
     
         12 . The method of  claim 10 , wherein the flow control device is at least one of flaps, ailerons, deployable tabs, spoilers, air jets, synthetic jets, and plasma actuators. 
     
     
         13 . A method, comprising:
 determining, by a computing device having at least one processor, a first pressure sensing location on an airfoil;   determining a second pressure sensing location on the airfoil; and   determining, by the computing device, an aerodynamic lift force associated with the airfoil based on at least one non-pressure differential parameter and only pressure differential data corresponding to the pressure differential between the first pressure location and the second pressure location.   
     
     
         14 . The method of  claim 13 , wherein the step of determining the first pressure sensing location and the second pressure sensing location includes determining the first and second location based on at least one of analytical or experimental data. 
     
     
         15 . The method of  claim 13 , wherein the step of determining the force acting normal to the chord line of the airfoil includes determining the force based on the determined difference in pressure and not based on any additional factors. 
     
     
         16 . The method of  claim 13 , wherein the first determined pressure sensing location is on a top surface of the airfoil and the second determined pressure sensing location is on a bottom surface of the airfoil. 
     
     
         17 . A wind turbine, comprising:
 a foundation;   a hub connected to the foundation; and   a plurality of wind turbine blades connected to and arranged about the hub, wherein at least one wind turbine blade includes only two pressure sensing orifices, the two pressure sensing orifices being configured to enable determination of an aerodynamic load of the at least one blade.   
     
     
         18 . The wind turbine of  claim 17 , wherein the at least one non-pressure differential parameter includes wind speed. 
     
     
         19 . The wind turbine of  claim 17 , wherein the at least one non-pressure differential parameter includes barometric pressure. 
     
     
         20 . A rotor blade comprising:
 only two pressure sensing orifices; and   a controller configured to determine an aerodynamic load of the rotor blade based on the pressure differential between the two pressure sensing orifices.