Plasma actuated cascade flow vectoring

Abstract

A system for directing airflow, a gas turbine engine, and a method for directing airflow exiting a cascade of internal airfoils are provided. An exemplary system for directing airflow includes a cascade of internal structures spanning an airflow path. Each of the internal structures includes a rounded trailing edge. The system further includes at least one plasma generating device positioned on the rounded trailing edge of each internal structure. Also, the system includes a controller configured to selectively energize and de-energize each plasma generating device to selectively alter a direction of local airflow around each internal structure to produce a combined airflow exiting the cascade in a desired direction.

What is claimed is: 
     
         1 . A system for directing airflow comprising:
 a cascade of internal structures spanning an airflow path, wherein each of the internal structures includes a rounded trailing edge;   at least one plasma generating device positioned on the rounded trailing edge of each internal structure; and   a controller configured to selectively energize and de-energize each plasma generating device to selectively alter a direction of local airflow around each internal structure to produce a combined airflow exiting the cascade in a desired direction.   
     
     
         2 . The system of  claim 1  wherein each plasma generating device is a single dielectric barrier discharge plasma actuator, wherein each internal structure has two sides, and wherein each internal structure is provided with more than one plasma actuator on each side. 
     
     
         3 . The system of  claim 1  wherein each plasma generating device is a single dielectric barrier discharge plasma actuator, wherein each internal structure has two sides, and wherein each internal structure is provided with at least one plasma actuator on one side and no plasma actuators on the other side. 
     
     
         4 . The system of  claim 1  wherein the controller is configured to energize each plasma generating device on a selected internal airfoil to move a boundary separation location of the local airflow around the selected internal structure toward the trailing edge of the selected internal structure. 
     
     
         5 . The system of  claim 1  wherein each plasma generating device is flush with the respective internal structure. 
     
     
         6 . The system of  claim 1  wherein each internal structure extends radially from a hub to a tip, and wherein each first plasma generating device extends from the hub to the tip of the respective internal structure. 
     
     
         7 . The system of  claim 1  further comprising a sensor to monitor the aerodynamics of the combined airflow exiting the cascade. 
     
     
         8 . The system of  claim 7  wherein the sensor is operatively coupled to the controller to selectively energize and de-energize each plasma generating device. 
     
     
         9 . A gas turbine engine comprising:
 a cascade of internal airfoils, wherein each of the internal airfoils includes a first surface and an opposite second surface connected at a rounded trailing edge;   a first single dielectric barrier discharge plasma actuator positioned on the first surface and the rounded trailing edge of each of the internal airfoils; and   a second single dielectric barrier discharge plasma actuator positioned on the second surface and the rounded trailing edge of each of the internal airfoils, wherein each first single dielectric barrier discharge plasma actuator and each second single dielectric barrier discharge plasma actuator are selectively energized and de-energized to selectively alter a direction of local airflow around each of the internal airfoils to produce a combined airflow exiting the cascade in a desired direction.   
     
     
         10 . The gas turbine engine of  claim 9  further comprising a controller configured to selectively energize and de-energize each first single dielectric barrier discharge plasma actuator and each second single dielectric barrier discharge plasma actuator. 
     
     
         11 . The gas turbine engine of  claim 10  wherein the controller is configured to energize the first plasma actuator and the second plasma actuator on a selected internal airfoil to move a boundary separation location of the local airflow around the selected internal airfoil toward the trailing edge of the selected internal airfoil. 
     
     
         12 . The gas turbine engine of  claim 9  further comprising a power supply electrically coupled to the first plasma actuator and the second plasma actuator on each of the internal airfoils. 
     
     
         13 . The gas turbine engine of  claim 9  wherein the first plasma actuator is flush with the first surface and the rounded trailing edge of each respective internal airfoil, and wherein each second plasma actuator is flush with the second surface and the rounded trailing edge of each respective internal airfoil. 
     
     
         14 . The gas turbine engine of  claim 9  wherein each internal airfoil extends radially from a hub to a tip, and wherein the first plasma actuator and the second plasma actuator extend from the hub to the tip of each internal airfoil. 
     
     
         15 . The gas turbine engine of  claim 9  further comprising a sensor to monitor the aerodynamics of the combined airflow exiting the cascade. 
     
     
         16 . The gas turbine engine of  claim 15  wherein the sensor is operatively coupled to the controller to cause the power supply to selectively energize and de-energize the first plasma actuator and the second plasma actuator on a selected internal airfoil. 
     
     
         17 . A method for directing airflow exiting a cascade of internal airfoils comprising:
 coupling a first plasma generating device on a first surface and a rounded trailing edge of each of the internal airfoils;   coupling a second plasma generating device on an opposite second surface and the rounded trailing edge of each of the internal airfoils; and   selectively energizing the first plasma generating device and the second plasma generating device on each of the internal airfoils to produce a plasma and to selectively alter a direction of local airflow around each of the internal airfoils to produce a combined airflow exiting the cascade in a desired direction.   
     
     
         18 . The method of  claim 17  wherein selectively energizing the first plasma generating device and the second plasma generating device on each of the internal airfoils moves a boundary separation location of the local airflow around each of the internal airfoils toward the trailing edge of each of the internal airfoils. 
     
     
         19 . The method of  claim 18  further comprising monitoring the aerodynamics of the combined airflow exiting the cascade. 
     
     
         20 . The method of  claim 19  further comprising selectively de-energizing the first plasma generating device and the second plasma generating device on each of the internal airfoils in response to the monitored aerodynamics of the combined airflow exiting the cascade to alter the combined airflow exiting the cascade.