Smaaart task order entitled: AFC-enabled vertical tail system integration study 1.0 introduction/background: the sizing of vertical tails on commercial aircraft is driven, in large part, by…

Smaaart task order entitled: AFC-enabled vertical tail system integration study 1.0 introduction/background: the sizing of vertical tails on commercial aircraft is driven, in large part, by performance required for emergency situations and/or operations near the edges of the flight envelope. Past investigations (e.g., NRA 03-larc-02) suggest that a 1-2% reduction in fuel burn over a 3000 nautical miles flight is possible for a 777-class airplane by reducing vertical tail size by 25 to 50%. As part of the environmentally responsible aviation (ERA) project, NASA is seeking to demonstrate the potential benefits of reducing vertical tail size through the use of active flow control (AFC). The AFC-enabled vertical tail would utilize AFC to provide required performance at flight conditions that drive the sizing of the vertical tail while operating in a conventional manner at all other flight conditions. Demonstrations of AFC used to increase the lifting force of aerodynamic surfaces via separation reduction have been successful at various scales and for various configurations. However, the airplane-level benefits, as well as the integration and requirements for these AFC systems, have not been sufficiently investigated to mature the technology to flight. NASA is seeking to evaluate the relative merits of selected AFC systems within the framework of the ERA program goals regarding noise, nitrous oxide emissions, and aircraft fuel burn. 2.0 scope / objectives: the overall objective of this task is to assess the integration requirements and estimate the potential system-level benefits of zero-net and positive-net mass flux AFC systems applied to a vertical tail for the purpose of increasing the tail control authority. The task should consider the aerodynamic performance, structural integration, weight, complexity, energy requirements, cost, and operational concerns of each AFC system studied. Finally, the task should consider approaches for operating AFC-based vertical tails in a flight environment. To execute this task, a baseline aircraft configuration must be established to which AFC-enabled vertical tails shall be compared. This aircraft should be representative of a member of an aircraft family that drives the sizing of the vertical tail. AFC system performance levels and requirements should be assumed as part of the system study and later evaluated against wind tunnel data as IT becomes available. AFC system hardware and associated equipment must be sized appropriately for demonstration of its integration into a full-scale vertical tail. Net present value (NPV) will be used to assess the relative benefit of the AFC systems at an airplane level. Recommendations for follow-on activity to mature the AFC technologies to flight-readiness as well as identifying technical challenges are also key outcomes of this task. The specific objectives of this task are: establish performance metrics for assessing the effectiveness of AFC on a vertical tail relative to vertical tail design and performance requirements. Establish a NPV for zero-net and positive-net mass flux AFC systems applied to a vertical tail for the purpose of reducing the required size of the vertical tail. Demonstrate how zero-net and positive-net mass flux AFC systems could be integrated into a commercial vertical tail. Identify technical challenges associated with the application of AFC to a vertical tail in a flight environment. 3.0 description of the work/tasks to be performed: the contractor shall perform the following tasks: 3.1 establish a baseline airplane configuration 3.1.1 the contractor shall describe the characteristics of the baseline airplane configuration or configurations to be used in the system study. The baseline airplane shall be of a type that would size the vertical tail and rudder for a family of airplanes. 3.2 assess critical vertical tail sizing criteria 3.2.1 the contractor shall ID