Aircraft Conceptual Design Capability with Fast, High-Order Aeromechanics Models

ABSTRACT: Requirements for enhanced cruise efficiency and reduced noise for future Air Force mobility transports can be met using advanced propeller and propfan technology. However, identifying designs that balance performance and acoustics requirements for multiple flight conditions poses a serious analytical challenge, given structural constraints, weight considerations, and drivetrain interactions. Supporting conceptual and preliminary designs thus requires fast-turnaround models appropriate for analysis of a wide design and operational space without sacrificing physical fidelity. A first step in addressing this need involves development of a multidisciplinary design environment that captures key aerodynamic and acoustic interactions, building on the demonstrated capabilities of the CDI CHARM model in proprotor and propeller design. This model can capture complex unsteady interactions of multiple propellers and airframe components and includes a validated noise prediction capability. Extensions of this model for propellers in transonic flight and their integration with current-generation sizing and design tools will lay the foundation for a design capability that can address key performance and acoustics metrics. Phase I will demonstrate optimization of propeller performance subject to noise constraints in multiple flight conditions while incorporating realistic wing and airframe interference, laying the groundwork for a more general multidisciplinary model in Phase II. BENEFIT: Potential Air Force Applications Immediate applications of the projected technology will be the ability to refine designs of propeller systems for retrofit to current generation aircraft. Maximum impact will occur, however, with the application of the projected tools to design of new mobility platforms, including the Advanced Theater Transport that can enhance Air Force transport capabilities. Potential Civil Applications Increased fuel costs have revived interest in applications of advanced turboprop and open rotor designs in recent years. Acoustics goals to satisfy current and projected civil aviation noise standards are stringent, however; thus, the potential market for a high-fidelity, fast-turnaround propeller design optimization analysis is considerable if coupled to a validated acoustic prediction capability.