UH-60A Airloads Workshop—Setting the Stage for the Rotorcraft CFD/CSD Revolution, Part II: Ongoing Progress, Impact, and Lessons Learned

The UH-60A Airloads Workshop was a unique collaboration of aeromechanics experts from the U.S. Government, industry, and academia to address technical issues that hindered accurate rotor loads predictions. The Airloads Workshop leveraged the NASA/Army UH-60A Airloads flight test and NFAC wind tunnel test data. It functioned continuously for 17 years, from 2001 to 2018, and brought about one of the most important advancements in rotorcraft aeromechanics prediction capabilities by successfully demonstrating high-fidelity coupled computational fluid dynamics (CFD) and computational structural dynamics (CSD) analyses for both steady and maneuvering flight. The article is divided into two parts. Part I surveys the background of rotorcraft CFD/CSD development difficulties, the origins of the Airloads Workshop, and the rapid success achieved during the first phase that consisted of eight Workshops. Part II describes ongoing development during the subsequent two phases of the Airloads Workshop, the Ninth through the 13th, and the 14th through the 31st Workshops. Part II outlines development of CFD/CSD methods to predict rotor airloads for the challenging maneuvering flight condition and also describes the impact of the newly developed CFD/CSD methods and how they were transferred to the larger technical community, opening the door for practical application of CFD methods for designing future advanced rotorcraft. Part II concludes with a discussion of why the Airloads Workshop succeeded and lessons learned from the collaborative effort.