Current Status of U.S. Army Comprehensive Helicopter Analysis System

The Second Generation Comprehensive Helicopter Analysis System (2GCHAS) is a comprehensive, multi-disciplinary helicopter analysis software tool for prediction of the performance, stability, vibration and flight controls. The structural system is based on finite element analysis, coupled with various aerodynamic options for modeling flexibility. This paper briefly describes recent development of new functionalities incorporated into the 2GCHAS version 3.0; a NASTRAN fuselage model, coupling of the Computation Fluid Dynamics (CFD) full potential rotor code (FPX) with the computational Structural Dynamics (CSD) code, the Panel Method Ames Research Center (PMARC) fuselage panel model, and the on-blade elevon control model. A series of correlation studies have been conducted in order to validate this new and/or existing functionality in 2GCHAS. The correlation data were selectively presented from UH-60A Black Hawk, HART (Higher-harmonic-control Aeroacoustic Rotor Test), and CH-47D data. Overall, extensive correlation efforts have been made for a wide range of complex aeromechanics problems to validate the 2GCHAS software.