Abstract
This paper conducts the aeromechanics study using the two different rotorcraft computational structural dynamics (CSD) codes, CAMRAD II and DYMORE II, for the rotor in low-speed descending flight. The three test cases of the HART (Higher-harmonic control aeroacoustic rotor test) I -baseline, minimum noise, and minimum vibration- are considered in this study of the blade-vortex interaction (BVI) airloads, rotor trim, blade elastic deformations, and blade structural loads. The two prediction results are compared to each other for a code-to-code comparison study as well as to the measured data. Although CAMRAD II and DYMORE II use different theories and models, most of the prediction results are similar to each other and compared fairly well with the wind tunnel test data. For all the three test cases, the two rotorcraft CSD analyses show good prediction on the fluctuations of the section normal force (M2Cn) due to BVI, but both over-predict the trimmed collective pitch angle. The blade elastic deformations, such as flap deflection and elastic torsion deformation at the tip, are reasonably predicted by both rotorcraft CSD analyses. But, the CAMRAD II result using the multiple-trailer wake model with consolidation is slightly better than the DYMORE II prediction with the single wake panel model particularly for the elastic torsion deformation in the baseline case. In addition, CAMRAD II and DYMORE II both correlate reasonably the blade structural loads, such as flap bending, lead-lag bending, and torsion moments, with the measured data; however, the CAMRAD II results are moderately better than the DYMORE II predictions.
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Recommended by Associate Editor Cheolung Cheong
Jae-Sang Park received Ph.D. degree in mechanical and aerospace engineering from Seoul National University, Seoul, Korea in 2006. From 2006 to 2007, he worked as a post doctor at Flight Vehicle Research Center, Seoul National University. From 2008 to 2013, he worked for the International Rotorcraft R&D Hub at Konkuk University, Seoul, Korea. Dr. Park is currently an assistant professor, Department of aerospace engineering, Chungnam National University, Daejeon, Korea. His research interests include aeroelasticity, rotorcraft aeromechanics and smart structures.
Young Jung Kee received his M.S. and Ph.D. degrees in mechanical and aerospace engineering from Seoul National University in 2003 and 2015, respectively. Since 2003, he has been a research engineer at the Rotorcraft Research team in Korea Aerospace Research Institute. His research interests include rotorcraft dynamics, static and fatigue tests of composite structures.
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Park, JS., Kee, Y.J. Code-to-code comparison study on rotor aeromechanics in descending flight. J Mech Sci Technol 29, 3153–3163 (2015). https://doi.org/10.1007/s12206-015-0714-9
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DOI: https://doi.org/10.1007/s12206-015-0714-9