Coupling of a multibody simulation tool for the analysis of rotary systems with a panel based flow solver and a navier-stokes flow solver

Download

index.pdf

Date

2018

Author

Soğancı, Semih

Metadata

Show full item record

Item Usage Stats

320
views

140
downloads

In rotorcraft design, aeroelastic effects on the main rotor blades play a critical role in the accurate estimation of the external loading acting on the structure. The external loading is mainly due to the aerodynamic loads and the inertial loads on the main rotor blades. High aspect ratio blades largely deform in flapping direction on top of rigid body flapping, and due to the rigid and elastic flapping motion, the airloads acting on the blades change continuously. Hence, the rotor blade loads analysis should be interdisciplinary relying on the nonlinear structural dynam ics, the aerodynamics and the control. A flexible multibody dynamics solver, DYMORE, is used as a comprehensive analysis tool for rotor simulations. Aerodynamic loads are internally calculated from two dimensional aerodynamic tables which give the aerodynamic coefficients based on the angle of attack and the Mach number. In the aerodynamic shape optimization of blade profiles, at each iteration in the shape optimization, sections are perturbed and for the perturbed sections aerodynamic loads can not be calculated using the look-up tables since these tables are for a certain airfoil shape. Therefore, there is a need for an aerodynamic solver to provide the solution for the perturbed sections. In this study, the internal aerodynamic module of DYMORE is replaced first with a panel based flow solver, XFOIL, and then a Reynolds Averaged Navier-Stokes (RANS) solver, SU2. At each section, the aerodynamic load coefficients obtained from XFOIL and SU2 are used instead of interpolated table coefficients. XFOIL and SU2 source codes are embedded into DYMORE and compiled together using the C-FORTRAN interoperability functions and the external data structures with assigned pointers. The simulations are carried out for an isolated rotor in hover. UH-60 main rotor architecture is modeled and NACA 0012 profile is used for blade sections. Validation studies are carried out at Mach numbers of 0.4 and 0.7 for the angle of attack range of 0 to 15 degrees. The lift and drag coefficients obtained from XFOIL and SU2 are in good agreement with the table values. Hub airloads and blade angles obtained from the coupled analyses are also in close correlation with the internal aerodynamic results.

Subject Keywords

Computational fluid dynamics., Rotors (Helicopters)., Aerodynamics.

URI

http://etd.lib.metu.edu.tr/upload/12622262/index.pdf
https://hdl.handle.net/11511/27413

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

Computational fluid dynamics simulations of ship airwake with a hovering helicopter rotor Orbay, Ezgi; Uzol, Oğuz; Sezer Uzol, Nilay; Department of Aerospace Engineering (2016) In this thesis, Computational Fluid Dynamic simulations of ship airwake for a simple ship geometry are performed for the horizontal and inclined deck configurations and also with and without the helicopter rotor over the deck. An actuator disk model is used for the CFD simulations of a rotor model hovering over the flight deck. All of the computations are performed by using a commercial finite volume CFD flow solver. The unstructured tetrahedral grids are generated in the computational domain including ship...
Analysis of hypersonic flow using three dimensional navier-stokes equations Özgün, Muharrem; Eyi, Sinan; Department of Aerospace Engineering (2016) Metallic materials in aerospace structures are exposed to impact type loads depending on their usage area. High strain rate material characterization of metallic materials is very crucial to properly prepare finite element models to be used in impact loading situations. Johnson-Cook material model is a suitable material model to represent the behaviour of metallic materials at high strain rates. In the present thesis study, parameters of the Johnson-Cook material model for Al 7075-T651 are determined utiliz...
Structural optimization of composite helicopter rotor blades Işık, Alperen Ayberk; Kayran, Altan; Department of Aerospace Engineering (2018) Structural optimization of a helicopter rotor blade with uniform aerodynamic surface and twist at the functional region is performed for weight minimization subject to various constraints relevant to helicopter rotor blades. The genetic algorithm based optimization is performed only for the functional region of the blade. Design variables are taken as the number of unidirectional S-glass layers in the spar cap, position of the spar web with respect to the leading edge, nose mass diameter and position of the...
Investigation of missiles with strake fins and reduction of aerodynamic cross coupling effects by optimization Usta, Engin; Tuncer, İsmail Hakkı; Department of Aerospace Engineering (2015) Missiles with very low aspect ratio fins (also called strakes) are generally difficult to model by using engineering level aerodynamic methods and linear theories break due to complex nature of the flow adjacent to the mutual interference of the body and fin. Since fast prediction methods cannot accurately model vortex development along and downstream of very low aspect ratio fins, they have limited success for application to missiles with strake fins. Moreover, there is limited number of CFD studies for in...
Improving flow structure and natural convection within fin spacings of plate fin heat sinks Özet, Mehmet Erdem; Tarı, İlker; Department of Mechanical Engineering (2015) The main objectives of this thesis are to numerically investigate the previously observed recirculation zones and longitudinal vortices that occur in low fin height plate finned horizontal heat sinks and to improve the flow structures and heat transfer in these zones using various approaches with the help of simulations performed using commercially available CFD software. The approaches used for improvements are replacing the outer most fins with higher ones, introducing gaps on the length of the fins in va...

Citation Formats

S. Soğancı, “Coupling of a multibody simulation tool for the analysis of rotary systems with a panel based flow solver and a navier-stokes flow solver,” M.S. - Master of Science, Middle East Technical University, 2018.