The helicopter tail shake phenomenon is an area of great concern to helicopter manufacturers as it adversely affects the overall performance and handling qualities of the helicopter, and the comfort of its occupants. This study aims to gain information of the flow field that governs helicopter tail shake phenomenon which has frequently puzzled the aerodynamicists. Using Computational Fluid Dynamic (CFD) approach, the Multiple Reference Frames (MRF) method was applied to simulate the helicopter’s main-rotor-hub assembly rotation. In this study, the aerodynamic flow field was computed using the Reynolds-Averaged Navier-Stokes (RANS) equations. As the induced wake, which consequently causing tail to shake differs with the rpm of main-rotor-hub assembly, this preliminary numerical investigation was performed ranging from rpm of 0 to 900, with intervals of 300 rpm. A rotor-hub-fairing which covers partly the main-rotor-hub assembly was also employed to examine its effect on the wake unsteadiness. Results tell the rotation of main-rotor-hub assembly and pylon do significantly influencing the flow unsteadiness.
Department of Aeronautics, Automotive and Ocean Engineering, Universiti Teknologi Malaysia, Malaysia
Basic concept of aircraft wing design is based on airfoil section. Time flies, evolution in aircraft wing design shows the desire of mankind to improve the speed, agility, maneuverability of an aircraft. It is proven that aircraft with delta or double delta wing design fulfill this desire. Basic concept of delta wing is triangular planform of the wing that same with the Greek symbol (Δ) and double delta wing is delta wing with a ‘kink’ or leading edge extension. This research aims is to obtain aerodynamic characteristic (Cl, Cd) of double delta wing using computational fluid dynamic and compare the result with wind tunnel experiment. In this work, the geometry of the double delta wing used was constructed using 2 x 106unstructed mesh elements. Turbulence model that been used in this research is k-ω turbulence model. The simulation was run at Reynolds Number of 1 x 106 and 2 x 106 and with variation of pitch angle from 0 to 20.
Department of Aeronautics, Automotive and Ocean Engineering, Universiti Teknologi Malaysia, Malaysia
This paper presents the computational analysis of three dimensional (3D) flow over the generic model of Bell 206B helicopter tail rotor blades using ANSYS Fluent Computational Fluid Dynamics (CFD) package. This simulation work deals with the comparative study of variation in an angle of attack over the blade atdifferent speed which using the k–ω shear stress transport (SST) model. The model is utilized to predict the flow accurately along with turbulence intensities 5% and 5% at velocity inlet and pressure outlet respectively. The meshing 3D geometry was performed on ICEM CFD package of ANSYS and the simulation was executed in the FLUENT package of ANSYS. The simulation results were validated by comparing with the experimental result that have already done before.
Department of Aeronautics, Automotive and Ocean Engineering, Universiti Teknologi Malaysia, Malaysia
