Helicopter rotor simulation via actuator line method coupled with DYMORE*

The unsteady analysis of articulated helicopter rotor operation will require massive computational resources with traditional methods. To reduce the cost, Actuator Line Method (ALM) represents each rotor blade with a line and projects the aerodynamic force onto the computational mesh in isotropic Gaussian distribution. The Immersed Boundary Method (IBM) is implemented on the fuselage for Fluid-Structure Interaction (FSI) analysis. Spalart – Allmaras (SA) model is applied to capture the turbulence in rotor wake. Advection Upstream Splitting Method (AUSM), along with Monotonic Upstream-centered Scheme for Conservation Laws (MUSCL) scheme take part in simulating the advancing blade compressibility. ALM has a well-known problem of showing unphysical sectional thrust distribution at the blade tip. The tip loss correction model presented by previous works lacked performance in diverse collective pitch angles. To simulate the feathering motion of the blade, present study implements a newer tip loss correction function with improved performance in varying collective pitch angle. In house code was developed using the above schemes and coupled with DYMORE, a finite-element based analysis of nonlinear flexible multibody systems, to compute trim condition and aeroelasticity.