Computational Study of a Transverse Rotor Aircraft in Hover Using the Unsteady Vortex Lattice Method

Abstract

This paper presents the simulation of a two-rotor aircraft in different geometric configurations during hover flight. The analysis was performed using an implementation of the unsteady vortex-lattice method (UVLM). A description of the UVLM is presented as well as the techniques used to enhance the stability of results for rotors in hover flight. The model is validated for an isolated rotor in hover, comparing numerical results to experimental data (high-Reynolds, low-Mach conditions). Results show that an exclusion of the root vortex generates a more stable wake, without affecting results. Results for the two-rotor aircraft show an important influence of the number of blades on the vertical thrust. Furthermore, the geometric configuration has a considerable influence on the pitching moment.

Numerical and Experimental Estimation of the Efficiency of a Quadcopter Rotor Operating at Hover

“…The pressure jump at each control point is calculated using non-dimensional quantities (for details, see Ref. [13]); therefore, Equation (16) becomes Equation (17)…”

“…From the pressure distribution, it is possible to calculate the acting force C f (Equation (18)) and moment C m (Equation (19)) coefficients [13]:…”

“…Details of the implementation of the slow-starting method can be found in Ref. [13]. After the slow-start phase, the simulations were run for at least eight revolutions with a time step ∆t that corresponds to a rotation of 10 • .…”

“…Colmenares, López and Preidikman [13] developed the GUAVLAM code based on UVLM to simulate the potential flow around a lifting surface. The code was tested by simulating two rectangular untwisted blades.…”

PyFly: A fast, portable aerodynamics simulator

“…This approach applies only to ideal fluids (i.e., those involved in incompressible, inviscid, and irrotational flows), where the separation lines are known a priori. UVLM has been widely used for the analysis and design of avian-like flapping wings in forward and hover flights [5][6][7][8][9][10][11][12], modeling wind turbines [13][14][15][16][17][18], dynamic analysis of offshore structures [19][20][21] and control and vibration suppression of civil engineering structures [22,23].…”