Effect of Duct-Rotor Aerodynamic Interactions on Blade Design for Hover and Axial Flight

Abstract

Computational analysis of several ducted rotor systems is performed to determine the effect of rotor inflow on thrust generation in hover and axial flight. An outboard-biased rotor inflow has been shown to increase the performance of a hovering ducted rotor system. The duct-rotor aerodynamic interactions and their resulting effects on rotor inflow are studied to provide insights on duct-rotor design. Multiple duct-rotor configurations are studied using high-fidelity CFD in hover and axial flight for various twist distributions and increasing rotor collective values. Performance and efficiency gains are shown for multiple duct-rotor configurations in hover. Rotor inflow calculations show an outboard bias that allows rotors to be operated more efficiently for a range of collective angles. Benefits of outboard-biased rotor inflow in axial flight for a fixed collective were minimal. This analysis shows the extent to which performance and efficiency benefits are achieved for a ducted rotor based on the behavior of rotor inflow.

High-fidelity numerical analysis and optimisation of ducted propeller aerodynamics and acoustics

“…In recent years, Unsteady Reynolds Averaged Navier-Stokes (URANS) simulations were carried out by Jimenez and Singh et.al. [16] and by Biava and Barakos [17]. Detached Eddy Simulations (DES) and Delayed Detached Eddy Simulations (DDES) were attempted by Sheng et.al.…”

Parametric study of aerodynamic performance of equivalent ducted/un-ducted rotors

“…Unsteady Reynolds Averaged Navier-Stokes (URANS) simulations of ducted rotor flows were carried out by Jimenez and Singh et.al. [15] and by Biava and Barakos [16], more recently. Zhang and Barakos later [13] carried out extensive RANS/URANS simulations on the test case by Grunwald and Goodson [4].…”

Review on ducted fans for compound rotorcraft

“…(34) (d) Ye et al (54) (e) Xu et al (27) (f) Sheng et al (55) (g) Jimenez and Singh. (56) (h) Biava and Barakos. (57) (i) Chen et al (58) (j) Rubio et al (59) (k) Qing et al (63) on the upstream side was captured and visualised.…”

“…The study detailed the geometry and test conditions, but relevant comparisons with experiments were not included. Numerical simulations by Jimenez and Singh (56) and Singh et al (60) adopted a simplified and generalised geometry to study the ducted rotor aerodynamics through modern CFD methods (Fig. 9(g)).…”