Aerodynamic Modeling of Propeller Forces and Moments at High Angle of Incidence

Abstract

A reduced-order model to estimate the aerodynamic forces and moments of a propeller at incidence angle from 0 • to 90 • was presented. The objective was to provide an inexpensive and effective approach to analyse propeller performance of a vertical/short take-off and landing aerial vehicle during transition flight. The model was based on blade element theory and was coupled with an extended momentum theory or Pitt & Peters inflow model to include the asymmetrical flow condition. The aerofoil aerodynamic data was provided by an empirical model that extended lift and drag polar to a broad angle-of-attack range suitable in transition flight. Furthermore a rotational stall delay model and a radial flow correction model have been incorporated to include primary 3-dimensional effects. The result has been presented and compared with past experiment and unsteady Reynolds-averaged Navier-Stokes solution under similar conditions.(a) ISAE MAVION [1] (b) Boeing-Bell V-22 Osprey [2]

Numerical Investigation of a Two-Bladed Propeller Inflow at Yaw

“…An improvement on these models was derived in 1980 by Pitts and Peters [20,21], where the induced velocity at the propeller plane is calculated based upon a truncated Fourier series and works under the assumption of the superposition of pressure. Studies have been conducted in recent times [22] with consistent results of forces and moments found in axial and yawed test conditions whilst using the Pitts and Peters model. The Pitts and Peters is a dynamic inflow model and it requires additional coupling to a blade element like model in order to obtain propeller blade loads.…”

Numerical predictions of low Reynolds number compressible aerodynamics

“…As such, despite the relatively good agreement observed on figure 11, VLM should not be viewed as an accurate method for high pitch angles where separation occurs at the leading edge. Note however that special treatment of the two-dimensional polars used in VLM can be added to account for rotational effects on LEV stability [19].…”

Analytic Model of Proprotor Forces and Moments at High Incidence

“…The figures were obtained through in-house calculations on similar low Reynolds number proprotor cases over a limited test conditions (Refs. 9,22,23).…”