Aerodynamic Performance and Static Stability Characteristics of Aircraft with Tail-Mounted Propellers

In this combined experimental and numerical study, the propeller–airframe aerodynamic interaction is characterized for an aircraft configuration with propellers mounted to the horizontal tailplane. The contributions of the propeller and airframe to the overall loading are distinguished in the experimental analyses by using a combination of...

Experimental Investigation of Over-the-Wing Propeller–Boundary-Layer Interaction

This experimental study focuses on the aerodynamic interaction between an over-the-wing (OTW) propeller and a wing boundary layer. An OTW propeller is positioned above the hinge line of a wing with a trailing-edge flap. Measurements are carried out with and without axial pressure gradients by deflecting the flap and by extending the flat upper...

Numerical Investigation of Propeller–Flap Interaction in Inclined Over-the-Wing Distributed-Propulsion Systems

In this study, unsteady RANS simulations are performed to investigate the effect of over-the-wing (OTW) propeller inclination on the aerodynamic interaction with a wing featuring a plain flap. A comparison to experimental data shows that the numerical approach is capable of modeling the wing and propeller separately and can capture the effect of...

Aerodynamic interaction between propellers of a distributed-propulsion system in forward flight

This article describes an experimental investigation of the aerodynamic interaction that occurs between distributed propellers in forward flight. To this end, three propellers were installed in close proximity in a wind tunnel, and the changes in their performance, flow-field characteristics, and noise production were quantified using...

Engineering method to estimate the blade loading of propellers in nonuniform flow

Advances in aerodynamic and propulsive efficiency of future aircraft can be achieved by strategic installation of propellers near the airframe. This paper presents a robust and computationally efficient engineering method to estimate the load distribution of a propeller operating in arbitrary nonuniform flow that is induced by the airframe...

Aerodynamic Performance and Interaction Effects of Circular and Square Ducted Propellers

Ducted propellers constitute an efficient propulsion-system alternative to reduce the environmental impact of aircraft. These systems are able to increase the thrust-to-power ratio of a propeller system by both producing thrust and by lowering tip losses of propellers. In this research, steady and unsteady RANS CFD simulations were used to...

Conceptual Assessment of Hybrid Electric Aircraft with Distributed Propulsion and Boosted Turbofans

This paper presents the results of a study into the effect of distributed hybrid-electric propulsion on aircraft performance and characteristics. To size these aircraft, a new preliminary sizing method for hybrid-electric aircraft with distributed propulsion, including aero-propulsive interaction, is combined with a modified Class-II weight...

Aerodynamic Interaction Between an Over-the-Wing Propeller and the Wing Boundary-Layer in Adverse Pressure Gradients

This experimental study focuses on the aerodynamic interaction effects that occur between an over-the-wing (OTW) propeller and a wing boundary-layer. An OTW propeller is positioned above the hinge-line of a wing featuring a plain flap. The measurements are carried out with and without axial pressure gradients by deflecting the flap and by...

Aerodynamic Performance of an Aircraft Equipped with Horizontal Tail-Mounted Propellers

This paper presents an experimental and numerical study of the aerodynamic interaction between horizontal tail-mounted propellers and the airframe. A representative aircraft model was installed in a low-speed wind-tunnel and measurements were taken with an external balance to determine the effect of propeller installation on integral forces...

Alleviation of Propeller-slipstream-induced unsteady pylon loading by a flow-permeable leading edge

The impingement of a propeller slipstream on a downstream surface causes unsteady loading, which may lead to vibrations responsible for structure-borne noise. A low-speed wind-tunnel experiment was performed to quantify the potential of a flow-permeable leading edge to alleviate the slipstream-induced unsteady loading. For this purpose, a...

Aerodynamic investigation of an over-the-wing propeller for distributed propulsion

This paper addresses the aerodynamic performance and numerical modeling of over-the-wing propellers. Installing the propeller above a wing has the potential to increase wing lift-to-drag ratio, high-lift capabilities, and to reduce flyover noise. However, the prediction of its performance is difficult, since research on the aerodynamic...

Unsteady pylon loading caused by propeller-slipstream impingement for tip-mounted propellers

An experimental analysis was performed of the unsteady aerodynamic loading caused by the impingement of a propeller slipstream on a downstream lifting surface. When installed on an aircraft, this unsteady loading results in vibrations that are transmitted to the fuselage and are perceived inside the cabin as structure-borne noise. A pylon...

Tractor Propeller-Pylon Interaction, Part I: Characterization of Unsteady Pylon Loading

<br/>

Tractor Propeller-Pylon Interaction, Part II: Mitigation of Unsteady Pylon Loading by Application of Leading-Edge Porosity

<br/>