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The purpose of this paper is to investigate the influence of a propeller slipstream on the aerodynamic characteristics of a fixed-wing micro air vehicle (MAV) by simplifying a propeller to an actuator disk and an actuator volume.

A computational fluid dynamic (CFD) approach.

The simulation flows are found and show that the propeller slipstream changes the flow field around the wing, which improves the aerodynamic performance of the wing. The aerodynamic performance is improved first, when the separation of the boundary flow at the upper surface wing is delayed. Second, the flow region of the boundary layer is boosted close to the wing surface again at a high incidence angle. And finally, the velocity inlet of the wing is increased by the propeller-induced flow.

The incidence angle is in the range of 0-80°with an increment of 20°. The free stream velocity and RPM used are 6 m/s and 5,000 rpm, respectively.

A propeller is simplified to an actuator disk and an actuator volume.

The traditional numerical methods to predict the interaction between the wing and propeller are too complex and time-consuming for computation to a certain extent. Therefore, they are not applicable for a real-time integrated turboprop aircraft model. This paper aims to present a simplified model capable of high-precision and real-time computing.

A wing model based on the lifting line theory coupled with a propeller model based on the strip theory is used to predict the propeller-wing interaction. To meet the requirement of real-time computing, a novel decoupling parameter is presented to replace lifting line model (LLM) applied for wings with a simplified fitting model (FM).

The comparison between the LLM and the simplified FM demonstrates that the results of the FM have a good agreement with the results of the LLM, which means that the simplified FM has the advantages of both high-accuracy and real-time computation.

After simplification, the propeller-wing interaction model is suitable for a real-time integrated turboprop aircraft model.

A novel decoupling parameter is presented to replace LLM applied for wings with a simplified FM, which has the advantages of both high-accuracy and real-time computation.

This study aims to investigate the effects of propeller locations on the aerodynamic characteristics of a generic 55° swept angle sharp-edged delta wing unmanned aerial vehicle (UAV) model.

A generic delta-winged UAV model has been designed and fabricated to investigate the aerodynamic properties of the model when the propeller is placed at three different locations. In this research, the propeller has been placed at three different positions on the wing, namely, front, middle and rear. The experiments were conducted in a closed-circuit low-speed wind tunnel at speeds of 20 and 25 m/s corresponding to 0.6 × 10⁶ and 0.8 × 10⁶ Reynolds numbers, respectively. The propeller speed was set at constant 6,000 RPM and the angles of attack were varied from 0° to 20° for all cases. During the experiment, two measurement techniques were used on the wing, which were the steady balance measurement and surface pressure measurement.

The results show that the locations of the propeller have significant influence on the lift, drag and pitching moment of the UAV. Another important observation obtained from this study is that the location of the propeller can affect the development of the vortex and vortex breakdown. The results also show that the propeller advance ratio can also influence the characteristics of the primary vortex developed on the wing. Another main observation was that the size of the primary vortex decreases if the propeller advance ratio is increased.

There are various forms of UAVs, one of them is in the delta-shaped planform. The data obtained from this experiment can be used to understand the aerodynamic properties and best propeller locations for the similar UAV aircrafts.

To the best of the author’s knowledge, the surface pressure data available for a non-slender delta-shaped UAV model is limited. The data presented in this paper would provide a better insight into the flow characteristics of generic delta winged UAV at three different propeller locations.

Recent interest in electric aircraft has opened avenues for exploring innovative concepts and designs. Because of its potential to increase wing aerodynamic efficiency, the idea of wing tip-mounted propellers is becoming more popular in the context of electric aircraft. This paper aims to address the question of which configuration, tractor or pusher at wing tip is more beneficial.

The interactions between the wing and tip-mounted propellers in tractor and pusher configurations have been studied computationally. In this study, the propeller is modeled as a disk, and the blade element method (BEM) coupled with the computational fluid dynamics (CFD)–Reynolds-averaged Navier–Stokes (RANS) solver is used to calculate propeller blade loading recursively. A direct comparison between the wing with tip-mounted propellers in tractor and pusher configurations is made by varying the direction of rotation and thrust.

Wing with tip-mounted propellers having inboard-up rotation is found to offer less drag in tractor and pusher configurations than those without propeller cases. Wing tip-mounted propeller in tractor configuration with inboard-up rotation offers higher wing aerodynamic efficiency than the other configurations. In tractor and pusher configurations with inboard-up rotating propellers, wing tip vortex attenuation is seen, whereas with outboard-up rotating propellers, the wing tip vortex amplification is observed.

SU2, an open-source CFD tool, is used in this study and BEM is coupled to perform RANS–BEM simulations. Both qualitative and quantitative comparisons were made between the tractor and pusher configurations, which may find its value when a question arises about the aerodynamically best propeller configuration at wing tips.

This is the first of two companion papers presenting the results of research into a contra‐rotating propeller designed to drive a super manoeuvrable micro air vehicle (MAV). The purpose of this first paper is to describe the design process and numerical analyses. The second paper is devoted to the experimental results verifying the computations.

Software based on the analytical formulas derived by Theodore Theodorsen was used in the design procedure. Three‐dimensional finite‐volume simulation, performed with the use of commercial software verified the results. Finally, two‐dimensional simulation was conducted to explore the effect of the propeller‐wing interaction. The meshes applied in these analyses are described.

Propeller geometry received as a result of the design procedure is presented. The computation results for different turbulence models applied are discussed. Time dependent characteristics of contra‐rotating propeller are presented as well as conclusions regarding propeller‐wing interaction.

Propeller was designed for a fixed wing aeroplane, not for helicopter rotor. Therefore, conditions characteristic for fixed wing aeroplane flight are analysed only. Reynolds numbers below 50000 are considered.

Designed contra‐rotating propeller can be used in fixed wing aeroplane if torque equal to zero is required. Software based on the formulas derived by T. Theodorsen can be used to design the propellers.

Software applied in the design procedure was originally developed by one of authors although it is based on the formulas derived by T. Theodorsen. Contra‐rotating propeller simulation results for different turbulence models are discussed for the first time. Moreover, unique time dependent characteristics of contra‐rotating propeller are presented.

Rotor performance analysis and design are complex due to the wide variation in flow characteristics. Design tools that can rapidly and accurately compute aerofoil data are needed for rotorcraft design and analysis purposes. The purpose of this paper is to describe a process which has been developed that effectively automates the generation of two‐dimensional (2D) aerofoil characteristics tables.

The process associates a number of commercial software packages and in‐house codes that employ diverse methodologies, including the Navier‐Stokes equation‐solving method, the high‐order panel method and Euler equations solved with the fully coupled viscous‐inviscid interaction (VII) method. The paper describes the development of a general automated generation method that extends from aerofoil shape generation to aerofoil characteristic analysis. The generated data are stored in C81 aerofoil characteristics tables for use in comprehensive rotorcraft analysis codes and rotor blade design. In addition, the methodology could be easily applied for fixed‐wing analysis and design, especially for transonic aircraft.

The method is demonstrated to achieve aerofoil characteristics quickly and accurately in automated process. Calculations for the SC1095 aerofoil section are presented and compared with existing experimental C81 data and previous studies.

The development of C81 tables is of interest to industry as they seek to update their airfoil tables as new designs. Automated processes to achieve this are helpful and applicable.

The paper presents an effective automated process to generate aerofoil characteristics tables quickly, and accurately.

Under this heading are published regularly abstracts of all Reports and Memoranda of the Aeronautical Research Council, Reports and Technical Memoranda of the United States National Advisory Committee for Aeronautics and publications of other similar Research Bodies as issued.

The paper deals with research activities to develop optimization workflows implying computational fluid dynamics (CFD) modelling. The purpose of this paper is to present an industrial and fully-automated optimal design tool, able to handle objectives, constraints, multi-parameters and multi-points optimization on a given CATIA CAD. The work is realized on Rapid And CostEffective Rotorcraft compound rotorcraft in the framework of the Fast RotorCraft Innovative Aircraft Demonstrator Platform (IADP) within the Clean Sky 2 programme.

The proposed solution relies on an automated CAD-CFD workflow called through the optimization process based on surrogate-based optimization (SBO) techniques. The SBO workflow has been specifically developed.

The methodology is validated on a simple configuration (bended pipe with two parameters). Then, the process is applied on a full compound rotorcraft to minimize the flow distortion at the engine entry. The design of the experiment and the optimization loop act on seven design parameters of the air inlet and for each individual the evaluation is performed on two operation points, namely, cruise flight and hover case. Finally, the best design is analyzed and aerodynamic performances are compared with the initial design.

The adding value of the developed process is to deal with geometric integration conflicts addressed through a specific CAD module and the implementation of a penalty function method to manage the unsuccessful evaluation of any individual.

The overall performance of an aerial vehicle strongly depends on the specifics of the propulsion system and its position relative to the other components. The purpose of paper is this factor can be characterized by changing several contributing parameters, such as distance from the ground, fuselage and wing as well as the nacelle outlet velocity and analyzing the aerodynamic performance.

Navier–Stokes equations are discretized in space using finite volume method. A KW-SST model is implemented to model the turbulence. The flow is assumed steady, single-phase, viscous, Newtonian and compressible. Accordingly, after validation and verification against experimental and numerical results of DLRF6 configuration, the location of the propulsion system relative to configuration body is examined.

At the nacelle outlet velocity of V/V_inf = 4, the optimal location identified in this study delivers 16% larger lift to drag ratio compared to the baseline configuration.

Altering the position of the propulsion system along the longitudinal direction does not have a noticeable effect on the vehicle performance.

Aerial vehicles including wing-in-ground effect vehicles require thrust to fly. Generating this necessary thrust for motion and acceleration is thoroughly affected by the vehicle aerodynamics. There is a lack of rigorous understanding of such topics owing to the immaturity of science in this area. Complexity and diversity of performance variables for a numerical solution and finding a logical connection between these parameters are among the related challenges.

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